adding info about display_message.php
[squirrelmail.git] / doc / plugin.txt
99098885 1$Id$
b6522eb5 3In addition to this document, please check out the SquirrelMail
4development FAQ for more information. Also, help writing plugins
9cd2ae7d 5is easily obtained by posting to the squirrelmail-plugins mailing
b2978b37 6list. (See details about mailing lists on the website)
99098885 7
8FAQ ->
b6522eb5 9Plugin Development ->
9cd2ae7d 10
99098885 11
b6522eb5 16The plugin architecture of SquirrelMail is designed to make it possible
17to add new features without having to patch SquirrelMail itself.
18Functionality like password changing, displaying ads and calendars should
9cd2ae7d 19be possible to add as plugins.
1aaef171 20
9cd2ae7d 22The Idea
1aaef171 23--------
25The idea is to be able to run random code at given places in the
26SquirrelMail code. This random code should then be able to do whatever
27needed to enhance the functionality of SquirrelMail. The places where
28code can be executed are called "hooks".
30There are some limitations in what these hooks can do. It is difficult
31to use them to change the layout and to change functionality that
32already is in SquirrelMail.
34Some way for the plugins to interact with the help subsystem and
35translations will be provided.
9cd2ae7d 38The Implementation
1aaef171 39------------------
9cd2ae7d 41The plugin jumping off point in the main SquirrelMail code is in the
42file functions/plugin.php. In places where hooks are made available,
b6522eb5 43they are executed by calling the function do_hook('hookname'). The
44do_hook function then traverses the array
45$squirrelmail_plugin_hooks['hookname'] and executes all the functions
46that are named in that array. Those functions are placed there when
47plugins register themselves with SquirrelMail as discussed below. A
48plugin may add its own internal functions to this array under any
9cd2ae7d 49hook name provided by the SquirrelMail developers.
1aaef171 50
51A plugin must reside in a subdirectory in the plugins/ directory. The
b6522eb5 52name of the subdirectory is considered to be the name of the plugin.
9cd2ae7d 53(The plugin will not function correctly if this is not the case.)
1aaef171 54
55To start using a plugin, its name must be added to the $plugins array
56in config.php like this:
9cd2ae7d 58 $plugins[0] = 'plugin_name';
1aaef171 59
9cd2ae7d 60When a plugin is registered, the file plugins/plugin_name/setup.php is
61included and the function squirrelmail_plugin_init_plugin_name() is
b6522eb5 62called with no parameters. That function is where the plugin may
9cd2ae7d 63register itself against any hooks it wishes to take advantage of.
1aaef171 64
b6522eb5 69All plugins must contain a file called setup.php and must include a
70function called squirrelmail_plugin_init_plugin_name() therein. Since
71including numerous plugins can slow SquirrelMail performance
72considerably, the setup.php file should contain little else. Any
73functions that are registered against plugin hooks should do little
9cd2ae7d 74more than call another function in a different file.
b6522eb5 76Any other files used by the plugin should also be placed in the
77plugin directory (or subdirectory thereof) and should contain the
9cd2ae7d 78bulk of the plugin logic.
1aaef171 79
9cd2ae7d 80The function squirrelmail_plugin_init_plugin_name() is called to
b6522eb5 81initalize a plugin. This function could look something like this (if
9cd2ae7d 82the plugin was named "demo" and resided in the directory plugins/demo/):
1aaef171 83
b6522eb5 84function squirrelmail_plugin_init_demo ()
9cd2ae7d 85{
86 global $squirrelmail_plugin_hooks;
1aaef171 87
9cd2ae7d 88 $squirrelmail_plugin_hooks['generic_header']['demo'] = 'plugin_demo_header';
89 $squirrelmail_plugin_hooks['menuline']['demo'] = 'plugin_demo_menuline';
92Please note that as of SquirrelMail 1.5.0, this function will no longer
93be called at run time and will instead be called only once at configure-
b6522eb5 94time. Thus, the inclusion of any dynamic code (anything except hook
9cd2ae7d 95registration) here is strongly discouraged.
1aaef171 96
9cd2ae7d 97In this example, the "demo" plugin should also have two other functions
98in its setup.php file called plugin_demo_header() and plugin_demo_menuline().
99The first of these might look something like this:
101function plugin_demo_header()
103 include_once(SM_PATH . 'plugins/demo/functions.php');
104 plugin_demo_header_do();
1aaef171 105}
9cd2ae7d 107The function called plugin_demo_header_do() would be in the file called
108functions.php in the demo plugin directory and would contain the plugin's
109core logic for the "generic_header" hook.
112Including Other Files
b6522eb5 115A plugin may need to reference functionality provided in other
9cd2ae7d 116files, and therefore need to include those files. Most of the
117core SquirrelMail functions are already available to your plugin
118unless it has any files that are requested directly by the client
b6522eb5 119browser (custom options page, etc.). In this case, you'll need
9cd2ae7d 120to make sure you include the files you need (see below).
