/*
This file is part of Ext JS 3.4

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-04-03 15:07:25
*/
/**
 * @class Ext.data.Store
 * @extends Ext.util.Observable
 * <p>The Store class encapsulates a client side cache of {@link Ext.data.Record Record}
 * objects which provide input data for Components such as the {@link Ext.grid.GridPanel GridPanel},
 * the {@link Ext.form.ComboBox ComboBox}, or the {@link Ext.DataView DataView}.</p>
 * <p><u>Retrieving Data</u></p>
 * <p>A Store object may access a data object using:<div class="mdetail-params"><ul>
 * <li>{@link #proxy configured implementation} of {@link Ext.data.DataProxy DataProxy}</li>
 * <li>{@link #data} to automatically pass in data</li>
 * <li>{@link #loadData} to manually pass in data</li>
 * </ul></div></p>
 * <p><u>Reading Data</u></p>
 * <p>A Store object has no inherent knowledge of the format of the data object (it could be
 * an Array, XML, or JSON). A Store object uses an appropriate {@link #reader configured implementation}
 * of a {@link Ext.data.DataReader DataReader} to create {@link Ext.data.Record Record} instances from the data
 * object.</p>
 * <p><u>Store Types</u></p>
 * <p>There are several implementations of Store available which are customized for use with
 * a specific DataReader implementation.  Here is an example using an ArrayStore which implicitly
 * creates a reader commensurate to an Array data object.</p>
 * <pre><code>
var myStore = new Ext.data.ArrayStore({
    fields: ['fullname', 'first'],
    idIndex: 0 // id for each record will be the first element
});
 * </code></pre>
 * <p>For custom implementations create a basic {@link Ext.data.Store} configured as needed:</p>
 * <pre><code>
// create a {@link Ext.data.Record Record} constructor:
var rt = Ext.data.Record.create([
    {name: 'fullname'},
    {name: 'first'}
]);
var myStore = new Ext.data.Store({
    // explicitly create reader
    reader: new Ext.data.ArrayReader(
        {
            idIndex: 0  // id for each record will be the first element
        },
        rt // recordType
    )
});
 * </code></pre>
 * <p>Load some data into store (note the data object is an array which corresponds to the reader):</p>
 * <pre><code>
var myData = [
    [1, 'Fred Flintstone', 'Fred'],  // note that id for the record is the first element
    [2, 'Barney Rubble', 'Barney']
];
myStore.loadData(myData);
 * </code></pre>
 * <p>Records are cached and made available through accessor functions.  An example of adding
 * a record to the store:</p>
 * <pre><code>
var defaultData = {
    fullname: 'Full Name',
    first: 'First Name'
};
var recId = 100; // provide unique id for the record
var r = new myStore.recordType(defaultData, ++recId); // create new record
myStore.{@link #insert}(0, r); // insert a new record into the store (also see {@link #add})
 * </code></pre>
 * <p><u>Writing Data</u></p>
 * <p>And <b>new in Ext version 3</b>, use the new {@link Ext.data.DataWriter DataWriter} to create an automated, <a href="http://extjs.com/deploy/dev/examples/writer/writer.html">Writable Store</a>
 * along with <a href="http://extjs.com/deploy/dev/examples/restful/restful.html">RESTful features.</a>
 * @constructor
 * Creates a new Store.
 * @param {Object} config A config object containing the objects needed for the Store to access data,
 * and read the data into Records.
 * @xtype store
 */
Ext.data.Store = Ext.extend(Ext.util.Observable, {
    /**
     * @cfg {String} storeId If passed, the id to use to register with the <b>{@link Ext.StoreMgr StoreMgr}</b>.
     * <p><b>Note</b>: if a (deprecated) <tt>{@link #id}</tt> is specified it will supersede the <tt>storeId</tt>
     * assignment.</p>
     */
    /**
     * @cfg {String} url If a <tt>{@link #proxy}</tt> is not specified the <tt>url</tt> will be used to
     * implicitly configure a {@link Ext.data.HttpProxy HttpProxy} if an <tt>url</tt> is specified.
     * Typically this option, or the <code>{@link #data}</code> option will be specified.
     */
    /**
     * @cfg {Boolean/Object} autoLoad If <tt>{@link #data}</tt> is not specified, and if <tt>autoLoad</tt>
     * is <tt>true</tt> or an <tt>Object</tt>, this store's {@link #load} method is automatically called
     * after creation. If the value of <tt>autoLoad</tt> is an <tt>Object</tt>, this <tt>Object</tt> will
     * be passed to the store's {@link #load} method.
     */
    /**
     * @cfg {Ext.data.DataProxy} proxy The {@link Ext.data.DataProxy DataProxy} object which provides
     * access to a data object.  See <code>{@link #url}</code>.
     */
    /**
     * @cfg {Array} data An inline data object readable by the <code>{@link #reader}</code>.
     * Typically this option, or the <code>{@link #url}</code> option will be specified.
     */
    /**
     * @cfg {Ext.data.DataReader} reader The {@link Ext.data.DataReader Reader} object which processes the
     * data object and returns an Array of {@link Ext.data.Record} objects which are cached keyed by their
     * <b><tt>{@link Ext.data.Record#id id}</tt></b> property.
     */
    /**
     * @cfg {Ext.data.DataWriter} writer
     * <p>The {@link Ext.data.DataWriter Writer} object which processes a record object for being written
     * to the server-side database.</p>
     * <br><p>When a writer is installed into a Store the {@link #add}, {@link #remove}, and {@link #update}
     * events on the store are monitored in order to remotely {@link #createRecords create records},
     * {@link #destroyRecord destroy records}, or {@link #updateRecord update records}.</p>
     * <br><p>The proxy for this store will relay any {@link #writexception} events to this store.</p>
     * <br><p>Sample implementation:
     * <pre><code>
var writer = new {@link Ext.data.JsonWriter}({
    encode: true,
    writeAllFields: true // write all fields, not just those that changed
});

// Typical Store collecting the Proxy, Reader and Writer together.
var store = new Ext.data.Store({
    storeId: 'user',
    root: 'records',
    proxy: proxy,
    reader: reader,
    writer: writer,     // <-- plug a DataWriter into the store just as you would a Reader
    paramsAsHash: true,
    autoSave: false    // <-- false to delay executing create, update, destroy requests
                        //     until specifically told to do so.
});
     * </code></pre></p>
     */
    writer : undefined,
    /**
     * @cfg {Object} baseParams
     * <p>An object containing properties which are to be sent as parameters
     * for <i>every</i> HTTP request.</p>
     * <p>Parameters are encoded as standard HTTP parameters using {@link Ext#urlEncode}.</p>
     * <p><b>Note</b>: <code>baseParams</code> may be superseded by any <code>params</code>
     * specified in a <code>{@link #load}</code> request, see <code>{@link #load}</code>
     * for more details.</p>
     * This property may be modified after creation using the <code>{@link #setBaseParam}</code>
     * method.
     */
    /**
     * @cfg {Object} sortInfo A config object to specify the sort order in the request of a Store's
     * {@link #load} operation.  Note that for local sorting, the <tt>direction</tt> property is
     * case-sensitive. See also {@link #remoteSort} and {@link #paramNames}.
     * For example:<pre><code>
sortInfo: {
    field: 'fieldName',
    direction: 'ASC' // or 'DESC' (case sensitive for local sorting)
}
</code></pre>
     */
    /**
     * @cfg {boolean} remoteSort <tt>true</tt> if sorting is to be handled by requesting the <tt>{@link #proxy Proxy}</tt>
     * to provide a refreshed version of the data object in sorted order, as opposed to sorting the Record cache
     * in place (defaults to <tt>false</tt>).
     * <p>If <tt>remoteSort</tt> is <tt>true</tt>, then clicking on a {@link Ext.grid.Column Grid Column}'s
     * {@link Ext.grid.Column#header header} causes the current page to be requested from the server appending
     * the following two parameters to the <b><tt>{@link #load params}</tt></b>:<div class="mdetail-params"><ul>
     * <li><b><tt>sort</tt></b> : String<p class="sub-desc">The <tt>name</tt> (as specified in the Record's
     * {@link Ext.data.Field Field definition}) of the field to sort on.</p></li>
     * <li><b><tt>dir</tt></b> : String<p class="sub-desc">The direction of the sort, 'ASC' or 'DESC' (case-sensitive).</p></li>
     * </ul></div></p>
     */
    remoteSort : false,

    /**
     * @cfg {Boolean} autoDestroy <tt>true</tt> to destroy the store when the component the store is bound
     * to is destroyed (defaults to <tt>false</tt>).
     * <p><b>Note</b>: this should be set to true when using stores that are bound to only 1 component.</p>
     */
    autoDestroy : false,

