# XML Support For Tcl

### TclXML

### Steve Ball

Zveno Pty Ltd

www.zveno.com

$Id: README.html,v 1.1 2003/03/09 20:16:27 balls Exp $

Revision History
Revision 2.6 |

This package provides XML parsers for Tcl scripts. There is a generic front-end interface with plugin parser implementations. A number of parser implementations or wrappers are provided:

- James Clark's expat library

- A generic Tcl implementation, (if you can't be bothered compiling an extension)

The packages define commands in the `::xml` Tcl namespace:

xml::parserclass [info] [names]
xml::parser

Other packages are also provided to provide support for related standards. In particular, work has commenced on the 'xpath' package for parsing XPath location paths.

See the website for more information on XML support for Tcl.

Contact Steve Ball for information about this release.

## Installation

TclXML v2.6 features a pure-Tcl installer.

Future work on the installer will include an 'uninstall' capability, as well as the capability to build the binary libraries in the package from the source.

### Dependencies

Tcllib

  http://dev.scriptics.com/software/tcllib/

  In order for the Tcl-only parser to resolve external entities, the tcllib package must be installed.

  Be sure to get a version which includes the `uri` package. Version 1.2 or better is recommended.

  - GZip'd tarball

  - ZIP file

  The latest CVS snapshot may be found at the SourceForge project page.

Expat

  Expat is only required for the compiled version of the package.

  TclXML/expat requires expat v0.2, with modifications by Ajuba Solutions. This is now supplied in the `expat` subdirectory of this distribution and will maintained until Tclxml has been resynchronised with the Expat SourceForge project (volunteer needed!).

### Pure-Tcl Installation

#### no compilation required

The `install.tcl` script will install the pure-Tcl parser. Run it using wish, eg.

    wish install.tcl

### Note

If Tcl/Tk has been configured correctly on your system, you should be able to simply double-click the script

If the pure-Tcl parser is good enough for you, then read no further.

### Compiled Installation

#### Unix/Linux

You must have Tcl/Tk version 8.2 or better installed on your system. Tcl/Tk 8.3 or better is recommended.

1. Make sure you have Tcllib 1.2 (or better) installed. Tcllib is still required, even for the compiled parser.

2. Unpack the TclXML distribution and cd into the `tclxml-2.6` directory.

3. Run the `configure` script, with the [--prefix], [--exec_prefix] and [--enable-threads] switches (the latter only if Tcl has been built with threads enabled). For example, on my system I have Tcl 8.4 installed in `/usr/local/tcl8.4` so I would use the command:

       ./configure --prefix=/usr/local/tcl8.4 --exec_prefix=/usr/local/tcl8.4 --enable-threads

4.     make

5.     make install

   You may need to do this as root. This installs the pure-Tcl parser class, as well as support files required for the next step.

6.     cd expat

   Now TclXML/expat is about to be built.

7. Use exactly the same configure command from step (2) above.

8.     make

9.     make install

   You may need to do this as root. This installs the expat parser class.

#### WINDOWS (MS VC++)

### Note

[Warning: these instructions may not be up-to-date.]

### Note

[Advice: ActiveTcl includes binaries for TclXML.]

You must have Tcl/Tk version 8.2 or better installed on your system. Tcl/Tk 8.3 or better is recommended.

1. Run MS Visual C++ and load the tclxml workspace in the win subdirectory. There are project files for tclxml, tclexpat & expat. The active project will be the Release version of tclexpat.

2. To build tclxml without tclexpat, select the tclxml project and just build that.

3. Installation

   Since you must have tcl/tk installed already (!) you might like to use the new installer that we have been working on.

   You can install one of multiple builds (Release/Debug etc) by invoking the install.tcl script and specifying the directory path to the build, or by invoking the installer from the build directory directly:

       cd win
       wish ../install.tcl -builddir Release

   or

       cd win/Release
       wish ../../install.tcl

   Various screens will appear allowing you to select where the package is installed, what optional components can be installed and showing a log of the installation process.

   If that doesn't do the deed you need to do some hard yards:

   - Copy the DLL's in the target build subdirectory (win/Release or win/Debug) to a directory which is in your execution PATH (the same directory as your TCL/TK binaries is an obvious one).

   - Copy the top level library subdirectory and its contents into a directory which will be part of the autoexec_path in any TCL/TK apps that will need to load the tclxml modules (the lib subdirectory of your TCL/TK installation is one) . Rename the directory to tclxml2.6

   - Rename the file pkgIndex.tcl.in in this directory to pkgIndex.tcl, and edit the file, replacing any macros (strings with leading and trailing '@''s) with approriate directory/lib/paths.

     @RELPATH@ = relative path between the library directory
     & the dll's directory
     @TCLXML_LIB_FILE@ = tclxml.dll
     @expat_TCL_LIB_FILE@ = tclexpat.dll

#### Macintosh OS X

There are two ways to build TclXML under Mac OS X:

1. The usual Unix way, see above.

2. As a Framework using ProjectBuilder.

The `macosx` directory contains the Project Builder files for building under OS X. TclXML has been tested on OS X 10.2.3 (or is that X.2.3?).

Start-up the project, select the 'expat' target and build. This builds everything. The result is a Mac OS X Framework. Copy `tclxml.framework` and `expat.framework` to any of the usual places for frameworks (`~/Library/Frameworks`, `/Library/Frameworks`, etc).

#### Macintosh OS 9 (or earlier)

The installer script doesn't work properly on Macintosh yet, and the binary parsers have not been ported yet (sorry).

Since the distribution has an all-Tcl parser, you can get a working parser fairly easily.

Copy the `library` folder to the Tcl library folder in the Extensions folder of the System folder.

Rename the `library` folder to `tclxml2.6`. This isn't strictly necessary, but it helps keep things organised.

You're on your own as far as the demos, programs and documentation go.

## Usage

See the website for links to tutorials and the reference manual.

In the meantime, here's a quick tutorial:

    package require xml

    set parser [xml::parser]
    $parser configure -elementstartcommand EStart \
        -characterdatacommand PCData

    proc EStart {tag attlist args} {
        array set attr $attlist
        puts "Element \"$tag\" started with [array size attr] attributes"
    }

    proc PCData text {
        incr ::count [string length $text]
    }

    set count 0
    $parser parse [read stdin]

    puts "The document contained $count characters"
    exit 0

## XPath

In addition to XML parsing packages, TclXML also provides a package for parsing XPath location paths. The XPath package only parsing the path's syntax, it does interpret the path. See TclDOM for a package that will interpret XPath location paths.

NB. This package is in its infancy, and does not support the full range of XPath features. Only a very limited subset of location paths are supported, of the form "/simple/example[2]". Paths within predicates will definitely fail.

To use the XPath package:

    package require xpath

To parse a location path:

    xpath::split {/simple/example}

This returns a Tcl list, each element of which is a three element sublist: {axis node-test {?predicate ...?}}.