122Note that as of SquirrelMail 1.4.0, all files are accessed using a
123constant called SM_PATH that always contains the relative path to
b6522eb5 124the main SquirrelMail directory. This constant is always available
125for you to use when including other files from the SquirrelMail core,
126your own plugin, or other plugins, should the need arise. If any of
127your plugin files are requested directly from the client browser,
9cd2ae7d 128you will need to define this constant before you do anything else:
130 define('SM_PATH', '../../');
132Files are included like this:
134 include_once(SM_PATH . 'include/validate.php');
136When including files, please make sure to use the include_once() function
b6522eb5 137and NOT include(), require(), or require_once(), since these all are much
138less efficient than include_once() and can have a cumulative effect on
9cd2ae7d 139SquirrelMail performance.
141The files that you may need to include in a plugin will vary greatly
142depending upon what the plugin is designed to do. For files that are
b6522eb5 143requested directly by the client browser, we strongly recommend that
144you include the file include/validate.php, since it will set up the
145SquirrelMail environment automatically. It will ensure the the user
146has been authenticated and is currently logged in, load all user
9cd2ae7d 147preferences, include internationalization support, call stripslashes()
b6522eb5 148on all incoming data (if magic_quotes_gpc is on), and initialize and
149include all other basic SquirrelMail resources and functions. You may
150see other plugins that directly include other SquirrelMail files, but
151that is no longer necessary and is a hold-over from older SquirrelMail
9cd2ae7d 152versions.
6b638171 153
e398ba12 154List of files, that are included by include/validate.php (If SquirrelMail
155version is not listed, files are included from v.1.3.2.):
156 1. class/mime.class.php
157 1.1. class/mime/Rfc822Header.class.php
158 1.2. class/mime/MessageHeader.class.php
159 1.3. class/mime/AddressStructure.class.php
160 1.4. class/mime/Message.class.php
161 1.5. class/mime/SMimeMessage.class.php
162 1.6. class/mime/Disposition.class.php
163 1.7. class/mime/Language.class.php
164 1.8. class/mime/ContentType.class.php
165 2. functions/global.php
166 3. functions/strings.php
167 4. config/config.php
168 4.1. config/config_local.php (from 1.4.0rc1)
169 5. functions/i18n.php
170 5.1. functions/global.php (from 1.4.0)
171 6. functions/auth.php
172 7. include/load_prefs.php
173 7.1. include/validate.php
174 7.2. functions/prefs.php
175 7.3. functions/plugin.php
176 7.3.1. functions/global.php (from 1.4.0 and 1.5.0)
177 7.3.2. functions/prefs.php (from 1.5.1)
178 7.4. functions/constants.php
179 7.5. do_hook('loading_prefs')
180 8. functions/page_header.php
181 8.1. functions/strings.php
182 8.2. functions/html.php
183 8.3. functions/imap_mailbox.php
184 8.3.1. functions/imap_utf7_local.php
185 8.4. functions/global.php
186 9. functions/prefs.php
187 9.1. functions/global.php
188 9.2. $prefs_backend (from 1.4.3rc1 and 1.5.0)
189 functions/db_prefs.php
190 functions/file_prefs.php
de588ce6 191 9.2.1. functions/display_messages.php
192 (loaded only by file_prefs.php)
6b638171 193
9cd2ae7d 194Hook Types: Parameters and Return Values
f4fd89e0 197Hooks, when executed, are called with differing parameters and may or may
198not take return values, all depending on the type of hook being called and
199the context in which it is being used. On the source side (where the hook
200call originates), all hooks have at least one parameter, which is the
201name of the hook. After that, things get complicated.
203 do_hook
204 -------
205 Most hook calls don't pass any data and don't ask for anything back.
206 These always use the do_hook call. A limited number of do_hook calls do
207 pass some extra parameters, in which case your plugin may modify the
208 given data if you do so by reference. It is not necessary to return
209 anything from your function in such a case; modifying the parameter
210 data by reference is what does the job (although the hook call itself
211 (in the source) must grab the return value for this to work). Note
212 that in this case, the parameter to your hook function will be an array,
213 the first element simply being the hook name, followed by any other
214 parameters that may have been included in the actual hook call in the
215 source. Modify parameters with care!
217 do_hook_function
218 ----------------
219 This hook type was intended to be the main hook type used when the
220 source needs to get something back from your plugin. It is somewhat
221 limited in that it will only use the value returned from the LAST
222 plugin registered against the hook. The source for this hook might
223 use the return value for internal purposes, or might expect you to
224 provide text or HTML to be sent to the client browser (you'll have to
225 look at its use in context to understand how you should return values
226 here). The parameters that your hook function gets will be anything
227 you see AFTER the hook name in the actual hook call in the source.
228 These cannot be changed in the same way that the do_hook parameters
229 can be.
231 concat_hook_function
232 --------------------
233 This is a newer hook type meant to address the shortcomings of
234 do_hook_function; specifically in that it uses the return values of
235 all plugins registered against the hook. In order to do so, the
236 return value is assumed to be a string, which is just piled on top
237 of whatever it got from the other plugins working on the same hook.
