Plugin Internals » History » Version 12
Eric Jason, 2011-11-21 21:32
1 | 1 | Mischa The Evil | h1. Plugin Internals |
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2 | 1 | Mischa The Evil | |
3 | 1 | Mischa The Evil | {{>toc}} |
4 | 1 | Mischa The Evil | |
5 | 1 | Mischa The Evil | This page will be used as a central place to store information about plugin-development in Redmine. |
6 | 1 | Mischa The Evil | |
7 | 2 | Mischa The Evil | h2. Require a certain Redmine version |
8 | 2 | Mischa The Evil | |
9 | 2 | Mischa The Evil | 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. |
10 | 2 | Mischa The Evil | |
11 | 10 | Igor Zubkov | The above can be accomplished by utilizing the @requires_redmine@-method (see issue #2162 for the implementation discussion and it's actual implementation in r2042). 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. |
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13 | 1 | Mischa The Evil | h2. Overriding the Redmine Core |
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15 | 1 | Mischa The Evil | You can override views but not controllers or models in Redmine. Here's how Redmine/Rails works if you try to override a controller (or model) and a view for a fictional plugin @MyPlugin@: |
16 | 1 | Mischa The Evil | |
17 | 1 | Mischa The Evil | h3. Controllers (or models) |
18 | 1 | Mischa The Evil | |
19 | 1 | Mischa The Evil | # Rails bootstraps and loads all it's framework |
20 | 1 | Mischa The Evil | # Rails starts to load code in the plugins |
21 | 1 | Mischa The Evil | # Rails finds @IssueController@ in MyPlugin and see it defines a @show@ action |
22 | 1 | Mischa The Evil | # Rails loads all the other plugins |
23 | 1 | Mischa The Evil | # Rails then loads the application from _../app_ |
24 | 1 | Mischa The Evil | # Rails finds @IssueController@ again and see it also defines a @show@ action |
25 | 1 | Mischa The Evil | # Rails (or rather Ruby) overwrites the @show@ action from the plugin with the one from _../app_ |
26 | 1 | Mischa The Evil | # Rails finishes loading and serves up requests |
27 | 1 | Mischa The Evil | |
28 | 1 | Mischa The Evil | h3. Views |
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30 | 1 | Mischa The Evil | View loading is very similar but with one small difference (because of Redmine's patch to Engines) |
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32 | 1 | Mischa The Evil | # Rails bootstraps and loads all it's framework |
33 | 1 | Mischa The Evil | # Rails starts to load code in the plugins |
34 | 1 | Mischa The Evil | # Rails finds a views directory in _../vendor/plugins/my_plugin/app/views_ and *pre-pends* it to the views path |
35 | 1 | Mischa The Evil | # Rails loads all the other plugins |
36 | 1 | Mischa The Evil | # Rails then loads the application from _../app_ |
37 | 1 | Mischa The Evil | # Rails finishes loading and serves up requests |
38 | 1 | Mischa The Evil | # Request comes in, and a view needs to be rendered |
39 | 1 | Mischa The Evil | # Rails looks for a matching template and loads the plugin's template since it was *pre-pended* to the views path |
40 | 1 | Mischa The Evil | # Rails renders the plugins'view |
41 | 1 | Mischa The Evil | |
42 | 1 | Mischa The Evil | Due to the fact that it is so easy to extend models and controllers the Ruby way (via including modules), Redmine shouldn't (and doesn't) maintain an API for overriding the core's models and/or controllers. Views on the other hand are tricky (because of Rails magic) so an API for overriding them is way more useful (and thus implemented in Redmine). |
43 | 1 | Mischa The Evil | |