    /**
     * @cfg {Boolean} pruneModifiedRecords <tt>true</tt> to clear all modified record information each time
     * the store is loaded or when a record is removed (defaults to <tt>false</tt>). See {@link #getModifiedRecords}
     * for the accessor method to retrieve the modified records.
     */
    pruneModifiedRecords : false,

    /**
     * Contains the last options object used as the parameter to the {@link #load} method. See {@link #load}
     * for the details of what this may contain. This may be useful for accessing any params which were used
     * to load the current Record cache.
     * @property
     */
    lastOptions : null,

    /**
     * @cfg {Boolean} autoSave
     * <p>Defaults to <tt>true</tt> causing the store to automatically {@link #save} records to
     * the server when a record is modified (ie: becomes 'dirty'). Specify <tt>false</tt> to manually call {@link #save}
     * to send all modifiedRecords to the server.</p>
     * <br><p><b>Note</b>: each CRUD action will be sent as a separate request.</p>
     */
    autoSave : true,

    /**
     * @cfg {Boolean} batch
     * <p>Defaults to <tt>true</tt> (unless <code>{@link #restful}:true</code>). Multiple
     * requests for each CRUD action (CREATE, READ, UPDATE and DESTROY) will be combined
     * and sent as one transaction. Only applies when <code>{@link #autoSave}</code> is set
     * to <tt>false</tt>.</p>
     * <br><p>If Store is RESTful, the DataProxy is also RESTful, and a unique transaction is
     * generated for each record.</p>
     */
    batch : true,

    /**
     * @cfg {Boolean} restful
     * Defaults to <tt>false</tt>.  Set to <tt>true</tt> to have the Store and the set
     * Proxy operate in a RESTful manner. The store will automatically generate GET, POST,
     * PUT and DELETE requests to the server. The HTTP method used for any given CRUD
     * action is described in {@link Ext.data.Api#restActions}.  For additional information
     * see {@link Ext.data.DataProxy#restful}.
     * <p><b>Note</b>: if <code>{@link #restful}:true</code> <code>batch</code> will
     * internally be set to <tt>false</tt>.</p>
     */
    restful: false,

    /**
     * @cfg {Object} paramNames
     * <p>An object containing properties which specify the names of the paging and
     * sorting parameters passed to remote servers when loading blocks of data. By default, this
     * object takes the following form:</p><pre><code>
{
    start : 'start',  // The parameter name which specifies the start row
    limit : 'limit',  // The parameter name which specifies number of rows to return
    sort : 'sort',    // The parameter name which specifies the column to sort on
    dir : 'dir'       // The parameter name which specifies the sort direction
}
</code></pre>
     * <p>The server must produce the requested data block upon receipt of these parameter names.
     * If different parameter names are required, this property can be overriden using a configuration
     * property.</p>
     * <p>A {@link Ext.PagingToolbar PagingToolbar} bound to this Store uses this property to determine
     * the parameter names to use in its {@link #load requests}.
     */
    paramNames : undefined,

    /**
     * @cfg {Object} defaultParamNames
     * Provides the default values for the {@link #paramNames} property. To globally modify the parameters
     * for all stores, this object should be changed on the store prototype.
     */
    defaultParamNames : {
        start : 'start',
        limit : 'limit',
        sort : 'sort',
        dir : 'dir'
    },

    isDestroyed: false,
    hasMultiSort: false,

    // private
    batchKey : '_ext_batch_',

    constructor : function(config){
        /**
         * @property hasMultiSort
         * @type Boolean
         * True if this store is currently sorted by more than one field/direction combination.
         */

        /**
         * @property isDestroyed
         * @type Boolean
         * True if the store has been destroyed already. Read only
         */

        this.data = new Ext.util.MixedCollection(false);
        this.data.getKey = function(o){
            return o.id;
        };


        // temporary removed-records cache
        this.removed = [];

        if(config && config.data){
            this.inlineData = config.data;
            delete config.data;
        }

        Ext.apply(this, config);

        /**
         * See the <code>{@link #baseParams corresponding configuration option}</code>
         * for a description of this property.
         * To modify this property see <code>{@link #setBaseParam}</code>.
         * @property
         */
        this.baseParams = Ext.isObject(this.baseParams) ? this.baseParams : {};

        this.paramNames = Ext.applyIf(this.paramNames || {}, this.defaultParamNames);

        if((this.url || this.api) && !this.proxy){
            this.proxy = new Ext.data.HttpProxy({url: this.url, api: this.api});
        }
        // If Store is RESTful, so too is the DataProxy
        if (this.restful === true && this.proxy) {
            // When operating RESTfully, a unique transaction is generated for each record.
            // TODO might want to allow implemention of faux REST where batch is possible using RESTful routes only.
            this.batch = false;
            Ext.data.Api.restify(this.proxy);
        }

        if(this.reader){ // reader passed
            if(!this.recordType){
                this.recordType = this.reader.recordType;
            }
            if(this.reader.onMetaChange){
                this.reader.onMetaChange = this.reader.onMetaChange.createSequence(this.onMetaChange, this);
            }
            if (this.writer) { // writer passed
                if (this.writer instanceof(Ext.data.DataWriter) === false) {    // <-- config-object instead of instance.
                    this.writer = this.buildWriter(this.writer);
                }
                this.writer.meta = this.reader.meta;
                this.pruneModifiedRecords = true;
            }
        }

        /**
         * The {@link Ext.data.Record Record} constructor as supplied to (or created by) the
         * {@link Ext.data.DataReader Reader}. Read-only.
         * <p>If the Reader was constructed by passing in an Array of {@link Ext.data.Field} definition objects,
         * instead of a Record constructor, it will implicitly create a Record constructor from that Array (see
         * {@link Ext.data.Record}.{@link Ext.data.Record#create create} for additional details).</p>
         * <p>This property may be used to create new Records of the type held in this Store, for example:</p><pre><code>
    // create the data store
    var store = new Ext.data.ArrayStore({
        autoDestroy: true,
        fields: [
           {name: 'company'},
           {name: 'price', type: 'float'},
           {name: 'change', type: 'float'},
           {name: 'pctChange', type: 'float'},
           {name: 'lastChange', type: 'date', dateFormat: 'n/j h:ia'}
        ]
    });
    store.loadData(myData);

    // create the Grid
    var grid = new Ext.grid.EditorGridPanel({
        store: store,
        colModel: new Ext.grid.ColumnModel({
            columns: [
                {id:'company', header: 'Company', width: 160, dataIndex: 'company'},
                {header: 'Price', renderer: 'usMoney', dataIndex: 'price'},
                {header: 'Change', renderer: change, dataIndex: 'change'},
                {header: '% Change', renderer: pctChange, dataIndex: 'pctChange'},
                {header: 'Last Updated', width: 85,
                    renderer: Ext.util.Format.dateRenderer('m/d/Y'),
                    dataIndex: 'lastChange'}
            ],
            defaults: {
                sortable: true,
                width: 75
            }
        }),
        autoExpandColumn: 'company', // match the id specified in the column model
        height:350,
        width:600,
        title:'Array Grid',
        tbar: [{
            text: 'Add Record',
            handler : function(){
                var defaultData = {
                    change: 0,
                    company: 'New Company',
                    lastChange: (new Date()).clearTime(),
                    pctChange: 0,
                    price: 10
                };
                var recId = 3; // provide unique id
                var p = new store.recordType(defaultData, recId); // create new record
                grid.stopEditing();
                store.{@link #insert}(0, p); // insert a new record into the store (also see {@link #add})
                grid.startEditing(0, 0);
            }
        }]
    });
         * </code></pre>
         * @property recordType
         * @type Function
         */

        if(this.recordType){
            /**
             * A {@link Ext.util.MixedCollection MixedCollection} containing the defined {@link Ext.data.Field Field}s
             * for the {@link Ext.data.Record Records} stored in this Store. Read-only.
             * @property fields
             * @type Ext.util.MixedCollection
             */
            this.fields = this.recordType.prototype.fields;
        }
        this.modified = [];

