Check for plugin dependencies

1 Requirements

A plugin may require another plugin to be installed and active in order to work. Currently this check has to be done by the developer manually, e.g. check in ilPlugin::beforeActivate() method if the other plugin is installed/active. At the moment, it is not yet possible to check preconditions before installing/updating the plugin. A method ilPlugin::beforeUpdate() has been added to the trunk which would support this scenario.
 
However, we think that checking dependencies should be done by ILIAS. If a plugin has dependencies, the developer can specify them in a method. See the sample code below:

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public static function getDependencies() {
  return array(
    'plugin_id1' => 'Plugin title/description',
    'plugin_id2' => 'Plugin title/description,
  );
}

If the plugin returns a non-empty array, ILIAS could check if all the plugins in the array are installed and active. If one or several dependencies are not fullfilled, then ILIAS would abort the update/activate process and display a useful error message to the user.

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2 Status

• Scheduled for: Not scheduled yet (will be set by Jour Fixe)
• Funding: Required / Partly funded by / Funded by ... (please indicate if you have funding for feature)
• Maintainer: (will be set by Jour Fixe)
• Implementation of the feature is done by (company, developer)
• Contract settled: (fill in "Yes" if a contract is already settled, otherwise "No" )
• Tested by / status: (name, e-mail), (status information set after implementation)

3 Additional Information

Contact the following persons if you want to know more about this feature, its implementation or funding:

• Information about concept: Stefan Wanzenried, sw@studer-raimann.ch
• Information about funding: (name, e-mail)
• Information about implementation: (name, e-mail)

4 Discussion

5 Implementation

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