238 Again, you'll have to inspect the source code to see how such data
239 is put to use, but most of the time, it is used to create a string
240 of HTML to be inserted into the output page. The parameters that
241 your hook function will get are the same as for the do_hook_function;
242 they are anything AFTER the hook name in the actual hook call in the
243 source.
efea59ed 245 boolean_hook_function
246 ---------------------
f4fd89e0 247 The newest of the SquirrelMail hooks, this type is used to let all
248 plugins registered against the hook to "vote" for some action. What
249 that action is is entirely dependent on how the hook is used in the
250 source (look for yourself). Plugins make their "vote" by returning
251 TRUE or FALSE. This hook may be configured to "tally votes" in one
252 of three ways. This configuration is done with the third parameter
253 in the hook call in the source:
254 > 0 -- Any one or more TRUEs will override any FALSEs
255 < 0 -- Any one or more FALSEs will override any TRUEs
256 = 0 -- Majority wins. Ties are broken in this case with
257 the last parameter in the hook call in the source.
258 Your hook function will get the second paramter in the hook call in
259 the source as its parameter (this might be an array if multiple values
260 need to be passed).
a3a95e4a 261
f4fd89e0 262See below for further discussion of special hook types and the values
a3a95e4a 263
9cd2ae7d 265List of Hooks
6b638171 266-------------
ef3c69f0 267
9cd2ae7d 268This is a list of all hooks currently available in SquirrelMail, ordered
269by file. Note that this list is accurate as of June 17, 2003 (should be
270close to what is contained in release 1.4.1, plus or minus a hook or two),
271but may be out of date soon thereafter. You never know. ;-)
6b638171 272
9cd2ae7d 273 Hook Name Found In Called With(#)
274 --------- -------- --------------
df788686 275 abook_init functions/addressbook.php do_hook
276 abook_add_class functions/addressbook.php do_hook
9cd2ae7d 277 loading_constants functions/constants.php do_hook
54067ccd 278 logout_error functions/display_messages.php do_hook
279 error_box functions/display_messages.php concat_hook
9cd2ae7d 280 get_pref_override functions/file_prefs.php hook_func
281 get_pref functions/file_prefs.php hook_func
282 special_mailbox functions/imap_mailbox.php hook_func
283 % rename_or_delete_folder functions/imap_mailbox.php hook_func
9cd2ae7d 284 mailbox_index_before functions/mailbox_display.php do_hook
285 mailbox_form_before functions/mailbox_display.php do_hook
286 mailbox_index_after functions/mailbox_display.php do_hook
287 check_handleAsSent_result functions/mailbox_display.php do_hook
288 subject_link functions/mailbox_display.php concat_hook
c5aaf57f 289 mailbox_display_buttons functions/mailbox_display.php do_hook
7c788b1c 290 mailbox_display_button_action functions/mailbox_display.php hook_func
9cd2ae7d 291 message_body functions/mime.php do_hook
292 ^ attachment $type0/$type1 functions/mime.php do_hook
9ad17edb 293 attachments_bottom functions/mime.php hook_func
c4115032 294 decode_body functions/mime.php hook_func
9cd2ae7d 295 generic_header functions/page_header.php do_hook
296 menuline functions/page_header.php do_hook
c5aaf57f 297 internal_link functions/page_header.php hook_func
9cd2ae7d 298 loading_prefs include/load_prefs.php do_hook
299 addrbook_html_search_below src/addrbook_search_html.php do_hook
300 addressbook_bottom src/addressbook.php do_hook
301 compose_form src/compose.php do_hook
302 compose_bottom src/compose.php do_hook
303 compose_button_row src/compose.php do_hook
304 compose_send src/compose.php do_hook
305 folders_bottom src/folders.php do_hook
306 help_top src/help.php do_hook
307 help_chapter src/help.php do_hook
308 help_bottom src/help.php do_hook
7022cc97 309 left_main_after_each_folder src/left_main.php concat_hook
9cd2ae7d 310 left_main_before src/left_main.php do_hook
311 left_main_after src/left_main.php do_hook
312 login_cookie src/login.php do_hook
313 login_top src/login.php do_hook
314 login_form src/login.php do_hook
315 login_bottom src/login.php do_hook
9cd2ae7d 316 * optpage_set_loadinfo src/options.php do_hook
317 * optpage_loadhook_personal src/options.php do_hook
318 * optpage_loadhook_display src/options.php do_hook
319 * optpage_loadhook_highlight src/options.php do_hook
320 * optpage_loadhook_folder src/options.php do_hook
321 * optpage_loadhook_order src/options.php do_hook
322 * options_personal_save src/options.php do_hook
323 * options_display_save src/options.php do_hook
324 * options_folder_save src/options.php do_hook
325 * options_save src/options.php do_hook
326 * optpage_register_block src/options.php do_hook
327 * options_link_and_description src/options.php do_hook
328 * options_personal_inside src/options.php do_hook
329 * options_display_inside src/options.php do_hook
330 * options_highlight_inside src/options.php do_hook
331 * options_folder_inside src/options.php do_hook
332 * options_order_inside src/options.php do_hook
333 * options_personal_bottom src/options.php do_hook
334 * options_display_bottom src/options.php do_hook
335 * options_highlight_bottom src/options.php do_hook
336 * options_folder_bottom src/options.php do_hook
337 * options_order_bottom src/options.php do_hook
338 * options_highlight_bottom src/options_highlight.php do_hook
339 & options_identities_process src/options_identities.php do_hook
340 & options_identities_top src/options_identities.php do_hook
341 &% options_identities_renumber src/options_identities.php do_hook
342 & options_identities_table src/options_identities.php concat_hook
343 & options_identities_buttons src/options_identities.php concat_hook
344 message_body src/printer_friendly_bottom.php do_hook
345 read_body_header src/read_body.php do_hook
d44e63d5 346 read_body_menu_top src/read_body.php hook_func