        this.addEvents(
            /**
             * @event datachanged
             * Fires when the data cache has changed in a bulk manner (e.g., it has been sorted, filtered, etc.) and a
             * widget that is using this Store as a Record cache should refresh its view.
             * @param {Store} this
             */
            'datachanged',
            /**
             * @event metachange
             * Fires when this store's reader provides new metadata (fields). This is currently only supported for JsonReaders.
             * @param {Store} this
             * @param {Object} meta The JSON metadata
             */
            'metachange',
            /**
             * @event add
             * Fires when Records have been {@link #add}ed to the Store
             * @param {Store} this
             * @param {Ext.data.Record[]} records The array of Records added
             * @param {Number} index The index at which the record(s) were added
             */
            'add',
            /**
             * @event remove
             * Fires when a Record has been {@link #remove}d from the Store
             * @param {Store} this
             * @param {Ext.data.Record} record The Record that was removed
             * @param {Number} index The index at which the record was removed
             */
            'remove',
            /**
             * @event update
             * Fires when a Record has been updated
             * @param {Store} this
             * @param {Ext.data.Record} record The Record that was updated
             * @param {String} operation The update operation being performed.  Value may be one of:
             * <pre><code>
     Ext.data.Record.EDIT
     Ext.data.Record.REJECT
     Ext.data.Record.COMMIT
             * </code></pre>
             */
            'update',
            /**
             * @event clear
             * Fires when the data cache has been cleared.
             * @param {Store} this
             * @param {Record[]} records The records that were cleared.
             */
            'clear',
            /**
             * @event exception
             * <p>Fires if an exception occurs in the Proxy during a remote request.
             * This event is relayed through the corresponding {@link Ext.data.DataProxy}.
             * See {@link Ext.data.DataProxy}.{@link Ext.data.DataProxy#exception exception}
             * for additional details.
             * @param {misc} misc See {@link Ext.data.DataProxy}.{@link Ext.data.DataProxy#exception exception}
             * for description.
             */
            'exception',
            /**
             * @event beforeload
             * Fires before a request is made for a new data object.  If the beforeload handler returns
             * <tt>false</tt> the {@link #load} action will be canceled.
             * @param {Store} this
             * @param {Object} options The loading options that were specified (see {@link #load} for details)
             */
            'beforeload',
            /**
             * @event load
             * Fires after a new set of Records has been loaded.
             * @param {Store} this
             * @param {Ext.data.Record[]} records The Records that were loaded
             * @param {Object} options The loading options that were specified (see {@link #load} for details)
             */
            'load',
            /**
             * @event loadexception
             * <p>This event is <b>deprecated</b> in favor of the catch-all <b><code>{@link #exception}</code></b>
             * event instead.</p>
             * <p>This event is relayed through the corresponding {@link Ext.data.DataProxy}.
             * See {@link Ext.data.DataProxy}.{@link Ext.data.DataProxy#loadexception loadexception}
             * for additional details.
             * @param {misc} misc See {@link Ext.data.DataProxy}.{@link Ext.data.DataProxy#loadexception loadexception}
             * for description.
             */
            'loadexception',
            /**
             * @event beforewrite
             * @param {Ext.data.Store} store
             * @param {String} action [Ext.data.Api.actions.create|update|destroy]
             * @param {Record/Record[]} rs The Record(s) being written.
             * @param {Object} options The loading options that were specified. Edit <code>options.params</code> to add Http parameters to the request.  (see {@link #save} for details)
             * @param {Object} arg The callback's arg object passed to the {@link #request} function
             */
            'beforewrite',
            /**
             * @event write
             * Fires if the server returns 200 after an Ext.data.Api.actions CRUD action.
             * Success of the action is determined in the <code>result['successProperty']</code>property (<b>NOTE</b> for RESTful stores,
             * a simple 20x response is sufficient for the actions "destroy" and "update".  The "create" action should should return 200 along with a database pk).
             * @param {Ext.data.Store} store
             * @param {String} action [Ext.data.Api.actions.create|update|destroy]
             * @param {Object} result The 'data' picked-out out of the response for convenience.
             * @param {Ext.Direct.Transaction} res
             * @param {Record/Record[]} rs Store's records, the subject(s) of the write-action
             */
            'write',
            /**
             * @event beforesave
             * Fires before a save action is called. A save encompasses destroying records, updating records and creating records.
             * @param {Ext.data.Store} store
             * @param {Object} data An object containing the data that is to be saved. The object will contain a key for each appropriate action,
             * with an array of records for each action.
             */
            'beforesave',
            /**
             * @event save
             * Fires after a save is completed. A save encompasses destroying records, updating records and creating records.
             * @param {Ext.data.Store} store
             * @param {Number} batch The identifier for the batch that was saved.
             * @param {Object} data An object containing the data that is to be saved. The object will contain a key for each appropriate action,
             * with an array of records for each action.
             */
            'save'

        );

        if(this.proxy){
            // TODO remove deprecated loadexception with ext-3.0.1
            this.relayEvents(this.proxy,  ['loadexception', 'exception']);
        }
        // With a writer set for the Store, we want to listen to add/remove events to remotely create/destroy records.
        if (this.writer) {
            this.on({
                scope: this,
                add: this.createRecords,
                remove: this.destroyRecord,
                update: this.updateRecord,
                clear: this.onClear
            });
        }

        this.sortToggle = {};
        if(this.sortField){
            this.setDefaultSort(this.sortField, this.sortDir);
        }else if(this.sortInfo){
            this.setDefaultSort(this.sortInfo.field, this.sortInfo.direction);
        }

        Ext.data.Store.superclass.constructor.call(this);

        if(this.id){
            this.storeId = this.id;
            delete this.id;
        }
        if(this.storeId){
            Ext.StoreMgr.register(this);
        }
        if(this.inlineData){
            this.loadData(this.inlineData);
            delete this.inlineData;
        }else if(this.autoLoad){
            this.load.defer(10, this, [
                typeof this.autoLoad == 'object' ?
                    this.autoLoad : undefined]);
        }
        // used internally to uniquely identify a batch
        this.batchCounter = 0;
        this.batches = {};
    },

    /**
     * builds a DataWriter instance when Store constructor is provided with a writer config-object instead of an instace.
     * @param {Object} config Writer configuration
     * @return {Ext.data.DataWriter}
     * @private
     */
    buildWriter : function(config) {
        var klass = undefined,
            type = (config.format || 'json').toLowerCase();
        switch (type) {
            case 'json':
                klass = Ext.data.JsonWriter;
                break;
            case 'xml':
                klass = Ext.data.XmlWriter;
                break;
            default:
                klass = Ext.data.JsonWriter;
        }
        return new klass(config);
    },

    /**
     * Destroys the store.
     */
    destroy : function(){
        if(!this.isDestroyed){
            if(this.storeId){
                Ext.StoreMgr.unregister(this);
            }
            this.clearData();
            this.data = null;
            Ext.destroy(this.proxy);
            this.reader = this.writer = null;
            this.purgeListeners();
            this.isDestroyed = true;
        }
    },

    /**
     * Add Records to the Store and fires the {@link #add} event.  To add Records
     * to the store from a remote source use <code>{@link #load}({add:true})</code>.
     * See also <code>{@link #recordType}</code> and <code>{@link #insert}</code>.
     * @param {Ext.data.Record[]} records An Array of Ext.data.Record objects
     * to add to the cache. See {@link #recordType}.
     */
    add : function(records) {
        var i, len, record, index;

        records = [].concat(records);
        if (records.length < 1) {
            return;
        }

        for (i = 0, len = records.length; i < len; i++) {
            record = records[i];

            record.join(this);

            if (record.dirty || record.phantom) {
                this.modified.push(record);
            }
        }

        index = this.data.length;
        this.data.addAll(records);

        if (this.snapshot) {
            this.snapshot.addAll(records);
        }

        this.fireEvent('add', this, records, index);
    },

    /**
     * (Local sort only) Inserts the passed Record into the Store at the index where it
     * should go based on the current sort information.
     * @param {Ext.data.Record} record
     */
    addSorted : function(record){
        var index = this.findInsertIndex(record);
        this.insert(index, record);
    },

    /**
     * @private
     * Update a record within the store with a new reference
     */
    doUpdate: function(rec){
        var id = rec.id;
        // unjoin the old record
        this.getById(id).join(null);

        this.data.replace(id, rec);
        if (this.snapshot) {
            this.snapshot.replace(id, rec);
        }
        rec.join(this);
        this.fireEvent('update', this, rec, Ext.data.Record.COMMIT);
    },

    /**
     * Remove Records from the Store and fires the {@link #remove} event.
     * @param {Ext.data.Record/Ext.data.Record[]} record The record object or array of records to remove from the cache.
     */
    remove : function(record){
        if(Ext.isArray(record)){
            Ext.each(record, function(r){
                this.remove(r);
            }, this);
            return;
        }
        var index = this.data.indexOf(record);
        if(index > -1){
            record.join(null);
            this.data.removeAt(index);
        }
        if(this.pruneModifiedRecords){
            this.modified.remove(record);
        }
        if(this.snapshot){
            this.snapshot.remove(record);
        }
        if(index > -1){
            this.fireEvent('remove', this, record, index);
        }
    },

    /**
     * Remove a Record from the Store at the specified index. Fires the {@link #remove} event.
     * @param {Number} index The index of the record to remove.
     */
    removeAt : function(index){
        this.remove(this.getAt(index));
    },

