# GvaScript.Grid

ChoiceList based Grid with Pagination

### Table of contents

NAME
SYNOPSIS
DEPENDENCIES
DESTRUCTOR
DESCRIPTION
GvaScript.Grids
GvaScript.Grids.get(id)
BEHAVIOUR
Grid Navigation Behaviour
JSON Datasource
CONSTRUCTOR
id
url
options
PROPERTIES
grid_container
toolbar_container
paginatorbar_container
actionsbar_container
METHODS
clearResult
clearToolbar
clearActionButtons
clear
addActionButtons
EVENTS
onShow
onHighlight
onPing
onCancel
onEmpty
EXAMPLE
JAVASCRIPT
HTML
CSS

## NAME

GvaScript.Grid - ChoiceList based Grid with Pagination

## SYNOPSIS

      var my_url  = "/app/path/to/data/list";
      var grid_id = "my_unique_grid_id";

      var my_grid = new GvaScript.Grid(grid_id, my_url, {
            css: 'grid-class-name',
            grid_container: 'grid_will_display_here',
            toolbar_container: 'grid_toolbar_will_display_here',
            dto: {VUE: 'JSON'},
            columns: [
                {label: 'Full Name', value: function(e) {
                    return e.lname.toUpperCase() + ' ' + e.name;
                }},
                {label: 'Gender', value: 'gender', css: 'tcenter', default_value: 'unknown'}
            ],
            actions: [
                {
                    label: 'Add',
                    condition: function() {return this.rights.can_create},
                    callback: function()  {alert('Add action has been called')}
                }
            ],
            grabfocus: true,
            onShow: function() {

            },
            onEmpty: function() {
                $('grid_will_display_here').update('empty list was retrieved');
            },
            onPing: function(target) {
                alert('record:\n'+$H(target).inspect() + '\nin grid has been pinged!')}
            },
            onCancel: function() {alert('ESC pressed')}
        });

## DEPENDENCIES

This class depends on the following GvaScript classes:

- GvaScript.ChoiceList
- GvaScript.Paginator
- GvaScript.CustomButtons

## DESTRUCTOR

      my_grid.destroy();

This method will unregister the Grid in the GvaScript.Grids namespace and will iteratively call the destructor on all the grid's depedencies this removing all handlers attached. Call this method when the grid is removed from the DOM.

## DESCRIPTION

Displays a dataset in a grid format. Dataset is bound to a JSON datasource retrieved via an AJAX request.

JSON object has a predefined format that the Grid class understands and renders.

A Grid is made up of two components:

- Grid Result

  The grid (table) that would be the container to display the result dataset. Result is displayed with the help of `GvaScript.ChoiceList`.

- Grid Toolbar

  The grid's toolbar that would be the container to display grid's actions and pagination links. Toolbar is displayed with the help of `GvaScript.CustomButtons` and `GvaScript.Paginator`

### GvaScript.Grids

interface that provides one useful method:

#### GvaScript.Grids.get(id)

finds and returns the Grid instance where id is the unique id of the grid.

## BEHAVIOUR

Grid's display is based on a `GvaScript.ChoiceList` object and thus has the behaviour of that of a choice list.

### Grid Navigation Behaviour

- `DOWN` / `UP`

  navigate by recordCustomButtons

- `HOME` / `END`

  start/end of current page CustomButtons =item `RETURN`

  fires onPing event handler

- `ESC`

  fires onCancel event handler

- `PAGEUP / LEFT` and `PAGEDOWN / RIGHT`

  navigate by page

- `[Ctrl-HOME]` and `[Ctrl-END]`

  navigate to first and last page correspondingly.

## JSON Datasource

As mentioned before, the Grid expects the JSON datasource object to be of a predefined format.

      json = {
        'liste'  : [
            {'fname': 'John',    'lname': 'Stiles', 'gender': 'm'},
            {'fname': 'Mary',    'lname': 'Major',  'gender': 'f'},
            {'fname': 'Richard', 'lname': 'Miles',  'gender': 'm'}
        ],
        'total'  : 15,
        'rights' : {
            can_create : 0,
            can_update : 1,
            can_delete : 0
        }
      };

- liste (Array)

  array of records.

  mandatory.

- total (numeric)

  total number of records that are being paginated.

  mandatory.

- rights (JSON Object)

  object containing the access rights to the records in the list. Rights values should be boolean expressions. this object will be stored and referenced later via `grid.rights` for grid actions conditions.

## CONSTRUCTOR

      var grid = new GvaScript.Grid(id, url, options);

### id

A unique id to identify a Grid. Might be later used in `GvaScript.Grids.get(id)` to retrieve the grid instance.

### url

Url for AJAX request to retrieve current page dataset.