9cd2ae7d 347 read_body_menu_bottom src/read_body.php do_hook
348 read_body_header_right src/read_body.php do_hook
9cd2ae7d 349 read_body_top src/read_body.php do_hook
350 read_body_bottom src/read_body.php do_hook
9cd2ae7d 351 login_before src/redirect.php do_hook
352 login_verified src/redirect.php do_hook
353 generic_header src/right_main.php do_hook
354 right_main_after_header src/right_main.php do_hook
355 right_main_bottom src/right_main.php do_hook
356 search_before_form src/search.php do_hook
357 search_after_form src/search.php do_hook
358 search_bottom src/search.php do_hook
359 logout src/signout.php do_hook
360 webmail_top src/webmail.php do_hook
d44e63d5 361 webmail_bottom src/webmail.php concat_hook
9cd2ae7d 362 logout_above_text src/signout.php concat_hook
8ed1cfc6 363 O info_bottom plugins/info/options.php do_hook
b6522eb5 364
9cd2ae7d 365% = This hook is used in multiple places in the given file
366# = Called with hook type (see below)
367& = Special identity hooks (see below)
368^ = Special attachments hook (see below)
369* = Special options hooks (see below)
8ed1cfc6 370O = optional hook used by plugin
6b638171 371
6b638171 372
9cd2ae7d 373(#) Called With
375Each hook is called using the hook type specified in the list above:
376 do_hook do_hook()
377 hook_func do_hook_function()
378 concat_hook concat_hook_function()
a3a95e4a 379
0f101579 381(&) Identity Hooks
9cd2ae7d 383This set of hooks is passed special information in the array of arguments:
0f101579 384
9cd2ae7d 386
b6522eb5 387 This hook is called at the top of the Identities page, which is
9cd2ae7d 388 most useful when the user has changed any identity settings - this
389 is where you'll want to save any custom information you are keeping
390 for each identity or catch any custom submit buttons that you may
391 have added to the identities page. The arguments to this hook are:
393 [0] = hook name (always "options_identities_process")
394 [1] = should I run the SaveUpdateFunction() (alterable)
396 Obviously, set the second array element to 1/true if you want to
397 trigger SaveUpdateFunction() after the hook is finished - by default,
398 it will not be called.
0f101579 399
9cd2ae7d 401
402 This hook is called when one of the identities is being renumbered,
b6522eb5 403 such as if the user had three identities and deletes the second -
9cd2ae7d 404 this hook would be called with an array that looks like this:
405 ('options_identities_renumber', 2, 1). The arguments to this hook
406 are:
408 [0] = hook name (always "options_identities_renumber")
409 [1] = being renumbered from ('default' or 1 through (# idents) - 1)
410 [2] = being renumbered to ('default' or 1 through (# idents) - 1)
b6522eb5 411
0f101579 412options_identities_table
9cd2ae7d 413
414 This hook allows you to insert additional rows into the table that
415 holds each identity. The arguments to this hook are:
417 [0] = color of table (use it like this in your plugin:
cb3425db 418 <tr bgcolor="<?php echo $info[1]; ?>">
9cd2ae7d 419 [1] = is this an empty section (the one at the end of the list)?
420 [2] = what is the 'post' value? (ident # or empty string if default)
422 You need to return any HTML you would like to add to the table.
423 You could add a table row with code similar to this:
b6522eb5 425 function demo_identities_table(&$args)
9cd2ae7d 426 {
427 return '<tr bgcolor="' . $args[0] . '"><td>&nbsp;</td><td>'
428 . 'YOUR CODE HERE' . '</td></tr>' . "\n";
429 }
b6522eb5 430
0f101579 431options_identities_buttons
9cd2ae7d 432
433 This hook allows you to add a button (or other HTML) to the row of
434 buttons under each identity. The arguments to this hook are:
436 [0] = is this an empty section (the one at the end of the list)?
437 [1] = what is the 'post' value? (ident # or empty string if default)
b6522eb5 439 You need to return any HTML you would like to add here. You could add
9cd2ae7d 440 a button with code similar to this:
442 function demo_identities_button(&$args)
443 {
444 return '<input type="submit" name="demo_button_' . $args[1]
5f75494f 445 . '" value="Press Me" />';
9cd2ae7d 446 }
0f101579 447
a3a95e4a 449(^) Attachment Hooks
451When a message has attachments, this hook is called with the MIME types. For
452instance, a .zip file hook is "attachment application/x-zip". The hook should
453probably show a link to do a specific action, such as "Verify" or "View" for a
9cd2ae7d file. Thus, to register your plugin for .zip attachments, you'd do this
455in setup.php (assuming your plugin is called "demo"):
457 $squirrelmail_plugin_hooks['attachment application/x-zip']['demo']
458 = 'demo_handle_zip_attachment';
a3a95e4a 459
460This is a breakdown of the data passed in the array to the hook that is called:
462 [0] = Hook's name ('attachment text/plain')
9cd2ae7d 463 [1] = Array of links of actions (see below) (alterable)
a3a95e4a 464 [2] = Used for returning to mail message (startMessage)
465 [3] = Used for finding message to display (id)
466 [4] = Mailbox name, urlencode()'d (urlMailbox)
467 [5] = Entity ID inside mail message (ent)
9cd2ae7d 468 [6] = Default URL to go to when filename is clicked on (alterable)
ef30bf50 469 [7] = Filename that is displayed for the attachment
470 [8] = Sent if message was found from a search (where)
471 [9] = Sent if message was found from a search (what)
b6522eb5 472
a3a95e4a 473To set up links for actions, you assign them like this:
b6522eb5 474
9cd2ae7d 475 $Args[1]['<plugin_name>']['href'] = 'URL to link to';
21dab2dc 476 $Args[1]['<plugin_name>']['text'] = _("What to display");
478Note: _("What to display") is explained in the section about
b6522eb5 480
ae2f65a9 481It's also possible to specify a hook as "attachment type0/*",
482for example "attachment text/*". This hook will be executed whenever there's
483no more specific rule available for that type.