    /**
     * Remove all Records from the Store and fires the {@link #clear} event.
     * @param {Boolean} silent [false] Defaults to <tt>false</tt>.  Set <tt>true</tt> to not fire clear event.
     */
    removeAll : function(silent){
        var items = [];
        this.each(function(rec){
            items.push(rec);
        });
        this.clearData();
        if(this.snapshot){
            this.snapshot.clear();
        }
        if(this.pruneModifiedRecords){
            this.modified = [];
        }
        if (silent !== true) {  // <-- prevents write-actions when we just want to clear a store.
            this.fireEvent('clear', this, items);
        }
    },

    // private
    onClear: function(store, records){
        Ext.each(records, function(rec, index){
            this.destroyRecord(this, rec, index);
        }, this);
    },

    /**
     * Inserts Records into the Store at the given index and fires the {@link #add} event.
     * See also <code>{@link #add}</code> and <code>{@link #addSorted}</code>.
     * @param {Number} index The start index at which to insert the passed Records.
     * @param {Ext.data.Record[]} records An Array of Ext.data.Record objects to add to the cache.
     */
    insert : function(index, records) {
        var i, len, record;

        records = [].concat(records);
        for (i = 0, len = records.length; i < len; i++) {
            record = records[i];

            this.data.insert(index + i, record);
            record.join(this);

            if (record.dirty || record.phantom) {
                this.modified.push(record);
            }
        }

        if (this.snapshot) {
            this.snapshot.addAll(records);
        }

        this.fireEvent('add', this, records, index);
    },

    /**
     * Get the index within the cache of the passed Record.
     * @param {Ext.data.Record} record The Ext.data.Record object to find.
     * @return {Number} The index of the passed Record. Returns -1 if not found.
     */
    indexOf : function(record){
        return this.data.indexOf(record);
    },

    /**
     * Get the index within the cache of the Record with the passed id.
     * @param {String} id The id of the Record to find.
     * @return {Number} The index of the Record. Returns -1 if not found.
     */
    indexOfId : function(id){
        return this.data.indexOfKey(id);
    },

    /**
     * Get the Record with the specified id.
     * @param {String} id The id of the Record to find.
     * @return {Ext.data.Record} The Record with the passed id. Returns undefined if not found.
     */
    getById : function(id){
        return (this.snapshot || this.data).key(id);
    },

    /**
     * Get the Record at the specified index.
     * @param {Number} index The index of the Record to find.
     * @return {Ext.data.Record} The Record at the passed index. Returns undefined if not found.
     */
    getAt : function(index){
        return this.data.itemAt(index);
    },

    /**
     * Returns a range of Records between specified indices.
     * @param {Number} startIndex (optional) The starting index (defaults to 0)
     * @param {Number} endIndex (optional) The ending index (defaults to the last Record in the Store)
     * @return {Ext.data.Record[]} An array of Records
     */
    getRange : function(start, end){
        return this.data.getRange(start, end);
    },

    // private
    storeOptions : function(o){
        o = Ext.apply({}, o);
        delete o.callback;
        delete o.scope;
        this.lastOptions = o;
    },

    // private
    clearData: function(){
        this.data.each(function(rec) {
            rec.join(null);
        });
        this.data.clear();
    },

    /**
     * <p>Loads the Record cache from the configured <tt>{@link #proxy}</tt> using the configured <tt>{@link #reader}</tt>.</p>
     * <br><p>Notes:</p><div class="mdetail-params"><ul>
     * <li><b><u>Important</u></b>: loading is asynchronous! This call will return before the new data has been
     * loaded. To perform any post-processing where information from the load call is required, specify
     * the <tt>callback</tt> function to be called, or use a {@link Ext.util.Observable#listeners a 'load' event handler}.</li>
     * <li>If using {@link Ext.PagingToolbar remote paging}, the first load call must specify the <tt>start</tt> and <tt>limit</tt>
     * properties in the <code>options.params</code> property to establish the initial position within the
     * dataset, and the number of Records to cache on each read from the Proxy.</li>
     * <li>If using {@link #remoteSort remote sorting}, the configured <code>{@link #sortInfo}</code>
     * will be automatically included with the posted parameters according to the specified
     * <code>{@link #paramNames}</code>.</li>
     * </ul></div>
     * @param {Object} options An object containing properties which control loading options:<ul>
     * <li><b><tt>params</tt></b> :Object<div class="sub-desc"><p>An object containing properties to pass as HTTP
     * parameters to a remote data source. <b>Note</b>: <code>params</code> will override any
     * <code>{@link #baseParams}</code> of the same name.</p>
     * <p>Parameters are encoded as standard HTTP parameters using {@link Ext#urlEncode}.</p></div></li>
     * <li><b>callback</b> : Function<div class="sub-desc"><p>A function to be called after the Records
     * have been loaded. The callback is called after the load event is fired, and is passed the following arguments:<ul>
     * <li>r : Ext.data.Record[] An Array of Records loaded.</li>
     * <li>options : Options object from the load call.</li>
     * <li>success : Boolean success indicator.</li></ul></p></div></li>
     * <li><b>scope</b> : Object<div class="sub-desc"><p>Scope with which to call the callback (defaults
     * to the Store object)</p></div></li>
     * <li><b>add</b> : Boolean<div class="sub-desc"><p>Indicator to append loaded records rather than
     * replace the current cache.  <b>Note</b>: see note for <tt>{@link #loadData}</tt></p></div></li>
     * </ul>
     * @return {Boolean} If the <i>developer</i> provided <tt>{@link #beforeload}</tt> event handler returns
     * <tt>false</tt>, the load call will abort and will return <tt>false</tt>; otherwise will return <tt>true</tt>.
     */
    load : function(options) {
        options = Ext.apply({}, options);
        this.storeOptions(options);
        if(this.sortInfo && this.remoteSort){
            var pn = this.paramNames;
            options.params = Ext.apply({}, options.params);
            options.params[pn.sort] = this.sortInfo.field;
            options.params[pn.dir] = this.sortInfo.direction;
        }
        try {
            return this.execute('read', null, options); // <-- null represents rs.  No rs for load actions.
        } catch(e) {
            this.handleException(e);
            return false;
        }
    },

    /**
     * updateRecord  Should not be used directly.  This method will be called automatically if a Writer is set.
     * Listens to 'update' event.
     * @param {Object} store
     * @param {Object} record
     * @param {Object} action
     * @private
     */
    updateRecord : function(store, record, action) {
        if (action == Ext.data.Record.EDIT && this.autoSave === true && (!record.phantom || (record.phantom && record.isValid()))) {
            this.save();
        }
    },

    /**
     * @private
     * Should not be used directly.  Store#add will call this automatically if a Writer is set
     * @param {Object} store
     * @param {Object} records
     * @param {Object} index
     */
    createRecords : function(store, records, index) {
        var modified = this.modified,
            length   = records.length,
            record, i;

        for (i = 0; i < length; i++) {
            record = records[i];

            if (record.phantom && record.isValid()) {
                record.markDirty();  // <-- Mark new records dirty (Ed: why?)

                if (modified.indexOf(record) == -1) {
                    modified.push(record);
                }
            }
        }
        if (this.autoSave === true) {
            this.save();
        }
    },

    /**
     * Destroys a Record.  Should not be used directly.  It's called by Store#remove if a Writer is set.
     * @param {Store} store this
     * @param {Ext.data.Record} record
     * @param {Number} index
     * @private
     */
    destroyRecord : function(store, record, index) {
        if (this.modified.indexOf(record) != -1) {  // <-- handled already if @cfg pruneModifiedRecords == true
            this.modified.remove(record);
        }
        if (!record.phantom) {
            this.removed.push(record);

            // since the record has already been removed from the store but the server request has not yet been executed,
            // must keep track of the last known index this record existed.  If a server error occurs, the record can be
            // put back into the store.  @see Store#createCallback where the record is returned when response status === false
            record.lastIndex = index;

            if (this.autoSave === true) {
                this.save();
            }
        }
    },

