updated some documentation
[squirrelmail.git] / doc / plugin.txt
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1aaef171 1A FEW NOTES ON THE PLUGIN ARCHITECTURE
2======================================
3
4The plugin architecture of SquirrelMail is designed to make it
5possible to add new features without having to patch SquirrelMail
6itself. At the moment the plugin part of SquirrelMail should be
7considered "alpha" or "beta" quality code.
8
9Until the functionality and code is more stable, be prepared for
10plugins to suddenly stop working.
11
12Functionality like password changing, displaying ads and calendars
13should be possible to add as plugins.
14
15
16The idea
17--------
18
19The idea is to be able to run random code at given places in the
20SquirrelMail code. This random code should then be able to do whatever
21needed to enhance the functionality of SquirrelMail. The places where
22code can be executed are called "hooks".
23
24There are some limitations in what these hooks can do. It is difficult
25to use them to change the layout and to change functionality that
26already is in SquirrelMail.
27
28Some way for the plugins to interact with the help subsystem and
29translations will be provided.
30
31
32The implementation
33------------------
34
35In the main SquirrelMail files the file functions/plugin.php. In
36places where hooks are made available they are executed by calling the
37function do_hook("hookname").
38
39The do_hook traverses the array $squirrelmail_plugin_hooks["hookname"]
40and executes all the functions that are named in that array.
41
42A plugin must reside in a subdirectory in the plugins/ directory. The
43name of the subdirectory is considered the name of the plugin.
44
45To start using a plugin, its name must be added to the $plugins array
46in config.php like this:
47
48 $plugins[0] = "plugin_name";
49
50When a plugin is registered the file plugins/plugin_name/setup.php is
51included and the function squirrelmail_plugin_init_plugin_name is
52called with no parameters.
53
54
55Writing plugins
56---------------
57
58A plugin must consist of at least a file called setup.php. All other
59files the plugin consist of should also be in the plugin directory.
60
61The function squirrelmail_plugin_init_plugin_name is called to
62initalize a plugin. This function could look something like this:
63
64function squirrelmail_plugin_init_demo () {
65 global $squirrelmail_plugin_hooks;
66
67 $squirrelmail_plugin_hooks["generic_header"]["demo"] = "plugin_demo_header";
68 $squirrelmail_plugin_hooks["menuline"]["demo"] = "plugin_demo_menuline";
69}
70
71Note that the SquirrelMail files assume that all other SquirrelMail
72files are available as ../directory/file. This means that if some file
73in the plugin directory is requested, it must do a chdir("..") before
74including any of the standard SquirrelMail files.
6b638171 75
76
a3a95e4a 77Hook Data Passed
78----------------
79Hooks, when executed, are called with one parameter, an array of data
80that is passed to the hook. The first element in the array is the name
81of the hook that is being called. Any other elements in the array are
82dependant on the type of hook that is being called.
83
84Some of the information in the array may be changed. By default, the
85plugins should never change data unless it is documented otherwise.
86
87
6b638171 88List of hooks
89-------------
ef3c69f0 90 generic_header functions/page_header.php
91 menuline functions/page_header.php
92 compose_button_row src/compose.php
93 compose_bottom src/compose.php
b3911477 94 compose_form src/compose.php
ef3c69f0 95 left_main_before src/left_main.php
96 left_main_after src/left_main.php
97 * options_save src/options.php (see note on options)
98 * options_link_and_description src/options.php (see note on options)
99 * options_highlight_bottom src/options_highlight.php
100 * options_personal_bottom src/options_personal.php
101 * options_personal_inside src/options_personal.php
102 * options_personal_save src/options_personal.php
103 * options_display_bottom src/options_display.php
104 * options_display_inside src/options_display.php
3751dc7f 105 * options_display_save src/options_display.php
ef3c69f0 106 * options_folders_bottom src/options_folders.php
107 * options_folders_inside src/options_folders.php
108 * options_folders_save src/options_folders.php
109 logout src/signout.php
110 login_before src/webmail.php
111 login_verified src/webmail.php
112 loading_prefs src/load_prefs.php
113 mailbox_index_before functions/mailbox_display.php
114 mailbox_index_after functions/mailbox_display.php
3751dc7f 115 mailbox_form_before functions/mailbox_display.php
1ffd5e31 116 subject_link functions/mailbox_display.php
ef3c69f0 117 right_main_after_header src/right_main.php
118 right_main_bottom src/right_main.php
119 login_top src/login.php
120 login_bottom src/login.php
441f2d33 121 html_top src/read_body.php
ef3c69f0 122 read_body_top src/read_body.php
123 read_body_bottom src/read_body.php
441f2d33 124 html_bottom src/read_body.php
7137f80f 125 read_body_header src/read_body.php
ef3c69f0 126 search_before_form src/search.php
127 search_after_form src/search.php
128 search_bottom src/search.php
129 help_top src/help.php
130 help_bottom src/help.php
131 help_chapter src/help.php
3937dc89 132 addrbook_html_search_below src/addrbook_search_html.php
ef3c69f0 133 addressbook_bottom src/addressbook.php
a3a95e4a 134 ^ attachment $type0/$type1 functions/mime.php (see note on attachments)
135
06ad27a2 136
ef3c69f0 137(*) Options
138-----------
139There are two ways to do options for your plugin. First, you can incorporate it
140into an existing section of the preferences (Display, Personal, or Folders).