9cd2ae7d 485Putting all this together, the demo_handle_zip_attachment() function should
486look like this (note the argument being passed):
57945c53 487
9cd2ae7d 488 function demo_handle_zip_attachment(&$Args)
489 {
490 include_once(SM_PATH . 'plugins/demo/functions.php');
491 demo_handle_zip_attachment_do($Args);
492 }
57945c53 493
9cd2ae7d 494And the demo_handle_zip_attachment_do() function in the
495plugins/demo/functions.php file would typically (but not necessarily)
496display a custom link:
498 function demo_handle_zip_attachment_do(&$Args)
499 {
500 $Args[1]['demo']['href'] = SM_PATH . 'plugins/demo/zip_handler.php?'
b6522eb5 501 . 'passed_id=' . $Args[3] . '&mailbox=' . $Args[4]
9cd2ae7d 502 . '&passed_ent_id=' . $Args[5];
21dab2dc 503 $Args[1]['demo']['text'] = _("Show zip contents");
9cd2ae7d 504 }
506The file plugins/demo/zip_handler.php can now do whatever it needs with the
507attachment (note that this will hand information about how to retrieve the
508source message from the IMAP server as GET varibles).
511(*) Options
513Before you start adding user preferences to your plugin, please take a moment
b6522eb5 514to think about it: in some cases, more options may not be a good thing.
515Having too many options can be confusing. Thinking from the user's
9cd2ae7d 516perspective, will the proposed options actually be used? Will users
517understand what these options are for?
519There are two ways to add options for your plugin. When you only have a few
520options that don't merit an entirely new preferences page, you can incorporate
b6522eb5 521them into an existing section of SquirrelMail preferences (Personal
522Information, Display Preferences, Message Highlighting, Folder Preferences or
523Index Order). Or, if you have an extensive number of settings or for some
9cd2ae7d 524reason need a separate page for the user to interact with, you can create your
525own preferences page.
528Integrating Your Options Into Existing SquirrelMail Preferences Pages
531There are two ways to accomplish the integration of your plugin's settings
b6522eb5 532into another preferences page. The first method is to add the HTML code
9cd2ae7d 533for your options directly to the preferences page of your choice. Although
534currently very popular, this method will soon be deprecated, so avoid it
b6522eb5 535if you can. That said, here is how it works. :) Look for any of the hooks
536named as "options_<pref page>_inside", where <pref page> is "display",
537"personal", etc. For this example, we'll use "options_display_inside" and,
9cd2ae7d 538as above, "demo" as our plugin name:
540 1. In setup.php in the squirrelmail_plugin_init_demo() function:
b6522eb5 542 $squirrelmail_plugin_hooks['options_display_inside']['demo']
9cd2ae7d 543 = 'demo_show_options';
545 Note that there are also hooks such as "options_display_bottom",
546 however, they place your options at the bottom of the preferences
547 page, which is usually not desirable (mostly because they also
548 come AFTER the HTML FORM tag is already closed). It is possible
549 to use these hooks if you want to create your own FORM with custom
550 submission logic.
552 2. Assuming the function demo_show_options() calls another function
553 elsewhere called demo_show_options_do(), that function should have
554 output similar to this (note that you will be inserting code into
555 a table that is already defined with two columns, so please be sure
556 to keep this framework in your plugin):
558 ------cut here-------
559 <tr>
560 <td>
562 </td>
563 <td>
565 </td>
b6522eb5 566 </tr>
9cd2ae7d 567 ------cut here-------
569 Of course, you can place any text where OPTION_NAME is and any input
b6522eb5 570 tags where OPTION_INPUT is.
9cd2ae7d 571
572 3. You will want to use the "options_<pref page>_save" hook (in this case,
573 "options_display_save") to save the user's settings after they have
b6522eb5 574 pressed the "Submit" button. Again, back in setup.php in the
9cd2ae7d 575 squirrelmail_plugin_init_demo() function:
57945c53 576
b6522eb5 577 $squirrelmail_plugin_hooks['options_display_save']['demo']
9cd2ae7d 578 = 'demo_save_options';
57945c53 579
9cd2ae7d 580 4. Assuming the function demo_save_options() calls another function
581 elsewhere called demo_save_options_do(), that function should put
582 the user's settings into permanent storage (see the preferences
583 section below for more information). This example assumes that
584 in the preferences page, the INPUT tag's NAME attribute was set
585 to "demo_option":
587 global $data_dir, $username;
588 sqgetGlobalVar('demo_option', $demo_option);
589 setPref($data_dir, $username, 'demo_option', $demo_option);
592The second way to add options to one of the SquirrelMail preferences page is
593to use one of the "optpage_loadhook_<pref page>" hooks. The sent_subfolders
60eeb409 594plugin has an excellent example of this method. Briefly, this way of adding
9cd2ae7d 595options consists of adding some plugin-specific information to a predefined
596data structure which SquirrelMail then uses to build the HTML input forms
597for you. This is the preferred method of building options lists going forward.
