Since CONTENIDO 4.9 plugins are installed via the Plugin manager.

Beside plugins from the community (so called third party plugins) CONTENIDO itself is released with various default plugins, which can be activated without downloading them.

Structure of a plugin

Plugins must follow a given structure so they can be installed correctly. Once at all, all files of a plugin package are packed to an ZIP archive, which later is unpacked from the installation routine of the plugin manager.

The content of this ZIP file must fit to the following guidelines.

ZIP archive filename

The name of the ZIP archive file must only contain the plugin name, for example: linkchecker.zip

plugin.xml

Each plugin must have a XML file which contains metadata for the plugin itself and for the installation in the system. Among other things this file is responsible for the folder name in the plugins directory of CONTENIDO. Most important it contains all relevant entries for some special database tables, so the plugin is accessible in the backend (creating menu entries and so on). These tables are: actions, area, files, frame_files and nav_sub.

The XML is divided into multiple parts - each separated to a XML tag. XML files must be valid against the plugin file schema located at xml/plugin_info.xsd located in the plugin managers plugin directory.

Universal Unique Identifier (UUID)

Each plugin must have an UUID to identify it globally. These IDs base on the values for the plugin_name and copyright fields in this file. UUIDs only can be generated on the CONTENIDO website. 

Tag general - meta information (required)

This tag contains meta information about the plugin which also are displayed in frontend. The tag has the attribute "active" which should have the value "1".

<general active="1">
        <plugin_name>Linkchecker</plugin_name>
        <plugin_foldername>linkchecker</plugin_foldername>
        <uuid>428CB6BC-2DE3-284D-34C9-C30C010F6B20</uuid>
        <description>Checks intern and extern links to valid</description>
        <author>Frederic Schneider (4fb)</author>
        <copyright>four for business AG</copyright>
        <mail>frederic.schneider@4fb.de</mail>
        <website>http://www.4fb.de</website>
        <version>2.0.1</version>
</general>

Tag requirements - requirements for new plugins

    <requirements php="5.2.3">
        <contenido minversion="4.9.0" />
        <extension name="mysql" />
        <class name="cRegister" />
        <function name="i18n" />
    </requirements>

Tag contenido - database specific information

This tag contains database specific information for adding entries to special database tables (mentioned above) to be able to display the plugin in the backend navigation.

Each tag expects attributes which have the same value as their fields in the corresponding database table.

The order of the XML tags must be the same as listed below.

<areas>
	<area parent="linkchecker" menuless="1">lc_whitelist</area>
</areas>

<actions>
	<action area="linkchecker">linkchecker</action>
</actions>

<frames>
	<frame area="linkchecker" filetype="main" name="linkchecker/includes/include.linkchecker.php" frameId="4" />
</frames>

<nav_main>
	<nav>locationname</nav>
</nav_main>

<nav_sub>
	<nav area="linkchecker" level="0" navm="1">linkchecker/xml/lang_de_DE.xml;navigation/content/linkchecker/main</nav>
</nav_sub>

Tag content_types - registration of own content types

This tag contains information to register own content types.

<content_types>
	<type>CMS_NAME</type>
</content_types>

Tag plugin_dependencies - dependencies to other plugins

This tag is reserved for further implementations of plugin dependencies. The structure of tags is not final and may change.

plugin_install.sql, plugin_uninstall.sql and plugin_update.sql

These files contain additional statements executed on the installation, uninstall or update of the plugin. 

Both files expects one statement per line. Multi line statements are currently not supported and will lead to errors.

Because plugin database tables must have a special prefix, a special keyword "!PREFIX!" is available to replace it accordingly. Statements, which does not contain this placeholder are not executed.

Furthermore, it is only possible to execute the following database operations.

The prefix placeholder contains the common database table prefix (per default: "con_") following by the chars "pi" for plugin.

INSERT INTO !PREFIX!_news_log ...
gets
INSERT INTO con_pi_news_log ...