# Plugin for TWiki Enterprise Collaboration Platform, http://TWiki.org/
#
# Copyright (C) 2000-2003 Andrea Sterbini, a.sterbini@flashnet.it
# Copyright (C) 2001-2006 Peter Thoeny, peter@thoeny.org
# and TWiki Contributors. All Rights Reserved. TWiki Contributors
# are listed in the AUTHORS file in the root of this distribution.
# NOTE: Please extend that file, not this notice.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version. For
# more details read LICENSE in the root of this distribution.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# For licensing info read LICENSE file in the TWiki root.

=pod

---+ package XmlXslPlugin

=cut

# change the package name and $pluginName!!!
package TWiki::Plugins::XmlXslPlugin;

# Always use strict to enforce variable scoping
use strict;

require TWiki::Func;    # The plugins API
require TWiki::Plugins; # For the API version

# $VERSION is referred to by TWiki, and is the only global variable that
# *must* exist in this package.
use vars qw( $VERSION $RELEASE $SHORTDESCRIPTION $debug $pluginName $NO_PREFS_IN_TOPIC );

# This should always be $Rev: 15942 (22 Jan 2008) $ so that TWiki can determine the checked-in
# status of the plugin. It is used by the build automation tools, so
# you should leave it alone.
$VERSION = '$Rev: 15942 (22 Jan 2008) $';

# This is a free-form string you can use to "name" your own plugin version.
# It is *not* used by the build automation tools, but is reported as part
# of the version number in PLUGINDESCRIPTIONS.
$RELEASE = 'TWiki-4.2';

# Short description of this plugin
# One line description, is shown in the %TWIKIWEB%.TextFormattingRules topic:
$SHORTDESCRIPTION = 'Empty Plugin used as a template for new Plugins';

# You must set $NO_PREFS_IN_TOPIC to 0 if you want your plugin to use preferences
# stored in the plugin topic. This default is required for compatibility with
# older plugins, but imposes a significant performance penalty, and
# is not recommended. Instead, use $TWiki::cfg entries set in LocalSite.cfg, or
# if you want the users to be able to change settings, then use standard TWiki
# preferences that can be defined in your Main.TWikiPreferences and overridden
# at the web and topic level.
$NO_PREFS_IN_TOPIC = 1;

# Name of this Plugin, only used in this module
$pluginName = 'XmlXslPlugin';

=pod

---++ initPlugin($topic, $web, $user, $installWeb) -> $boolean
   * =$topic= - the name of the topic in the current CGI query
   * =$web= - the name of the web in the current CGI query
   * =$user= - the login name of the user
   * =$installWeb= - the name of the web the plugin is installed in

REQUIRED

Called to initialise the plugin. If everything is OK, should return
a non-zero value. On non-fatal failure, should write a message
using TWiki::Func::writeWarning and return 0. In this case
%FAILEDPLUGINS% will indicate which plugins failed.

In the case of a catastrophic failure that will prevent the whole
installation from working safely, this handler may use 'die', which
will be trapped and reported in the browser.

You may also call =TWiki::Func::registerTagHandler= here to register
a function to handle variables that have standard TWiki syntax - for example,
=%MYTAG{"my param" myarg="My Arg"}%. You can also override internal
TWiki variable handling functions this way, though this practice is unsupported
and highly dangerous!

__Note:__ Please align variables names with the Plugin name, e.g. if 
your Plugin is called FooBarPlugin, name variables FOOBAR and/or 
FOOBARSOMETHING. This avoids namespace issues.


=cut

sub initPlugin {
    my( $topic, $web, $user, $installWeb ) = @_;

    # check for Plugins.pm versions
    if( $TWiki::Plugins::VERSION < 1.026 ) {
        TWiki::Func::writeWarning( "Version mismatch between $pluginName and Plugins.pm" );
        return 0;
    }

    # Example code of how to get a preference value, register a variable handler
    # and register a RESTHandler. (remove code you do not need)

    # Set plugin preferences in LocalSite.cfg, like this:
    # $TWiki::cfg{Plugins}{XmlXslPlugin}{ExampleSetting} = 1;
    # Always provide a default in case the setting is not defined in
    # LocalSite.cfg. See TWiki.TWikiPlugins for help in adding your plugin
    # configuration to the =configure= interface.
    # my $setting = $TWiki::cfg{Plugins}{XmlXslPlugin}{ExampleSetting} || 0;
    $debug = $TWiki::cfg{Plugins}{XmlXslPlugin}{Debug} || 0;

    # register the _EXAMPLETAG function to handle %EXAMPLETAG{...}%
    # This will be called whenever %EXAMPLETAG% or %EXAMPLETAG{...}% is
    # seen in the topic text.
    TWiki::Func::registerTagHandler( 'EXAMPLETAG', \&_EXAMPLETAG );

    # Allow a sub to be called from the REST interface 
    # using the provided alias
    TWiki::Func::registerRESTHandler('example', \&restExample);

    # Plugin correctly initialized
    return 1;
}

# The function used to handle the %EXAMPLETAG{...}% variable
# You would have one of these for each variable you want to process.
sub _EXAMPLETAG {
    my($session, $params, $theTopic, $theWeb) = @_;
    # $session  - a reference to the TWiki session object (if you don't know
    #             what this is, just ignore it)
    # $params=  - a reference to a TWiki::Attrs object containing parameters.
    #             This can be used as a simple hash that maps parameter names
    #             to values, with _DEFAULT being the name for the default
    #             parameter.
    # $theTopic - name of the topic in the query
    # $theWeb   - name of the web in the query
    # Return: the result of processing the variable