    /**
     * This method should generally not be used directly.  This method is called internally
     * by {@link #load}, or if a Writer is set will be called automatically when {@link #add},
     * {@link #remove}, or {@link #update} events fire.
     * @param {String} action Action name ('read', 'create', 'update', or 'destroy')
     * @param {Record/Record[]} rs
     * @param {Object} options
     * @throws Error
     * @private
     */
    execute : function(action, rs, options, /* private */ batch) {
        // blow up if action not Ext.data.CREATE, READ, UPDATE, DESTROY
        if (!Ext.data.Api.isAction(action)) {
            throw new Ext.data.Api.Error('execute', action);
        }
        // make sure options has a fresh, new params hash
        options = Ext.applyIf(options||{}, {
            params: {}
        });
        if(batch !== undefined){
            this.addToBatch(batch);
        }
        // have to separate before-events since load has a different signature than create,destroy and save events since load does not
        // include the rs (record resultset) parameter.  Capture return values from the beforeaction into doRequest flag.
        var doRequest = true;

        if (action === 'read') {
            doRequest = this.fireEvent('beforeload', this, options);
            Ext.applyIf(options.params, this.baseParams);
        }
        else {
            // if Writer is configured as listful, force single-record rs to be [{}] instead of {}
            // TODO Move listful rendering into DataWriter where the @cfg is defined.  Should be easy now.
            if (this.writer.listful === true && this.restful !== true) {
                rs = (Ext.isArray(rs)) ? rs : [rs];
            }
            // if rs has just a single record, shift it off so that Writer writes data as '{}' rather than '[{}]'
            else if (Ext.isArray(rs) && rs.length == 1) {
                rs = rs.shift();
            }
            // Write the action to options.params
            if ((doRequest = this.fireEvent('beforewrite', this, action, rs, options)) !== false) {
                this.writer.apply(options.params, this.baseParams, action, rs);
            }
        }
        if (doRequest !== false) {
            // Send request to proxy.
            if (this.writer && this.proxy.url && !this.proxy.restful && !Ext.data.Api.hasUniqueUrl(this.proxy, action)) {
                options.params.xaction = action;    // <-- really old, probaby unecessary.
            }
            // Note:  Up until this point we've been dealing with 'action' as a key from Ext.data.Api.actions.
            // We'll flip it now and send the value into DataProxy#request, since it's the value which maps to
            // the user's configured DataProxy#api
            // TODO Refactor all Proxies to accept an instance of Ext.data.Request (not yet defined) instead of this looooooong list
            // of params.  This method is an artifact from Ext2.
            this.proxy.request(Ext.data.Api.actions[action], rs, options.params, this.reader, this.createCallback(action, rs, batch), this, options);
        }
        return doRequest;
    },

    /**
     * Saves all pending changes to the store.  If the commensurate Ext.data.Api.actions action is not configured, then
     * the configured <code>{@link #url}</code> will be used.
     * <pre>
     * change            url
     * ---------------   --------------------
     * removed records   Ext.data.Api.actions.destroy
     * phantom records   Ext.data.Api.actions.create
     * {@link #getModifiedRecords modified records}  Ext.data.Api.actions.update
     * </pre>
     * @TODO:  Create extensions of Error class and send associated Record with thrown exceptions.
     * e.g.:  Ext.data.DataReader.Error or Ext.data.Error or Ext.data.DataProxy.Error, etc.
     * @return {Number} batch Returns a number to uniquely identify the "batch" of saves occurring. -1 will be returned
     * if there are no items to save or the save was cancelled.
     */
    save : function() {
        if (!this.writer) {
            throw new Ext.data.Store.Error('writer-undefined');
        }

        var queue = [],
            len,
            trans,
            batch,
            data = {},
            i;
        // DESTROY:  First check for removed records.  Records in this.removed are guaranteed non-phantoms.  @see Store#remove
        if(this.removed.length){
            queue.push(['destroy', this.removed]);
        }

        // Check for modified records. Use a copy so Store#rejectChanges will work if server returns error.
        var rs = [].concat(this.getModifiedRecords());
        if(rs.length){
            // CREATE:  Next check for phantoms within rs.  splice-off and execute create.
            var phantoms = [];
            for(i = rs.length-1; i >= 0; i--){
                if(rs[i].phantom === true){
                    var rec = rs.splice(i, 1).shift();
                    if(rec.isValid()){
                        phantoms.push(rec);
                    }
                }else if(!rs[i].isValid()){ // <-- while we're here, splice-off any !isValid real records
                    rs.splice(i,1);
                }
            }
            // If we have valid phantoms, create them...
            if(phantoms.length){
                queue.push(['create', phantoms]);
            }

            // UPDATE:  And finally, if we're still here after splicing-off phantoms and !isValid real records, update the rest...
            if(rs.length){
                queue.push(['update', rs]);
            }
        }
        len = queue.length;
        if(len){
            batch = ++this.batchCounter;
            for(i = 0; i < len; ++i){
                trans = queue[i];
                data[trans[0]] = trans[1];
            }
            if(this.fireEvent('beforesave', this, data) !== false){
                for(i = 0; i < len; ++i){
                    trans = queue[i];
                    this.doTransaction(trans[0], trans[1], batch);
                }
                return batch;
            }
        }
        return -1;
    },

    // private.  Simply wraps call to Store#execute in try/catch.  Defers to Store#handleException on error.  Loops if batch: false
    doTransaction : function(action, rs, batch) {
        function transaction(records) {
            try{
                this.execute(action, records, undefined, batch);
            }catch (e){
                this.handleException(e);
            }
        }
        if(this.batch === false){
            for(var i = 0, len = rs.length; i < len; i++){
                transaction.call(this, rs[i]);
            }
        }else{
            transaction.call(this, rs);
        }
    },

    // private
    addToBatch : function(batch){
        var b = this.batches,
            key = this.batchKey + batch,
            o = b[key];

        if(!o){
            b[key] = o = {
                id: batch,
                count: 0,
                data: {}
            };
        }
        ++o.count;
    },

    removeFromBatch : function(batch, action, data){
        var b = this.batches,
            key = this.batchKey + batch,
            o = b[key],
            arr;


        if(o){
            arr = o.data[action] || [];
            o.data[action] = arr.concat(data);
            if(o.count === 1){
                data = o.data;
                delete b[key];
                this.fireEvent('save', this, batch, data);
            }else{
                --o.count;
            }
        }
    },

    // @private callback-handler for remote CRUD actions
    // Do not override -- override loadRecords, onCreateRecords, onDestroyRecords and onUpdateRecords instead.
    createCallback : function(action, rs, batch) {
        var actions = Ext.data.Api.actions;
        return (action == 'read') ? this.loadRecords : function(data, response, success) {
            // calls: onCreateRecords | onUpdateRecords | onDestroyRecords
            this['on' + Ext.util.Format.capitalize(action) + 'Records'](success, rs, [].concat(data));
            // If success === false here, exception will have been called in DataProxy
            if (success === true) {
                this.fireEvent('write', this, action, data, response, rs);
            }
            this.removeFromBatch(batch, action, data);
        };
    },

    // Clears records from modified array after an exception event.
    // NOTE:  records are left marked dirty.  Do we want to commit them even though they were not updated/realized?
    // TODO remove this method?
    clearModified : function(rs) {
        if (Ext.isArray(rs)) {
            for (var n=rs.length-1;n>=0;n--) {
                this.modified.splice(this.modified.indexOf(rs[n]), 1);
            }
        } else {
            this.modified.splice(this.modified.indexOf(rs), 1);
        }
    },

    // remap record ids in MixedCollection after records have been realized.  @see Store#onCreateRecords, @see DataReader#realize
    reMap : function(record) {
        if (Ext.isArray(record)) {
            for (var i = 0, len = record.length; i < len; i++) {
                this.reMap(record[i]);
            }
        } else {
            delete this.data.map[record._phid];
            this.data.map[record.id] = record;
            var index = this.data.keys.indexOf(record._phid);
            this.data.keys.splice(index, 1, record.id);
            delete record._phid;
        }
    },

    // @protected onCreateRecord proxy callback for create action
    onCreateRecords : function(success, rs, data) {
        if (success === true) {
            try {
                this.reader.realize(rs, data);
            }
            catch (e) {
                this.handleException(e);
                if (Ext.isArray(rs)) {
                    // Recurse to run back into the try {}.  DataReader#realize splices-off the rs until empty.
                    this.onCreateRecords(success, rs, data);
                }
            }
        }
    },

    // @protected, onUpdateRecords proxy callback for update action
    onUpdateRecords : function(success, rs, data) {
        if (success === true) {
            try {
                this.reader.update(rs, data);
            } catch (e) {
                this.handleException(e);
                if (Ext.isArray(rs)) {
                    // Recurse to run back into the try {}.  DataReader#update splices-off the rs until empty.
                    this.onUpdateRecords(success, rs, data);
                }
            }
        }
    },

    // @protected onDestroyRecords proxy callback for destroy action
    onDestroyRecords : function(success, rs, data) {
        // splice each rec out of this.removed
        rs = (rs instanceof Ext.data.Record) ? [rs] : [].concat(rs);
        for (var i=0,len=rs.length;i<len;i++) {
            this.removed.splice(this.removed.indexOf(rs[i]), 1);
        }
        if (success === false) {
            // put records back into store if remote destroy fails.
            // @TODO: Might want to let developer decide.
            for (i=rs.length-1;i>=0;i--) {
                this.insert(rs[i].lastIndex, rs[i]);    // <-- lastIndex set in Store#destroyRecord
            }
        }
    },

    // protected handleException.  Possibly temporary until Ext framework has an exception-handler.
    handleException : function(e) {
        // @see core/Error.js
        Ext.handleError(e);
    },