141The second way, you create your own section that they can choose from and it
142displays its own range of options.
143
144
145First: Integrating into existing options
146-----------------------------------------
147There are two hooks you need to use for this one:
148
1491. options_YOUCHOOSE_inside
150 This is the code that goes inside the table for the section you choose. Since
151 it is going inside an existing table, it must be in this form:
152 ------cut here-------
153 <tr>
154 <td>
155 OPTION_NAME
156 </td>
157 <td>
158 OPTION_INPUT
159 </td>
160 </tr>
161 ------cut here-------
162
1632. options_YOUCHOOSE_save
164 This is the code that saves your preferences into the users' preference
165 file. For an example of how to do this, see src/options.php.
166
167
168Second: Create your own section
169-------------------------------
6b638171 170It is possible to create your own options sections with plugins. There are
171three hooks you will need to use.
172
1731. options_link_and_description
174 This creates the link and has a description that are shown on the options
175 page. This should output HTML that looks like this:
176
177 -----cut here-----
178 function my_function() {
179 global $color
180 ?>
181 <table width=50% cellpadding=3 cellspacing=0 border=0 align=center>
182 <tr>
183 <td bgcolor="<? echo $color[9] ?>">
184 <a href="../plugins/YOUR_PLUGIN/YOUR_OPTIONS.php">YOUR OPTIONS NAME</a>
185 </td>
186 </tr>
187 <tr>
188 <td bgcolor="<? echo $color[0] ?>">
189 YOUR DESCRIPTION
190 </td>
191 </tr>
192 </table>
193 <?php
194 }
195 -----cut here-----
196
1972. options_save
198 Here is the code that you need to do to save your options in the
199 preference files or manipulate whatever data you are trying to change
200 through the options section. You can look at options.php for details
201 on how this is to be done.
202
2033. loading_prefs (optional)
204 If you are wanting to save preferences to the preference files, then
205 you need to do this step as well. Otherwise if you are manipulating
206 other data, ignore this step.
207
208 You should put the code in here that loads your preferences back
209 into usable variables. Examples of this can be found in the file
210 src/load_prefs.php
a3a95e4a 211
212
213(^) Attachment Hooks
214--------------------
215When a message has attachments, this hook is called with the MIME types. For
216instance, a .zip file hook is "attachment application/x-zip". The hook should
217probably show a link to do a specific action, such as "Verify" or "View" for a
218.zip file.
219
220This is a breakdown of the data passed in the array to the hook that is called:
221
222 [0] = Hook's name ('attachment text/plain')
223 [1] = Array of links of actions (more below) (Alterable)
224 [2] = Used for returning to mail message (startMessage)
225 [3] = Used for finding message to display (id)
226 [4] = Mailbox name, urlencode()'d (urlMailbox)
227 [5] = Entity ID inside mail message (ent)
228 [6] = Default URL to go to when filename is clicked on (Alterable)
ef30bf50 229 [7] = Filename that is displayed for the attachment
230 [8] = Sent if message was found from a search (where)
231 [9] = Sent if message was found from a search (what)
a3a95e4a 232
233To set up links for actions, you assign them like this:
234
235 $Args[1]['your_plugin_name']['href'] = 'URL to link to';
236 $Args[1]['your_plugin_name']['text'] = 'What to display';
441f2d33 237