44 | 8 | Igor Zubkov | To override an existing Redmine Core view just create a view file named exactly after the one in _../app/views/_ and Redmine will use it. For example to override the project index page add a file to _../vendor/plugins/my_plugin/app/views/projects/index.html.erb_. |
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46 | 1 | Mischa The Evil | h2. Extending the Redmine Core |
47 | 1 | Mischa The Evil | |
48 | 1 | Mischa The Evil | As explained above: you rarely want to override a model/controller. Instead you should either: |
49 | 1 | Mischa The Evil | * add new methods to a model/controller or |
50 | 1 | Mischa The Evil | * wrap an existing method. |
51 | 1 | Mischa The Evil | |
52 | 1 | Mischa The Evil | h3. Adding a new method |
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54 | 1 | Mischa The Evil | A quick example of *adding a new method* can be found on Eric Davis' "Budget plugin":http://github.com/edavis10/redmine-budget-plugin/blob/5076b1c88b57c2068aa92cdf694769dbd22d061a/lib/issue_patch.rb. Here he added a new method to Issue called @deliverable_subject@ and also declared a relationship. |
55 | 1 | Mischa The Evil | |
56 | 6 | Eric Davis | <pre><code class="ruby"> |
57 | 6 | Eric Davis | module IssuePatch |
58 | 6 | Eric Davis | def self.included(base) # :nodoc: |
59 | 6 | Eric Davis | base.send(:include, InstanceMethods) |
60 | 6 | Eric Davis | end |
61 | 6 | Eric Davis | |
62 | 6 | Eric Davis | module InstanceMethods |
63 | 6 | Eric Davis | # Wraps the association to get the Deliverable subject. Needed for the |
64 | 6 | Eric Davis | # Query and filtering |
65 | 6 | Eric Davis | def deliverable_subject |
66 | 6 | Eric Davis | unless self.deliverable.nil? |
67 | 6 | Eric Davis | return self.deliverable.subject |
68 | 6 | Eric Davis | end |
69 | 6 | Eric Davis | end |
70 | 9 | Igor Zubkov | end |
71 | 6 | Eric Davis | end |
72 | 6 | Eric Davis | </code></pre> |
73 | 6 | Eric Davis | |
74 | 1 | Mischa The Evil | h3. Wrapping an existing method |
75 | 1 | Mischa The Evil | |
76 | 1 | Mischa The Evil | A quick example of *wrapping an existing method* can be found on Eric Davis' "Rate plugin":http://github.com/edavis10/redmine_rate/blob/4666ddb10e1061ca3ef362735d0d264676b99024/lib/rate_users_helper_patch.rb. Here he uses the @alias_method_chain@ to hook into the UsersHelper and wrap the @user_settings_tabs@ method. So when the Redmine Core calls @user_settings_tabs@ the codepath looks like: |
77 | 1 | Mischa The Evil | |
78 | 1 | Mischa The Evil | # Redmine Core calls @UsersHelper#user_settings_tabs@ |
79 | 1 | Mischa The Evil | # @UsersHelper#user_settings_tabs@ runs (which is actually @UsersHelper#user_settings_tabs_with_rate_tab@) |
80 | 1 | Mischa The Evil | # @UsersHelper#user_settings_tabs_with_rate_tab@ calls the original @UsersHelper#user_settings_tabs@ (renamed to @UsersHelper#user_settings_tabs_without_rate_tab@) |
81 | 1 | Mischa The Evil | # The result then has a new Hash added to it |
82 | 1 | Mischa The Evil | # @UsersHelper#user_settings_tabs_with_rate_tab@ returns the combined result to the Redmine core, which is then rendered |
83 | 6 | Eric Davis | |
84 | 6 | Eric Davis | <pre><code class="ruby"> |
85 | 6 | Eric Davis | module RateUsersHelperPatch |
86 | 6 | Eric Davis | def self.included(base) # :nodoc: |
87 | 6 | Eric Davis | base.send(:include, InstanceMethods) |
88 | 6 | Eric Davis | |
89 | 6 | Eric Davis | base.class_eval do |
90 | 6 | Eric Davis | alias_method_chain :user_settings_tabs, :rate_tab |
91 | 6 | Eric Davis | end |
92 | 6 | Eric Davis | end |
93 | 6 | Eric Davis | |
94 | 6 | Eric Davis | module InstanceMethods |