    # For example, %EXAMPLETAG{'hamburger' sideorder="onions"}%
    # $params->{_DEFAULT} will be 'hamburger'
    # $params->{sideorder} will be 'onions'
}

=pod

---++ commonTagsHandler($text, $topic, $web, $included, $meta )
   * =$text= - text to be processed
   * =$topic= - the name of the topic in the current CGI query
   * =$web= - the name of the web in the current CGI query
   * =$included= - Boolean flag indicating whether the handler is invoked on an included topic
   * =$meta= - meta-data object for the topic MAY BE =undef=
This handler is called by the code that expands %<nop>TAGS% syntax in
the topic body and in form fields. It may be called many times while
a topic is being rendered.

For variables with trivial syntax it is far more efficient to use
=TWiki::Func::registerTagHandler= (see =initPlugin=).

Plugins that have to parse the entire topic content should implement
this function. Internal TWiki
variables (and any variables declared using =TWiki::Func::registerTagHandler=)
are expanded _before_, and then again _after_, this function is called
to ensure all %<nop>TAGS% are expanded.

__NOTE:__ when this handler is called, &lt;verbatim> blocks have been
removed from the text (though all other blocks such as &lt;pre> and
&lt;noautolink> are still present).

__NOTE:__ meta-data is _not_ embedded in the text passed to this
handler. Use the =$meta= object.

*Since:* $TWiki::Plugins::VERSION 1.000

=cut

sub commonTagsHandler {
    # do not uncomment, use $_[0], $_[1]... instead
    ### my ( $text, $topic, $web, $meta ) = @_;

    TWiki::Func::writeDebug( "- ${pluginName}::commonTagsHandler( $_[2].$_[1] )" ) if $debug;

    # do custom extension rule, like for example:
    # $_[0] =~ s/%XYZ%/&handleXyz()/ge;
    # $_[0] =~ s/%XYZ{(.*?)}%/&handleXyz($1)/ge;
    
    my $ctr = 0;

    $_[0] =~ s/%XMLXSLTRANSFORM{(.*)}%/&applyXmlToXsl($1, $ctr++)/ge;

}

=pod

---++ postRenderingHandler( $text )
   * =$text= - the text that has just been rendered. May be modified in place.

__NOTE__: This handler is called once for each rendered block of text i.e. 
it may be called several times during the rendering of a topic.

__NOTE:__ meta-data is _not_ embedded in the text passed to this
handler.

Since TWiki::Plugins::VERSION = '1.026'

=cut

sub DISABLE_postRenderingHandler {
    # do not uncomment, use $_[0], $_[1]... instead
    #my $text = shift;

    # $_[0] =~ s/%XMLXSLTRANSFORM{(.*)}%/&applyXmlToXsl($1,$2)/ge;
}

sub applyXmlToXsl
{
    my $theArgs = $_[0];
	my $ctr = $_[1];
    my $scriptGeneric = &getScriptGenericText($ctr);
    
    my $xmlsource = &TWiki::Func::extractNameValuePair( $theArgs, "xml" );
    my $xslsource = &TWiki::Func::extractNameValuePair( $theArgs, "xsl" );
	my $csssource = &TWiki::Func::extractNameValuePair( $theArgs, "css" ) || "";
	my $id = &TWiki::Func::extractNameValuePair( $theArgs, "id" ) || "id$ctr"; # must always start with a letter

    TWiki::Func::writeDebug( "apply: xmlsource='$xmlsource'\nxslsource='$xslsource'\n" ) if $debug;

   my $script = <<'END';
<script>
xml=loadXMLDoc("%XML%");
xsl=loadXMLDoc("%XSL%");
// code for IE
if (window.ActiveXObject)
  {
  ex=xml.transformNode(xsl);
  document.getElementById("showResult%ID%").innerHTML=ex;
  }
// code for Mozilla, Firefox, Opera, etc.
else if (document.implementation && document.implementation.createDocument)
  {
  xsltProcessor=new XSLTProcessor();
  xsltProcessor.importStylesheet(xsl);
  resultDocument = xsltProcessor.transformToFragment(xml,document);
  document.getElementById("showResult%ID%").appendChild(resultDocument);
  }
</script>
END

    $script =~ s/%ID%/$id/g;
    $script =~ s/%XML%/$xmlsource/g;
    $script =~ s/%XSL%/$xslsource/g;
    return  $scriptGeneric . "<DIV id=\"showResult$id\"></DIV>" . $script;
}

sub getScriptGenericText
{
	return "" if $_[0] > 0;
	my $script = <<'END';
<script>
function loadXMLDoc(fname)
{
var xmlDoc;
// code for IE
if (window.ActiveXObject)
  {
  xmlDoc=new ActiveXObject("Microsoft.XMLDOM");
  }
// code for Mozilla, Firefox, Opera, etc.
else if (document.implementation && document.implementation.createDocument)
  {
  xmlDoc=document.implementation.createDocument("","",null);
  }
else
  {
  alert('Your browser cannot handle this script');
  }
xmlDoc.async=false;
xmlDoc.load(fname);
return(xmlDoc);
}
</script>
END

return $script;
	
}

1;