    /**
     * <p>Reloads the Record cache from the configured Proxy using the configured
     * {@link Ext.data.Reader Reader} and the options from the last load operation
     * performed.</p>
     * <p><b>Note</b>: see the Important note in {@link #load}.</p>
     * @param {Object} options <p>(optional) An <tt>Object</tt> containing
     * {@link #load loading options} which may override the {@link #lastOptions options}
     * used in the last {@link #load} operation. See {@link #load} for details
     * (defaults to <tt>null</tt>, in which case the {@link #lastOptions} are
     * used).</p>
     * <br><p>To add new params to the existing params:</p><pre><code>
lastOptions = myStore.lastOptions;
Ext.apply(lastOptions.params, {
    myNewParam: true
});
myStore.reload(lastOptions);
     * </code></pre>
     */
    reload : function(options){
        this.load(Ext.applyIf(options||{}, this.lastOptions));
    },

    // private
    // Called as a callback by the Reader during a load operation.
    loadRecords : function(o, options, success){
        var i, len;

        if (this.isDestroyed === true) {
            return;
        }
        if(!o || success === false){
            if(success !== false){
                this.fireEvent('load', this, [], options);
            }
            if(options.callback){
                options.callback.call(options.scope || this, [], options, false, o);
            }
            return;
        }
        var r = o.records, t = o.totalRecords || r.length;
        if(!options || options.add !== true){
            if(this.pruneModifiedRecords){
                this.modified = [];
            }
            for(i = 0, len = r.length; i < len; i++){
                r[i].join(this);
            }
            if(this.snapshot){
                this.data = this.snapshot;
                delete this.snapshot;
            }
            this.clearData();
            this.data.addAll(r);
            this.totalLength = t;
            this.applySort();
            this.fireEvent('datachanged', this);
        }else{
            var toAdd = [],
                rec,
                cnt = 0;
            for(i = 0, len = r.length; i < len; ++i){
                rec = r[i];
                if(this.indexOfId(rec.id) > -1){
                    this.doUpdate(rec);
                }else{
                    toAdd.push(rec);
                    ++cnt;
                }
            }
            this.totalLength = Math.max(t, this.data.length + cnt);
            this.add(toAdd);
        }
        this.fireEvent('load', this, r, options);
        if(options.callback){
            options.callback.call(options.scope || this, r, options, true);
        }
    },

    /**
     * Loads data from a passed data block and fires the {@link #load} event. A {@link Ext.data.Reader Reader}
     * which understands the format of the data must have been configured in the constructor.
     * @param {Object} data The data block from which to read the Records.  The format of the data expected
     * is dependent on the type of {@link Ext.data.Reader Reader} that is configured and should correspond to
     * that {@link Ext.data.Reader Reader}'s <tt>{@link Ext.data.Reader#readRecords}</tt> parameter.
     * @param {Boolean} append (Optional) <tt>true</tt> to append the new Records rather the default to replace
     * the existing cache.
     * <b>Note</b>: that Records in a Store are keyed by their {@link Ext.data.Record#id id}, so added Records
     * with ids which are already present in the Store will <i>replace</i> existing Records. Only Records with
     * new, unique ids will be added.
     */
    loadData : function(o, append){
        var r = this.reader.readRecords(o);
        this.loadRecords(r, {add: append}, true);
    },

    /**
     * Gets the number of cached records.
     * <p>If using paging, this may not be the total size of the dataset. If the data object
     * used by the Reader contains the dataset size, then the {@link #getTotalCount} function returns
     * the dataset size.  <b>Note</b>: see the Important note in {@link #load}.</p>
     * @return {Number} The number of Records in the Store's cache.
     */
    getCount : function(){
        return this.data.length || 0;
    },

    /**
     * Gets the total number of records in the dataset as returned by the server.
     * <p>If using paging, for this to be accurate, the data object used by the {@link #reader Reader}
     * must contain the dataset size. For remote data sources, the value for this property
     * (<tt>totalProperty</tt> for {@link Ext.data.JsonReader JsonReader},
     * <tt>totalRecords</tt> for {@link Ext.data.XmlReader XmlReader}) shall be returned by a query on the server.
     * <b>Note</b>: see the Important note in {@link #load}.</p>
     * @return {Number} The number of Records as specified in the data object passed to the Reader
     * by the Proxy.
     * <p><b>Note</b>: this value is not updated when changing the contents of the Store locally.</p>
     */
    getTotalCount : function(){
        return this.totalLength || 0;
    },

    /**
     * Returns an object describing the current sort state of this Store.
     * @return {Object} The sort state of the Store. An object with two properties:<ul>
     * <li><b>field : String</b><p class="sub-desc">The name of the field by which the Records are sorted.</p></li>
     * <li><b>direction : String</b><p class="sub-desc">The sort order, 'ASC' or 'DESC' (case-sensitive).</p></li>
     * </ul>
     * See <tt>{@link #sortInfo}</tt> for additional details.
     */
    getSortState : function(){
        return this.sortInfo;
    },

    /**
     * @private
     * Invokes sortData if we have sortInfo to sort on and are not sorting remotely
     */
    applySort : function(){
        if ((this.sortInfo || this.multiSortInfo) && !this.remoteSort) {
            this.sortData();
        }
    },

    /**
     * @private
     * Performs the actual sorting of data. This checks to see if we currently have a multi sort or not. It applies
     * each sorter field/direction pair in turn by building an OR'ed master sorting function and running it against
     * the full dataset
     */
    sortData : function() {
        var sortInfo  = this.hasMultiSort ? this.multiSortInfo : this.sortInfo,
            direction = sortInfo.direction || "ASC",
            sorters   = sortInfo.sorters,
            sortFns   = [];

        //if we just have a single sorter, pretend it's the first in an array
        if (!this.hasMultiSort) {
            sorters = [{direction: direction, field: sortInfo.field}];
        }

        //create a sorter function for each sorter field/direction combo
        for (var i=0, j = sorters.length; i < j; i++) {
            sortFns.push(this.createSortFunction(sorters[i].field, sorters[i].direction));
        }

        if (sortFns.length == 0) {
            return;
        }

        //the direction modifier is multiplied with the result of the sorting functions to provide overall sort direction
        //(as opposed to direction per field)
        var directionModifier = direction.toUpperCase() == "DESC" ? -1 : 1;

        //create a function which ORs each sorter together to enable multi-sort
        var fn = function(r1, r2) {
          var result = sortFns[0].call(this, r1, r2);

          //if we have more than one sorter, OR any additional sorter functions together
          if (sortFns.length > 1) {
              for (var i=1, j = sortFns.length; i < j; i++) {
                  result = result || sortFns[i].call(this, r1, r2);
              }
          }

          return directionModifier * result;
        };

        //sort the data
        this.data.sort(direction, fn);
        if (this.snapshot && this.snapshot != this.data) {
            this.snapshot.sort(direction, fn);
        }
    },

    /**
     * @private
     * Creates and returns a function which sorts an array by the given field and direction
     * @param {String} field The field to create the sorter for
     * @param {String} direction The direction to sort by (defaults to "ASC")
     * @return {Function} A function which sorts by the field/direction combination provided
     */
    createSortFunction: function(field, direction) {
        direction = direction || "ASC";
        var directionModifier = direction.toUpperCase() == "DESC" ? -1 : 1;

        var sortType = this.fields.get(field).sortType;

        //create a comparison function. Takes 2 records, returns 1 if record 1 is greater,
        //-1 if record 2 is greater or 0 if they are equal
        return function(r1, r2) {
            var v1 = sortType(r1.data[field]),
                v2 = sortType(r2.data[field]);

            return directionModifier * (v1 > v2 ? 1 : (v1 < v2 ? -1 : 0));
        };
    },

    /**
     * Sets the default sort column and order to be used by the next {@link #load} operation.
     * @param {String} fieldName The name of the field to sort by.
     * @param {String} dir (optional) The sort order, 'ASC' or 'DESC' (case-sensitive, defaults to <tt>'ASC'</tt>)
     */
    setDefaultSort : function(field, dir) {
        dir = dir ? dir.toUpperCase() : 'ASC';
        this.sortInfo = {field: field, direction: dir};
        this.sortToggle[field] = dir;
    },

    /**
     * Sort the Records.
     * If remote sorting is used, the sort is performed on the server, and the cache is reloaded. If local
     * sorting is used, the cache is sorted internally. See also {@link #remoteSort} and {@link #paramNames}.
     * This function accepts two call signatures - pass in a field name as the first argument to sort on a single
     * field, or pass in an array of sort configuration objects to sort by multiple fields.
     * Single sort example:
     * store.sort('name', 'ASC');
     * Multi sort example:
     * store.sort([
     *   {
     *     field    : 'name',
     *     direction: 'ASC'
     *   },
     *   {
     *     field    : 'salary',
     *     direction: 'DESC'
     *   }
     * ], 'ASC');
     * In this second form, the sort configs are applied in order, with later sorters sorting within earlier sorters' results.
     * For example, if two records with the same name are present they will also be sorted by salary if given the sort configs
     * above. Any number of sort configs can be added.
     * @param {String/Array} fieldName The name of the field to sort by, or an array of ordered sort configs
     * @param {String} dir (optional) The sort order, 'ASC' or 'DESC' (case-sensitive, defaults to <tt>'ASC'</tt>)
     */
    sort : function(fieldName, dir) {
        if (Ext.isArray(arguments[0])) {
            return this.multiSort.call(this, fieldName, dir);
        } else {
            return this.singleSort(fieldName, dir);
        }
    },