### options

- css (String)

  A string value of space seperated list of class names to be applied to the table element.

  optional - defaulted to ''

- dto (JSON Object)

  Data transfer Object to the AJAX request. `Ex: {param1: 'value1', param2: 'value2'}`

  optional - defaulted to `{VUE: 'JSON'}`

- method (String)

  HTTP method to open in the AJAX request.

  optional - defaulted to `'post'`

- columns (Array)

  Array of objects that defines the grid columns.

  Ex column object:

          {
              label: 'Gender',
              value: 'gender',
              css: 'tcenter',
              default_value: 'unknown'
          }

  - label (string)

    column label. can be an empty string

    mandatory.

  - value (string|Function)

    string representing the key of the json element that the column is bound to.

    Function that takes the records as an argument and returns string value of the column. Ex: `value: function(e) {return e.fname + ' ' + e.lname}`

    mandatory.

  - default_value (string)

    string value representing the column's default value if no value was found in the JSON datasource.

    optional.

  - css (string|Array)

    a single css class or and array of css classes to be given to the column header/cells.

    optional.

- actions (Array)

  Array that defines the grids list of actions (to be rendered in the grid's tool bar).

  Action object here is identical to GvaScript.CustomButtons.Button.options

- grabfocus (boolean)

  boolean indicating whether the grid container is to grab focus right after the grid has been initialized.

  optional - defaulted to `true`

- pagesize (numeric|'auto')

  a numeric specifying number of records to show on a page. To keep this number variable and dependant on grid's container available space, set it to 'auto'.

  optional - defaulted to `'auto'`

- gridheight (numeric|'auto')

  height to set to the grid. To keep this number variable and dependant on the grid's container available space, set it to 'auto'.

  optional - defaulted to `'auto'`

- recordheight (numeric)

  height to set to the grid record.

  optional - defaulted to `21`

- requestTimeout (numeric)

  time in seconds to wait before aborting the AJAX request.

  optional - defaulted to 15

- errorMsg (string)

  message to display in the grid container area when the request times out.

  optional - defaulted to "Problème de connexion. Réessayer et si le problème persiste, contacter un administrateur.".

## PROPERTIES

Here's a list of useful properties of the Grid Object.

### grid_container

      grid.grid_container

`HTMLElement` container of the grid list

### toolbar_container

      grid.toolbar_container

`HTMLElement` container of the toolbar (pagination links + action buttons)

### paginatorbar_container

      grid.paginatorbar_container

`HTMLElement` container of the pagination links

### actionsbar_container

     grid.actionsbar_container

`HTMLElement` container of the action buttons

## METHODS

### clearResult

      grid.clearResult(msg)

This method clears the grid result container and displays `msg` instead.

### clearToolbar

      grid.clearToolbar()

This methods clears the grid toolbar container.

### clearActionButtons

      grid.clearActionButtons()

This method clears the action buttons container and thus removes the buttons

### clear

      grid.clear(msg)

This method is equivalent to `grid.clearResult(msg)` and `grid.clearToolbar()`

### addActionButtons

      grid.addActionButtons()

This method renders the action buttons based on the grids actions. NOTE that the actions conditions will be re-evaluated.

## EVENTS

### onShow

This event is triggered of the table is rendered and displayed. Useful for attaching custom events on table records/cells.

### onHighlight

This event is triggered when a choice in the list is highlighted. The event handler may use `event.index` to know the index of the highlighted choice.

### onPing

This event is triggered when a choice in the list is "ping-ed", i.e. either by dblclicking, clicking on selected row or by pressing the `RETURN` key. The event handler will recieve 1 arguement `target` which is the record object that has been "Pinged".

Ex: `{'fname': 'Mary', 'lname': 'Major', 'gender': 'f'}`

### onCancel

This event is triggered when the user presses the `ESCAPE` key.

### onEmpty

This event is triggered when the list is empty.

## EXAMPLE

### JAVASCRIPT

      var my_url  = "/app/path/to/data/list";
      var my_grid = new GvaScript.Grid("ex_grid", my_url, {
        grid_container: 'ex_grid_list',
        toolbar_container: 'ex_grid_toolbar',
        dto: {VUE: 'JSON'},
        pagesize: 3,
        columns: [
            {label: 'Full Name', value: function(e) {
                return e.fname + ' ' + e.lname;
            }},
            {label: 'Gender', value: 'gender', css: 'tcenter', default_value: 'unknown'}
        ],
        actions: [
            {
                label: 'Add',
                condition: function() {return this.rights.can_create},
                callback: function()  {alert('Add action has been called')}
            }
        ]
      });