95 | 6 | Eric Davis | # Adds a rates tab to the user administration page |
96 | 6 | Eric Davis | def user_settings_tabs_with_rate_tab |
97 | 6 | Eric Davis | tabs = user_settings_tabs_without_rate_tab |
98 | 6 | Eric Davis | tabs << { :name => 'rates', :partial => 'users/rates', :label => :rate_label_rate_history} |
99 | 6 | Eric Davis | return tabs |
100 | 6 | Eric Davis | end |
101 | 6 | Eric Davis | end |
102 | 6 | Eric Davis | end |
103 | 6 | Eric Davis | </code></pre> |
104 | 1 | Mischa The Evil | |
105 | 11 | Tony Marschall | "@alias_method_chain@":http://apidock.com/rails/ActiveSupport/CoreExtensions/Module/alias_method_chain is a pretty advanced method but it's also really powerful. |
106 | 11 | Tony Marschall | |
107 | 4 | Mischa The Evil | h2. Using Rails callbacks in Redmine plugins |
108 | 4 | Mischa The Evil | |
109 | 4 | Mischa The Evil | When you want to hook into all issues which are saved/created for example, you can better use "Rails callbacks":http://api.rubyonrails.org/classes/ActiveRecord/Callbacks.html instead of Redmine [[Hooks|hooks]]. Main reason for this is that the @:controller_issues_edit_before_save@-hook is not triggered when a new issue is created. |
110 | 4 | Mischa The Evil | For example see the implementation of this in Eric Davis' "Kanban plugin": |
111 | 4 | Mischa The Evil | # http://github.com/edavis10/redmine_kanban/blob/000cf175795c18033caa43082c4e4d0a9f989623/init.rb#L10 |
112 | 4 | Mischa The Evil | # http://github.com/edavis10/redmine_kanban/blob/000cf175795c18033caa43082c4e4d0a9f989623/lib/redmine_kanban/issue_patch.rb#L13 |
113 | 4 | Mischa The Evil | |
114 | 4 | Mischa The Evil | This will make sure that @issue.update_kanban_from_issue@ runs every time an issue is saved (new or updated). |
115 | 4 | Mischa The Evil | |
116 | 4 | Mischa The Evil | If you want to hook into new issues only you can use the @before_create@ callback instead of the @after_save@ callback. If you want to make sure that the issue indeed is saved successfully before your code is executed you could better use the @after_create@-callback. |
117 | 4 | Mischa The Evil | |
118 | 7 | Terence Mill | h2. Hooking in MyPage |
119 | 7 | Terence Mill | |
120 | 7 | Terence Mill | h3. FAQ |
121 | 7 | Terence Mill | |
122 | 7 | Terence Mill | * Why is the drop-down selection for my blocks not localized? The Name of the entry in the drop-dwon box is per convention made of the entry in the locale file of the plugin. This entry must have the same name as the "my site" block filename, e.g. redmine/vendor/plugins/<myplugin_folder>/app/views/my/blocks/<myblocks_view_file_name>.erb. So you need to add a line "<myblocks_view_file_name>: <put here translation for the drop down item in my blocks configuration>" in your locale, e.g redmine/vendor/plugins/<myplugin_folder>/confige/locale/en.yml. |
123 | 7 | Terence Mill | |
124 | 12 | Eric Jason | If this string is not defined in locale file, alyways the filename <myblocks_view_file_name> without extension is made for label in drop-down and "write my essay for me":http://writemyessay4me.com. |
125 | 7 | Terence Mill | |
126 | 7 | Terence Mill | |
127 | 3 | Mischa The Evil | h2. References |
128 | 3 | Mischa The Evil | |
129 | 3 | Mischa The Evil | * http://www.redmine.org/boards/3/topics/show/5121 (Which version of Redmine I need to use your plugin?) |
130 | 3 | Mischa The Evil | * http://www.redmine.org/boards/3/topics/show/4283 (Can a plugin modify the view of the projects page?) |
131 | 3 | Mischa The Evil | * http://www.redmine.org/boards/3/topics/show/4095 (Rails Engines and extending the issue model) |