599 1. We'll use the "optpage_loadhook_display" hook to add a new group of
b6522eb5 600 options to the display preferences page. In setup.php in the
9cd2ae7d 601 squirrelmail_plugin_init_demo() function:
b6522eb5 603 $squirrelmail_plugin_hooks['optpage_loadhook_display']['demo']
9cd2ae7d 604 = 'demo_options';
606 2. Assuming the function demo_options() calls another function elsewhere
607 called demo_options_do(), that function needs to add a new key to two
608 arrays, $optpage_data['grps'] and $optpage_data['vals']. The value
609 associated with that key should simply be a section heading for your
610 plugin on the preferences page for the $optpage_data['grps'] array,
b6522eb5 611 and yet another array with all of your plugin's options for the
612 $optpage_data['vals'] array. The options are built as arrays (yes,
9cd2ae7d 613 that's four levels of nested arrays) that specify attributes that are
614 used by SquirrelMail to build your HTML input tags automatically.
615 This example includes just one input element, a SELECT (drop-down)
616 list:
618 global $optpage_data;
619 $optpage_data['grps']['DEMO_PLUGIN'] = 'Demo Options';
620 $optionValues = array();
621 $optionValues[] = array(
622 'name' => 'plugin_demo_favorite_color',
623 'caption' => 'Please Choose Your Favorite Color',
624 'type' => SMOPT_TYPE_STRLIST,
625 'refresh' => SMOPT_REFRESH_ALL,
626 'posvals' => array(0 => 'red',
627 1 => 'blue',
628 2 => 'green',
629 3 => 'orange'),
630 'save' => 'save_plugin_demo_favorite_color'
631 );
632 $optpage_data['vals']['DEMO_PLUGIN'] = $optionValues;
634 The array that you use to specify each plugin option has the following
635 possible attributes:
6976aad7 637 name The name of this setting, which is used not only for
638 the INPUT tag name, but also for the name of this
639 setting in the user's preferences
640 caption The text that prefaces this setting on the preferences
641 page
361d6e1b 642 trailing_text Text that follows a text input or select list input on
643 the preferences page (useful for indicating units,
644 meanings of special values, etc.)
6976aad7 645 type The type of INPUT element, which should be one of:
646 SMOPT_TYPE_STRING String/text input
647 SMOPT_TYPE_STRLIST Select list input
648 SMOPT_TYPE_TEXTAREA Text area input
649 SMOPT_TYPE_INTEGER Integer input
650 SMOPT_TYPE_FLOAT Floating point number input
651 SMOPT_TYPE_BOOLEAN Boolean (yes/no radio buttons)
60eeb409 652 input
6976aad7 653 SMOPT_TYPE_HIDDEN Hidden input (not actually
654 shown on preferences page)
655 SMOPT_TYPE_COMMENT Text is shown (specified by the
656 'comment' attribute), but no
657 user input is needed
658 SMOPT_TYPE_FLDRLIST Select list of IMAP folders
659 refresh Indicates if a link should be shown to refresh part or
660 all of the window (optional). Possible values are:
661 SMOPT_REFRESH_NONE No refresh link is shown
662 SMOPT_REFRESH_FOLDERLIST Link is shown to refresh
663 only the folder list
664 SMOPT_REFRESH_ALL Link is shown to refresh
665 the entire window
b6522eb5 666 initial_value The value that should initially be placed in this
6976aad7 667 INPUT element
668 posvals For select lists, this should be an associative array,
669 where each key is an actual input value and the
670 corresponding value is what is displayed to the user
671 for that list item in the drop-down list
672 value Specify the default/preselected value for this option
673 input
674 save You may indicate that special functionality needs to be
675 used instead of just saving this setting by giving the
b6522eb5 676 name of a function to call when this value would
6976aad7 677 otherwise just be saved in the user's preferences
678 size Specifies the size of certain input items (typically
679 textual inputs). Possible values are:
686 comment For SMOPT_TYPE_COMMENT type options, this is the text
687 displayed to the user
b6522eb5 688 script This is where you may add any additional javascript
6976aad7 689 or other code to the user input
690 post_script You may specify some script (usually Javascript) that
691 will be placed after (outside of) the INPUT tag.
ddb5b25c 692 htmlencoded disables html sanitizing. WARNING - don't use it, if user
693 input is possible in option or use own sanitizing functions.
