View source for Creating a content plugin

==INI file(s)==
For internationalization it is good to use the INI files. You can add to the language file everything which outputs text to the user, in this order: 
*XML description tag 
*XML label and description attributes from parameters 
*JText::_( 'string' ) used by the plugin

You should create two files: One for the backend and one for the front end. The naming should match the path of the extension. For example, if we were creating a content plugin named 'example' and it is installed at plugins/content/example, then our files should be named:
*en-US.plg_content_example.ini (Frontend)
*en-US.plg_content_example.sys.ini (Backend)

 
Start your INI file with something like this: 
<source lang="INI"># $Id: en-GB.plg_content_nameofplugin.ini
# Joomla! Project
# Copyright (C) 2005 - 2007 Open Source Matters. All rights reserved.
# License http://www.gnu.org/licenses/gpl-2.0.html GNU/GPL, see LICENSE.php
# Note : All ini files need to be saved as UTF-8 - No BOM</source>
Of course, you could also add other information, like the author. 

Joomla 1.6+ uses the ; at the start of the line, rather than the #.

Backend Example: 
<source lang="XML">
<param name="mode" type="list" default="1" label="PLG_CONTENT_EXAMPLE_MODE" description="PLG_CONTENT_EXAMPLE_EMAILS_DISPLAYED">
   <option value="0">PLG_CONTENT_EXAMPLE_NONLINKABLE_TEXT</option>
   <option value="1">PLG_CONTENT_EXAMPLE_LINKABLE_TEXT</option>
</param></source>

The localized strings are translated in the ini file:
<source lang="INI">
PLG_CONTENT_EXAMPLE_MODE=Mode
PLG_CONTENT_EXAMPLE_EMAILS_DISPLAYED=Select how the e-mails will be displayed
PLG_CONTENT_EXAMPLE_NONLINKABLE_TEXT=Nonlinkable text
PLG_CONTENT_EXAMPLE_LINKABLE_TEXT=As linkable mailto address
</source>

Best practice dictates that LOCALIZED_TAGS are all upper case, no spaces, and begin with the same name as the extension - to avoid interfering with other strings.

The localized tags can then be translated into multiple languages.When you want to make your Content Plugin available in more languages, first add them to the <languages> tag in the XML file. Then create the same INI file, and change the part after the =, for example the dutch version would be: 
<source lang="INI">
PLG_CONTENT_EXAMPLE_MODE=Modus
PLG_CONTENT_EXAMPLE_EMAILS_DISPLAYED=Selecteer hoe de e-mails worden weergegeven
PLG_CONTENT_EXAMPLE_NONLINKABLE_TEXT=Niet-linkbare tekst
PLG_CONTENT_EXAMPLE_LINKABLE_TEXT=Als een linkbaar mailto adres
</source>

Frontend Example:
On Joomla 1.6+ you must create a separate file for the front end - as described above. For example:

<source lang="INI">
PLG_CONTENT_EXAMPLE_LINKNAME="The Name of the Link Goes Here!"
</source>

In the plugin's php file, you must load the language file:
<source lang="PHP">
// Load user_profile plugin language
$lang = JFactory::getLanguage();
$lang->load('plg_content_simpleattachment', JPATH_ADMINISTRATOR);
echo JText::_('PLG_CONTENT_EXAMPLE_LINKNAME');
</source>

You could also use another component or plugin's language file.  This is useful for maintaining consistent strings between a component, module, and plugin, that are part of the same package.

To load another component or plugin's language files specify it's name in the load statement and specify whether to use the site or administrator language.  For example:

<source lang="PHP">
$lang->load('com_someothercomponent',JPATH_ADMINISTRATOR);
</source>