* Added the section about validate.php
[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
0e8c1c9a 95 compose_send src/compose.php
ef3c69f0 96 left_main_before src/left_main.php
97 left_main_after src/left_main.php
98 * options_save src/options.php (see note on options)
99 * options_link_and_description src/options.php (see note on options)
100 * options_highlight_bottom src/options_highlight.php
101 * options_personal_bottom src/options_personal.php
102 * options_personal_inside src/options_personal.php
103 * options_personal_save src/options_personal.php
104 * options_display_bottom src/options_display.php
105 * options_display_inside src/options_display.php
3751dc7f 106 * options_display_save src/options_display.php
ef3c69f0 107 * options_folders_bottom src/options_folders.php
108 * options_folders_inside src/options_folders.php
109 * options_folders_save src/options_folders.php
110 logout src/signout.php
111 login_before src/webmail.php
112 login_verified src/webmail.php
113 loading_prefs src/load_prefs.php
114 mailbox_index_before functions/mailbox_display.php
115 mailbox_index_after functions/mailbox_display.php
3751dc7f 116 mailbox_form_before functions/mailbox_display.php
1ffd5e31 117 subject_link functions/mailbox_display.php
ef3c69f0 118 right_main_after_header src/right_main.php
119 right_main_bottom src/right_main.php
120 login_top src/login.php
121 login_bottom src/login.php
441f2d33 122 html_top src/read_body.php
ef3c69f0 123 read_body_top src/read_body.php
124 read_body_bottom src/read_body.php
441f2d33 125 html_bottom src/read_body.php
7137f80f 126 read_body_header src/read_body.php
ef3c69f0 127 search_before_form src/search.php
128 search_after_form src/search.php
129 search_bottom src/search.php
130 help_top src/help.php
131 help_bottom src/help.php
132 help_chapter src/help.php
3937dc89 133 addrbook_html_search_below src/addrbook_search_html.php
ef3c69f0 134 addressbook_bottom src/addressbook.php
a3a95e4a 135 ^ attachment $type0/$type1 functions/mime.php (see note on attachments)
136
06ad27a2 137
ef3c69f0 138(*) Options
139-----------
140There are two ways to do options for your plugin. First, you can incorporate it
141into an existing section of the preferences (Display, Personal, or Folders).
142The second way, you create your own section that they can choose from and it
143displays its own range of options.
144
145
146First: Integrating into existing options
147-----------------------------------------
148There are two hooks you need to use for this one:
149
1501. options_YOUCHOOSE_inside
151 This is the code that goes inside the table for the section you choose. Since
152 it is going inside an existing table, it must be in this form:
153 ------cut here-------
154 <tr>
155 <td>
156 OPTION_NAME
157 </td>
158 <td>
159 OPTION_INPUT
160 </td>
161 </tr>
162 ------cut here-------
163
1642. options_YOUCHOOSE_save
165 This is the code that saves your preferences into the users' preference
166 file. For an example of how to do this, see src/options.php.
167
168
169Second: Create your own section
170-------------------------------
6b638171 171It is possible to create your own options sections with plugins. There are
172three hooks you will need to use.
173
1741. options_link_and_description
175 This creates the link and has a description that are shown on the options
57945c53 176 page. This should output HTML that looks like this. Make sure to read
177 the section on outputting your own pages.
6b638171 178
179 -----cut here-----
57945c53 180 function my_plugin_name_my_function() {
6b638171 181 global $color
182 ?>
183 <table width=50% cellpadding=3 cellspacing=0 border=0 align=center>
184 <tr>
185 <td bgcolor="<? echo $color[9] ?>">
186 <a href="../plugins/YOUR_PLUGIN/YOUR_OPTIONS.php">YOUR OPTIONS NAME</a>
187 </td>
188 </tr>
189 <tr>
190 <td bgcolor="<? echo $color[0] ?>">
191 YOUR DESCRIPTION
192 </td>
193 </tr>
194 </table>
195 <?php
196 }
197 -----cut here-----
198
1992. options_save
200 Here is the code that you need to do to save your options in the
201 preference files or manipulate whatever data you are trying to change
202 through the options section. You can look at options.php for details
203 on how this is to be done.
204
2053. loading_prefs (optional)
206 If you are wanting to save preferences to the preference files, then
207 you need to do this step as well. Otherwise if you are manipulating
208 other data, ignore this step.
209
210 You should put the code in here that loads your preferences back
211 into usable variables. Examples of this can be found in the file
212 src/load_prefs.php
a3a95e4a 213
214
215(^) Attachment Hooks
216--------------------
217When a message has attachments, this hook is called with the MIME types. For
218instance, a .zip file hook is "attachment application/x-zip". The hook should
219probably show a link to do a specific action, such as "Verify" or "View" for a
220.zip file.
221
222This is a breakdown of the data passed in the array to the hook that is called:
223
224 [0] = Hook's name ('attachment text/plain')
225 [1] = Array of links of actions (more below) (Alterable)
226 [2] = Used for returning to mail message (startMessage)
227 [3] = Used for finding message to display (id)
228 [4] = Mailbox name, urlencode()'d (urlMailbox)
229 [5] = Entity ID inside mail message (ent)
230 [6] = Default URL to go to when filename is clicked on (Alterable)
ef30bf50 231 [7] = Filename that is displayed for the attachment
232 [8] = Sent if message was found from a search (where)
233 [9] = Sent if message was found from a search (what)
a3a95e4a 234
235To set up links for actions, you assign them like this:
236
237 $Args[1]['your_plugin_name']['href'] = 'URL to link to';
238 $Args[1]['your_plugin_name']['text'] = 'What to display';
441f2d33 239
57945c53 240
241Outputting Your Own Pages
242-------------------------
243
244Often, when you want to provide your own customized options screen or create
245another web page instead of just using standard hooks, you will be creating
246your own .php files. An example of this is the attachment_common plugin's
247image.php file.
248
249To make sure that security is maintained and standards are followed, the top
250of your PHP script should look very similar to this:
251
252 <?PHP
253 /* This is my php file.
254 * description goes here.
255 */
256
257 chdir('..');
258 include('../src/validate.php');
259
260The validate.php script will include internationalization support,
261config.php variables, strings.php functions, and also authenticate that the
262user is truly logged in. Validate.php also calls stripslashes() on incoming
263data (if gpc_magic_quotes() is on). You should never need to worry about
264that stuff again. As a warning, this has only really been ironed out in
2651.1.1. If you create/modify a plugin to follow these rules, you must
266mention that it requires SquirrelMail 1.1.1 or later.
267
268After that, if you need further functions, just use
269
270 include('../functions/filename.php');
271
272in your script. Since 1.0.5, it was no longer necessary (nor recommended)
273to use the "if (! isset($filename_php))" syntax.