      // my_url response : Content-type "application/json"
      {
        'liste'  : [
            {'fname': 'John',    'lname': 'Stiles', 'gender': 'm'},
            {'fname': 'Mary',    'lname': 'Major',  'gender': 'f'},
            {'fname': 'Richard', 'lname': 'Miles',  'gender': 'm'}
        ],
        'total'  : 15,
        'rights' : {
            can_create : 0,
            can_update : 1,
            can_delete : 0
        }
      }

### HTML

      <div id="ex_container">

       <div tabindex="0" id="ex_grid_list">
         <table class="dmweb-grid">
           <thead>
             <tr>
               <th class="grid-marker"> </th>
               <th class="grid-header">Full Name</th>
               <th class="grid-header">Gender</th>
            </tr>
           </thead>
           <tbody>
            <tr id="ex_grid_list.CL_choice.0" class="CL_choiceItem liste_highlight">
               <td class="grid-marker"> </td>
               <td valign="top" class="grid-cell index_0">John Stiles</td>
               <td valign="top" class="grid-cell index_0 tcenter">m</td>
            </tr>
            <tr id="ex_grid_list.CL_choice.1" class="CL_choiceItem">
               <td class="grid-marker"> </td>
               <td valign="top" class="grid-cell index_1">Mary Major</td>
               <td valign="top" class="grid-cell index_1 tcenter">f</td>
            </tr>
             <tr id="ex_grid_list.CL_choice.3" class="CL_choiceItem">
               <td class="grid-marker"> </td>
               <td valign="top" class="grid-cell index_0">Richard Miles</td>
               <td valign="top" class="grid-cell index_0 tcenter">m</td>
            </tr>
          </tbody>
        </table>
       </div>

       <div id="ex_grid_toolbar" class="dmweb-grid-toolbar">
        <div class="dmweb-paginatorbar">
          <div title="Dernière page" class="last"></div>
          <div title="Page suivante" class="forward"></div>
          <div class="text">1 à 3 de 15</div>
          <div title="Page précédente" class="back inactive"></div>
          <div title="Première page" class="first inactive"></div>
        </div>
        <div class="dmweb-grid-actionsbar">
          <span id="grid_id_btn_0" class="dmweb-btn-container">
            <span class="left"/>
            <span class="center">
              <button class="btn" style="width: auto;" type="button">Add</button>
            </span>
            <span class="right"/>
          </span>
        </div>
       </div>

      </div>

### CSS

      /* class given to grid list container when an AJAX request is being affected */
      .dmweb-loading {
        background:url(ajax_loading.gif) no-repeat center center;
        position:absolute;
        width:30px;height:30px;
        top:50%;left:50%;
      }

      /* grid toolbar */
      .dmweb-grid-toolbar {
        background:#C5CCE8 url(glass-bg-n.gif) repeat-x scroll left top;
        border:1px solid #A3BAD9;
        height:28px;
      }
      .dmweb-grid-actionsbar {float:left;}
      .dmweb-paginatorbar {float:right;width:250px;}
      .dmweb-paginatorbar div {width:16px;height:16px;cursor:pointer;float:right;}
      .dmweb-paginatorbar div.first {background:url(page-first.gif) no-repeat top center;}
      .dmweb-paginatorbar div.last {background:url(page-last.gif) no-repeat top center;}
      .dmweb-paginatorbar div.back {background:url(page-prev.gif) no-repeat top center;}
      .dmweb-paginatorbar div.forward {background:url(page-next.gif) no-repeat top center;}
      .dmweb-paginatorbar div.inactive {cursor:default;opacity:0.25;filter:alpha(opacity=25);}
      .dmweb-paginatorbar div.text {text-align:center;width:140px;color:#4b34c5;font-size:10pt;}
      .dmweb-paginatorbar span.dmweb-btn-container {display:block;margin-right:4px;}

      /* grid table */
      .dmweb-grid {width:100%;}
      .dmweb-grid th.grid-header {
        text-align:center;
        padding:2px;
        font-size:75%;
        color: #183E6C;
        background-color: #D0D6ED;
        border:1px solid #6F82A5;
      }
      .dmweb-grid td {font-size:75%;color:#183E6C;}
      .dmweb-grid .grid-marker {width:15px;background-color: #D0D6ED;border:1px solid #6F82A5;}
      .dmweb-grid tr.liste_highlight td.grid-marker {
        background: #D0D6ED url(selector.gif) no-repeat center center;
      }
      .dmweb-grid tr.liste_highlight td.grid-cell {background-color: #6F82A5 !important;color:#f5f5f5 !important;}
      .dmweb-grid td.grid-cell {padding:2px !important;border:1px solid #e8e8e8;}
      .dmweb-grid td.grid-cell.index_1 {background-color:#EFEFEF;}
      .dmweb-grid td.grid-cell.center {text-align:center;float:none;}
      .dmweb-grid td.grid-cell.right {text-align:right;float:none;}
      .dmweb-grid td.grid-cell.red {color:red;}