    /**
     * Sorts the store contents by a single field and direction. This is called internally by {@link sort} and would
     * not usually be called manually
     * @param {String} fieldName The name of the field to sort by.
     * @param {String} dir (optional) The sort order, 'ASC' or 'DESC' (case-sensitive, defaults to <tt>'ASC'</tt>)
     */
    singleSort: function(fieldName, dir) {
        var field = this.fields.get(fieldName);
        if (!field) {
            return false;
        }

        var name       = field.name,
            sortInfo   = this.sortInfo || null,
            sortToggle = this.sortToggle ? this.sortToggle[name] : null;

        if (!dir) {
            if (sortInfo && sortInfo.field == name) { // toggle sort dir
                dir = (this.sortToggle[name] || 'ASC').toggle('ASC', 'DESC');
            } else {
                dir = field.sortDir;
            }
        }

        this.sortToggle[name] = dir;
        this.sortInfo = {field: name, direction: dir};
        this.hasMultiSort = false;

        if (this.remoteSort) {
            if (!this.load(this.lastOptions)) {
                if (sortToggle) {
                    this.sortToggle[name] = sortToggle;
                }
                if (sortInfo) {
                    this.sortInfo = sortInfo;
                }
            }
        } else {
            this.applySort();
            this.fireEvent('datachanged', this);
        }
        return true;
    },

    /**
     * Sorts the contents of this store by multiple field/direction sorters. This is called internally by {@link sort}
     * and would not usually be called manually.
     * Multi sorting only currently applies to local datasets - multiple sort data is not currently sent to a proxy
     * if remoteSort is used.
     * @param {Array} sorters Array of sorter objects (field and direction)
     * @param {String} direction Overall direction to sort the ordered results by (defaults to "ASC")
     */
    multiSort: function(sorters, direction) {
        this.hasMultiSort = true;
        direction = direction || "ASC";

        //toggle sort direction
        if (this.multiSortInfo && direction == this.multiSortInfo.direction) {
            direction = direction.toggle("ASC", "DESC");
        }

        /**
         * Object containing overall sort direction and an ordered array of sorter configs used when sorting on multiple fields
         * @property multiSortInfo
         * @type Object
         */
        this.multiSortInfo = {
            sorters  : sorters,
            direction: direction
        };

        if (this.remoteSort) {
            this.singleSort(sorters[0].field, sorters[0].direction);

        } else {
            this.applySort();
            this.fireEvent('datachanged', this);
        }
    },

    /**
     * Calls the specified function for each of the {@link Ext.data.Record Records} in the cache.
     * @param {Function} fn The function to call. The {@link Ext.data.Record Record} is passed as the first parameter.
     * Returning <tt>false</tt> aborts and exits the iteration.
     * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the function is executed.
     * Defaults to the current {@link Ext.data.Record Record} in the iteration.
     */
    each : function(fn, scope){
        this.data.each(fn, scope);
    },

    /**
     * Gets all {@link Ext.data.Record records} modified since the last commit.  Modified records are
     * persisted across load operations (e.g., during paging). <b>Note</b>: deleted records are not
     * included.  See also <tt>{@link #pruneModifiedRecords}</tt> and
     * {@link Ext.data.Record}<tt>{@link Ext.data.Record#markDirty markDirty}.</tt>.
     * @return {Ext.data.Record[]} An array of {@link Ext.data.Record Records} containing outstanding
     * modifications.  To obtain modified fields within a modified record see
     *{@link Ext.data.Record}<tt>{@link Ext.data.Record#modified modified}.</tt>.
     */
    getModifiedRecords : function(){
        return this.modified;
    },

    /**
     * Sums the value of <tt>property</tt> for each {@link Ext.data.Record record} between <tt>start</tt>
     * and <tt>end</tt> and returns the result.
     * @param {String} property A field in each record
     * @param {Number} start (optional) The record index to start at (defaults to <tt>0</tt>)
     * @param {Number} end (optional) The last record index to include (defaults to length - 1)
     * @return {Number} The sum
     */
    sum : function(property, start, end){
        var rs = this.data.items, v = 0;
        start = start || 0;
        end = (end || end === 0) ? end : rs.length-1;

        for(var i = start; i <= end; i++){
            v += (rs[i].data[property] || 0);
        }
        return v;
    },

    /**
     * @private
     * Returns a filter function used to test a the given property's value. Defers most of the work to
     * Ext.util.MixedCollection's createValueMatcher function
     * @param {String} property The property to create the filter function for
     * @param {String/RegExp} value The string/regex to compare the property value to
     * @param {Boolean} anyMatch True if we don't care if the filter value is not the full value (defaults to false)
     * @param {Boolean} caseSensitive True to create a case-sensitive regex (defaults to false)
     * @param {Boolean} exactMatch True to force exact match (^ and $ characters added to the regex). Defaults to false. Ignored if anyMatch is true.
     */
    createFilterFn : function(property, value, anyMatch, caseSensitive, exactMatch){
        if(Ext.isEmpty(value, false)){
            return false;
        }
        value = this.data.createValueMatcher(value, anyMatch, caseSensitive, exactMatch);
        return function(r) {
            return value.test(r.data[property]);
        };
    },

    /**
     * @private
     * Given an array of filter functions (each with optional scope), constructs and returns a single function that returns
     * the result of all of the filters ANDed together
     * @param {Array} filters The array of filter objects (each object should contain an 'fn' and optional scope)
     * @return {Function} The multiple filter function
     */
    createMultipleFilterFn: function(filters) {
        return function(record) {
            var isMatch = true;

            for (var i=0, j = filters.length; i < j; i++) {
                var filter = filters[i],
                    fn     = filter.fn,
                    scope  = filter.scope;

                isMatch = isMatch && fn.call(scope, record);
            }

            return isMatch;
        };
    },

    /**
     * Filter the {@link Ext.data.Record records} by a specified property. Alternatively, pass an array of filter
     * options to filter by more than one property.
     * Single filter example:
     * store.filter('name', 'Ed', true, true); //finds all records containing the substring 'Ed'
     * Multiple filter example:
     * <pre><code>
     * store.filter([
     *   {
     *     property     : 'name',
     *     value        : 'Ed',
     *     anyMatch     : true, //optional, defaults to true
     *     caseSensitive: true  //optional, defaults to true
     *   },
     *
     *   //filter functions can also be passed
     *   {
     *     fn   : function(record) {
     *       return record.get('age') == 24
     *     },
     *     scope: this
     *   }
     * ]);
     * </code></pre>
     * @param {String|Array} field A field on your records, or an array containing multiple filter options
     * @param {String/RegExp} value Either a string that the field should begin with, or a RegExp to test
     * against the field.
     * @param {Boolean} anyMatch (optional) <tt>true</tt> to match any part not just the beginning
     * @param {Boolean} caseSensitive (optional) <tt>true</tt> for case sensitive comparison
     * @param {Boolean} exactMatch (optional) True to force exact match (^ and $ characters added to the regex). Defaults to false. Ignored if anyMatch is true.
     */
    filter : function(property, value, anyMatch, caseSensitive, exactMatch){
        var fn;
        //we can accept an array of filter objects, or a single filter object - normalize them here
        if (Ext.isObject(property)) {
            property = [property];
        }

        if (Ext.isArray(property)) {
            var filters = [];

            //normalize the filters passed into an array of filter functions
            for (var i=0, j = property.length; i < j; i++) {
                var filter = property[i],
                    func   = filter.fn,
                    scope  = filter.scope || this;

                //if we weren't given a filter function, construct one now
                if (!Ext.isFunction(func)) {
                    func = this.createFilterFn(filter.property, filter.value, filter.anyMatch, filter.caseSensitive, filter.exactMatch);
                }

                filters.push({fn: func, scope: scope});
            }

            fn = this.createMultipleFilterFn(filters);
        } else {
            //classic single property filter
            fn = this.createFilterFn(property, value, anyMatch, caseSensitive, exactMatch);
        }

        return fn ? this.filterBy(fn) : this.clearFilter();
    },

    /**
     * Filter by a function. The specified function will be called for each
     * Record in this Store. If the function returns <tt>true</tt> the Record is included,
     * otherwise it is filtered out.
     * @param {Function} fn The function to be called. It will be passed the following parameters:<ul>
     * <li><b>record</b> : Ext.data.Record<p class="sub-desc">The {@link Ext.data.Record record}
     * to test for filtering. Access field values using {@link Ext.data.Record#get}.</p></li>
     * <li><b>id</b> : Object<p class="sub-desc">The ID of the Record passed.</p></li>
     * </ul>
     * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the function is executed. Defaults to this Store.
     */
    filterBy : function(fn, scope){
        this.snapshot = this.snapshot || this.data;
        this.data = this.queryBy(fn, scope || this);
        this.fireEvent('datachanged', this);
    },