694 Currently works only with SMOPT_TYPE_STRLIST.
9cd2ae7d 695
60eeb409 696 Note that you do not have to create a whole new section on the options
697 page if you merely want to add a simple input item or two to an options
698 section that already exists. For example, the Display Options page has
699 these groups:
701 0 - General Display Options
702 1 - Mailbox Display Options
703 2 - Message Display and Composition
705 To add our previous input drop-down to the Mailbox Display Options,
706 we would not have to create our own group; just add it to group
707 number one:
709 global $optpage_data;
710 $optpage_data['vals'][1][] = array(
711 'name' => 'plugin_demo_favorite_color',
712 'caption' => 'Please Choose Your Favorite Color',
713 'type' => SMOPT_TYPE_STRLIST,
714 'refresh' => SMOPT_REFRESH_ALL,
715 'posvals' => array(0 => 'red',
716 1 => 'blue',
717 2 => 'green',
718 3 => 'orange'),
719 'save' => 'save_plugin_demo_favorite_color'
720 );
9cd2ae7d 722 3. If you indicated a 'save' attribute for any of your options, you must
723 create that function (you'll only need to do this if you need to do
724 some special processing for one of your settings). The function gets
b6522eb5 725 one parameter, which is an object with mostly the same attributes you
9cd2ae7d 726 defined when you made the option above... the 'new_value' (and possibly
727 'value', which is the current value for this setting) is the most useful
728 attribute in this context:
730 function save_plugin_demo_favorite_color($option)
731 {
732 // if user chose orange, make note that they are really dumb
733 if ($option->new_value == 3)
734 {
735 // more code here as needed
736 }
738 // don't even save this setting if user chose green (old
739 // setting will remain)
740 if ($option->new_value == 2)
741 return;
743 // for all other colors, save as normal
744 save_option($option);
745 }
748Creating Your Own Preferences Page
751It is also possible to create your own preferences page for a plugin. This
b6522eb5 752is particularly useful when your plugin has numerous options or needs to
9cd2ae7d 753offer special interaction with the user (for things such as changing password,
754etc.). Here is an outline of how to do so (again, using the "demo" plugin
b6522eb5 757 1. Add a new listing to the main Options page. Older versions of
9cd2ae7d 758 SquirrelMail offered a hook called "options_link_and_description"
759 although its use is deprecated (and it is harder to use in that
760 it requires you to write your own HTML to add the option). Instead,
761 you should always use the "optpage_register_block" hook where you
762 create a simple array that lets SquirrelMail build the HTML
763 to add the plugin options entry automatically. In setup.php in the
764 squirrelmail_plugin_init_demo() function:
b6522eb5 765
9cd2ae7d 766 $squirrelmail_plugin_hooks['optpage_register_block']['demo']
767 = 'demo_options_block';
769 2. Assuming the function demo_options_block() calls another function
770 elsewhere called demo_options_block_do(), that function only needs
771 to create a simple array and add it to the $optpage_blocks array:
773 global $optpage_blocks;
774 $optpage_blocks[] = array(
775 'name' => 'Favorite Color Settings',
776 'url' => SM_PATH . 'plugins/demo/options.php',
777 'desc' => 'Change your favorite color & find new exciting colors',
778 'js' => FALSE
779 );
781 The array should have four elements:
782 name The title of the plugin's options as it will be displayed on
783 the Options page
784 url The URI that points to your plugin's custom preferences page
785 desc A description of what the preferences page offers the user,
786 displayed on the Options page below the title
787 js Indicates if this option page requires the client browser
788 to be Javascript-capable. Should be TRUE or FALSE.
b6522eb5 790 3. There are two different ways to create the actual preferences page
791 itself. One is to simply write all of your own HTML and other
792 interactive functionality, while the other is to define some data
9cd2ae7d 793 structures that allow SquirrelMail to build your user inputs and save
b6522eb5 794 your data automatically.
9cd2ae7d 795
b6522eb5 796 Building your own page is wide open, and for ideas, you should look at
9cd2ae7d 797 any of the plugins that currently have their own preferences pages. If
b6522eb5 798 you do this, make sure to read step number 4 below for information on
799 saving settings. In order to maintain security, consistant look and
9cd2ae7d 800 feel, internationalization support and overall integrity, there are just
801 a few things you should always do in this case: define the SM_PATH
802 constant, include the file include/validate.php (see the section about
803 including other files above) and make a call to place the standard page
804 heading at the top of your preferences page. The top of your PHP file
805 might look something like this:
807 define('SM_PATH', '../../');
808 include_once(SM_PATH . 'include/validate.php');
809 global $color;
810 displayPageHeader($color, 'None');
812 From here you are on your own, although you are encouraged to do things
813 such as use the $color array to keep your HTML correctly themed, etc.
