Frequently Asked Questions about Redmine plugins

This page aims at documenting how to achieve simple things in Redmine plugins.

Determine if a module is enabled

If your project is in the @project variable:

if @project.module_enabled?("<module_name>")

First modules are a project level concept. So be sure to make this check in an action that operates at project level. Redmine core generally uses a before_filter called find_project to find the current project in standard actions, which populates the @project variable.

Available modules as of Redmine 2.3.x are: boards, calendar, documents, files, gantt, issue_tracking, news, repository, time_tracking, wiki. Each plugin can add its own module (see Plugin_Tutorial which adds a "polls" module).

Changing the layout of a page

Changing the layout of a page is done by overriding its View. Redmine stores its views in app/views/. To change a page's view using a plugin, first copy the view from app/views/ to plugins/your_plugin/app/views/ and then modify the file.

If multiple plugins override the same view, the last plugin loaded will be the one whose view is shown. If you are having trouble finding out which view you need to override, check config/routes.rb and look for a pattern that matches the URL for the page you are trying to modify. That may help point you in the right direction.

Retrieve Redmine application configuration values

Redmine stores application configuration values in a file named config/configuration.yml. To retrieve (get) these configuration values from a plugin, Redmine provides the getter method [], which is defined as a class method on Redmine::Configuration.

Example1:

Consider the following example configuration:

email_delivery:
    delivery_method: :smtp
    smtp_settings:
      address: "myaddress.com" 
      port: 25
      domain: "mydomain.com" 

Then the value of the address configuration key can be retrieved by calling:

Redmine::Configuration['email_delivery']['smtp_settings'][:address]

1 source: RE: how to get at config variables from a plugin

Retrieve Redmine settings values

Redmine stores application settings values in the database. This includes any plugin settings. To interact (get/set) with these settings values from a plugin, Redmine automatically provides getter and setter methods in the form of Setting.some_setting_name and Setting.some_setting_name = "some value", for each setting on the Setting model.

Examples:

  • retrieve the value of the internal (Redmine core) 'welcome text' setting by calling:
    Setting.welcome_text
    
  • retrieve the value of the 'notification_default' setting, as "provided" by the Polls plugin as documented in the Plugin Tutorial, by calling:
    Setting.plugin_polls['notification_default']
    

It is not recommended to manually modify (set) settings values from a plugin. Instead, set these values via the provided UI's.

Require a certain Redmine version

Sometimes plugins require a specific feature implemented in the Redmine core or the plugin overrides a specific view which requires you to control on which (specific) versions of Redmine the plugin can be installed to assure that the required core is available. Such prevents a lot of issues regarding plugin-compatibility.

The above can be accomplished by utilizing the requires_redmine method (see source:/trunk/lib/redmine/plugin.rb@19983#L227). Utilisation of the method provides an easy, reliable way to create plugins that require a specific version of Redmine and which are setup to stop Redmine with a message about a non-supported version if the version-requirement is not met.

Require a certain Redmine plugin version

Sometimes plugins require a specific feature implemented in another Redmine plugin or even a feature that is implemented in a specific version of another plugin which requires you to control dependencies on which the plugin relies before it can be installed to assure that the required plugin (version) is available. Such prevents a lot of issues regarding (inter) plugin-compatibility.

The above can be accomplished by utilizing the requires_redmine_plugin method (see source:/trunk/lib/redmine/plugin.rb@19983#L274). Utilisation of the method provides an easy, reliable way to create plugins that require a specific (version of a) Redmine plugin and which are setup to stop Redmine with a message about a non-supported version if the version-requirement is not met.