    /**
     * Revert to a view of the Record cache with no filtering applied.
     * @param {Boolean} suppressEvent If <tt>true</tt> the filter is cleared silently without firing the
     * {@link #datachanged} event.
     */
    clearFilter : function(suppressEvent){
        if(this.isFiltered()){
            this.data = this.snapshot;
            delete this.snapshot;
            if(suppressEvent !== true){
                this.fireEvent('datachanged', this);
            }
        }
    },

    /**
     * Returns true if this store is currently filtered
     * @return {Boolean}
     */
    isFiltered : function(){
        return !!this.snapshot && this.snapshot != this.data;
    },

    /**
     * Query the records by a specified property.
     * @param {String} field A field on your records
     * @param {String/RegExp} value Either a string that the field
     * should begin with, or a RegExp to test against the field.
     * @param {Boolean} anyMatch (optional) True to match any part not just the beginning
     * @param {Boolean} caseSensitive (optional) True for case sensitive comparison
     * @return {MixedCollection} Returns an Ext.util.MixedCollection of the matched records
     */
    query : function(property, value, anyMatch, caseSensitive){
        var fn = this.createFilterFn(property, value, anyMatch, caseSensitive);
        return fn ? this.queryBy(fn) : this.data.clone();
    },

    /**
     * Query the cached records in this Store using a filtering function. The specified function
     * will be called with each record in this Store. If the function returns <tt>true</tt> the record is
     * included in the results.
     * @param {Function} fn The function to be called. It will be passed the following parameters:<ul>
     * <li><b>record</b> : Ext.data.Record<p class="sub-desc">The {@link Ext.data.Record record}
     * to test for filtering. Access field values using {@link Ext.data.Record#get}.</p></li>
     * <li><b>id</b> : Object<p class="sub-desc">The ID of the Record passed.</p></li>
     * </ul>
     * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the function is executed. Defaults to this Store.
     * @return {MixedCollection} Returns an Ext.util.MixedCollection of the matched records
     **/
    queryBy : function(fn, scope){
        var data = this.snapshot || this.data;
        return data.filterBy(fn, scope||this);
    },

    /**
     * Finds the index of the first matching Record in this store by a specific field value.
     * @param {String} fieldName The name of the Record field to test.
     * @param {String/RegExp} value Either a string that the field value
     * should begin with, or a RegExp to test against the field.
     * @param {Number} startIndex (optional) The index to start searching at
     * @param {Boolean} anyMatch (optional) True to match any part of the string, not just the beginning
     * @param {Boolean} caseSensitive (optional) True for case sensitive comparison
     * @return {Number} The matched index or -1
     */
    find : function(property, value, start, anyMatch, caseSensitive){
        var fn = this.createFilterFn(property, value, anyMatch, caseSensitive);
        return fn ? this.data.findIndexBy(fn, null, start) : -1;
    },

    /**
     * Finds the index of the first matching Record in this store by a specific field value.
     * @param {String} fieldName The name of the Record field to test.
     * @param {Mixed} value The value to match the field against.
     * @param {Number} startIndex (optional) The index to start searching at
     * @return {Number} The matched index or -1
     */
    findExact: function(property, value, start){
        return this.data.findIndexBy(function(rec){
            return rec.get(property) === value;
        }, this, start);
    },

    /**
     * Find the index of the first matching Record in this Store by a function.
     * If the function returns <tt>true</tt> it is considered a match.
     * @param {Function} fn The function to be called. It will be passed the following parameters:<ul>
     * <li><b>record</b> : Ext.data.Record<p class="sub-desc">The {@link Ext.data.Record record}
     * to test for filtering. Access field values using {@link Ext.data.Record#get}.</p></li>
     * <li><b>id</b> : Object<p class="sub-desc">The ID of the Record passed.</p></li>
     * </ul>
     * @param {Object} scope (optional) The scope (<code>this</code> reference) in which the function is executed. Defaults to this Store.
     * @param {Number} startIndex (optional) The index to start searching at
     * @return {Number} The matched index or -1
     */
    findBy : function(fn, scope, start){
        return this.data.findIndexBy(fn, scope, start);
    },

    /**
     * Collects unique values for a particular dataIndex from this store.
     * @param {String} dataIndex The property to collect
     * @param {Boolean} allowNull (optional) Pass true to allow null, undefined or empty string values
     * @param {Boolean} bypassFilter (optional) Pass true to collect from all records, even ones which are filtered
     * @return {Array} An array of the unique values
     **/
    collect : function(dataIndex, allowNull, bypassFilter){
        var d = (bypassFilter === true && this.snapshot) ?
                this.snapshot.items : this.data.items;
        var v, sv, r = [], l = {};
        for(var i = 0, len = d.length; i < len; i++){
            v = d[i].data[dataIndex];
            sv = String(v);
            if((allowNull || !Ext.isEmpty(v)) && !l[sv]){
                l[sv] = true;
                r[r.length] = v;
            }
        }
        return r;
    },

    // private
    afterEdit : function(record){
        if(this.modified.indexOf(record) == -1){
            this.modified.push(record);
        }
        this.fireEvent('update', this, record, Ext.data.Record.EDIT);
    },

    // private
    afterReject : function(record){
        this.modified.remove(record);
        this.fireEvent('update', this, record, Ext.data.Record.REJECT);
    },

    // private
    afterCommit : function(record){
        this.modified.remove(record);
        this.fireEvent('update', this, record, Ext.data.Record.COMMIT);
    },

    /**
     * Commit all Records with {@link #getModifiedRecords outstanding changes}. To handle updates for changes,
     * subscribe to the Store's {@link #update update event}, and perform updating when the third parameter is
     * Ext.data.Record.COMMIT.
     */
    commitChanges : function(){
        var modified = this.modified.slice(0),
            length   = modified.length,
            i;

        for (i = 0; i < length; i++){
            modified[i].commit();
        }

        this.modified = [];
        this.removed  = [];
    },

    /**
     * {@link Ext.data.Record#reject Reject} outstanding changes on all {@link #getModifiedRecords modified records}.
     */
    rejectChanges : function() {
        var modified = this.modified.slice(0),
            removed  = this.removed.slice(0).reverse(),
            mLength  = modified.length,
            rLength  = removed.length,
            i;

        for (i = 0; i < mLength; i++) {
            modified[i].reject();
        }

        for (i = 0; i < rLength; i++) {
            this.insert(removed[i].lastIndex || 0, removed[i]);
            removed[i].reject();
        }

        this.modified = [];
        this.removed  = [];
    },

    // private
    onMetaChange : function(meta){
        this.recordType = this.reader.recordType;
        this.fields = this.recordType.prototype.fields;
        delete this.snapshot;
        if(this.reader.meta.sortInfo){
            this.sortInfo = this.reader.meta.sortInfo;
        }else if(this.sortInfo  && !this.fields.get(this.sortInfo.field)){
            delete this.sortInfo;
        }
        if(this.writer){
            this.writer.meta = this.reader.meta;
        }
        this.modified = [];
        this.fireEvent('metachange', this, this.reader.meta);
    },

    // private
    findInsertIndex : function(record){
        this.suspendEvents();
        var data = this.data.clone();
        this.data.add(record);
        this.applySort();
        var index = this.data.indexOf(record);
        this.data = data;
        this.resumeEvents();
        return index;
    },

    /**
     * Set the value for a property name in this store's {@link #baseParams}.  Usage:</p><pre><code>
myStore.setBaseParam('foo', {bar:3});
</code></pre>
     * @param {String} name Name of the property to assign
     * @param {Mixed} value Value to assign the <tt>name</tt>d property
     **/
    setBaseParam : function (name, value){
        this.baseParams = this.baseParams || {};
        this.baseParams[name] = value;
    }
});

Ext.reg('store', Ext.data.Store);

/**
 * @class Ext.data.Store.Error
 * @extends Ext.Error
 * Store Error extension.
 * @param {String} name
 */
Ext.data.Store.Error = Ext.extend(Ext.Error, {
    name: 'Ext.data.Store'
});
Ext.apply(Ext.data.Store.Error.prototype, {
    lang: {
        'writer-undefined' : 'Attempted to execute a write-action without a DataWriter installed.'
    }
});