b6522eb5 815 If you want SquirrelMail to build your preferences page for you,
816 creating input forms and automatically saving users' settings, then
9cd2ae7d 817 you should change the 'url' attribute in the options block you created
818 in step number 2 above to read as follows:
820 'url' => SM_PATH . 'src/options.php?optpage=plugin_demo',
b6522eb5 822 Now, you will need to use the "optpage_set_loadinfo" hook to tell
823 SquirrelMail about your new preferences page. In setup.php in the
9cd2ae7d 824 squirrelmail_plugin_init_demo() function:
b6522eb5 825
9cd2ae7d 826 $squirrelmail_plugin_hooks['optpage_set_loadinfo']['demo']
827 = 'demo_optpage_loadinfo';
829 Assuming the function demo_optpage_loadinfo() calls another function
b6522eb5 830 elsewhere called demo_optpage_loadinfo_do(), that function needs to
831 define values for four variables (make sure you test to see that it
9cd2ae7d 832 is your plugin that is being called by checking the GET variable you
833 added to the url just above):
b6522eb5 834
835 global $optpage, $optpage_name, $optpage_file,
9cd2ae7d 836 $optpage_loader, $optpage_loadhook;
837 if ($optpage == 'plugin_demo')
838 {
839 $optpage_name = "Favorite Color Preferences";
840 $optpage_file = SM_PATH . 'plugins/demo/options.php';
841 $optpage_loader = 'load_optpage_data_demo';
842 $optpage_loadhook = 'optpage_loadhook_demo';
843 }
845 Now you are ready to build all of your options. In the file you
846 indicated for the variable $optpage_file above, you'll need to create
847 a function named the same as the value you used for $optpage_loader
848 above. In this example, the file plugins/demo/options.php should
849 have at least this function in it:
851 function load_optpage_data_demo()
852 {
853 $optpage_data = array();
854 $optpage_data['grps']['DEMO_PLUGIN'] = 'Demo Options';
855 $optionValues = array();
856 $optionValues[] = array(
857 'name' => 'plugin_demo_favorite_color',
858 'caption' => 'Please Choose Your Favorite Color',
859 'type' => SMOPT_TYPE_STRLIST,
860 'refresh' => SMOPT_REFRESH_ALL,
861 'posvals' => array(0 => 'red',
862 1 => 'blue',
863 2 => 'green',
864 3 => 'orange'),
865 'save' => 'save_plugin_demo_favorite_color'
866 );
867 $optpage_data['vals']['DEMO_PLUGIN'] = $optionValues;
868 return $optpage_data;
869 }
871 For a detailed description of how you build these options, please read
872 step number 2 for the second method of adding options to an existing
873 preferences page above. Notice that the only difference here is in the
874 very first and last lines of this function where you are actually
875 creating and returning the options array instead of just adding onto it.
877 That's all there is to it - SquirrelMail will create a preferences page
878 titled as you indicated for $optpage_name above, and other plugins
879 can even add extra options to this new preferences page. To do so,
880 they should use the hook name you specified for $optpage_loadhook above
881 and use the second method for adding option settings to existing
882 preferences pages described above.
884 4. Saving your options settings: if you used the second method in step
885 number 3 above, your settings will be saved automatically (or you can
b6522eb5 886 define special functions to save special settings such as the
9cd2ae7d 887 save_plugin_demo_favorite_color() function in the example described
888 above) and there is probably no need to follow this step. If you
889 created your own preferences page from scratch, you'll need to follow
890 this step. First, you need to register your plugin against the
891 "options_save" hook. In setup.php in the squirrelmail_plugin_init_demo()
892 function:
b6522eb5 893
9cd2ae7d 894 $squirrelmail_plugin_hooks['options_save']['demo']
895 = 'demo_save_options';
897 Assuming the function demo_save_options() calls another function
898 elsewhere called demo_save_options_do(), that function needs to grab
899 all of your POST and/or GET settings values and save them in the user's
900 preferences (for more about preferences, see that section below). Since
b6522eb5 901 this is a generic hook called for all custom preferences pages, you
9cd2ae7d 902 should always set "optpage" as a POST or GET variable with a string that
903 uniquely identifies your plugin:
6fd95361 905 <input type="hidden" name="optpage" value="plugin_demo" />
9cd2ae7d 906
907 Now in your demo_save_options_do() function, do something like this:
909 global $username, $data_dir, $optpage, $favorite_color;
910 if ($optpage == 'plugin_demo')
911 {
912 sqgetGlobalVar('favorite_color', $favorite_color, SQ_FORM);
913 setPref($data_dir, $username, 'favorite_color', $favorite_color);
914 }
b6522eb5 915
916 Note that $favorite_color may not need to be globalized, although
9cd2ae7d 917 experience has shown that some versions of PHP don't behave as expected
918 unless you do so. Even when you use SquirrelMail's built-in preferences
b6522eb5 919 page generation functionality, you may still use this hook, although
920 there should be no need to do so. If you need to do some complex
9cd2ae7d 921 validation routines, note that it might be better to do so in the file
922 you specified as the "$optpage_file" (in our example, that was the
b6522eb5 923 plugins/demo/options.php file), since at this point, you can still
9cd2ae7d 924 redisplay your preferences page. You could put code similar to this
925 in the plugins/demp/options.php file (note that there is no function;
926 this code needs to be executed at include time):
928 global $optmode;
b6522eb5 929 if ($optmode == 'submit')
9cd2ae7d 930 {
931 // do something here such as validation, etc
932 if (you want to redisplay your preferences page)
933 $optmode = '';
934 }
940Saving and retrieving user preferences is very easy in SquirrelMail.
b6522eb5 941SquirrelMail supports preference storage in files or in a database
9cd2ae7d 942backend, however, the code you need to write to manipulate preferences
943is the same in both cases.
b6522eb5 945Setting preferences:
9cd2ae7d 946
947 Setting preferences is done for you if you use the built-in facilities
948 for automatic options construction and presentation (see above). If
949 you need to manually set preferences, however, all you need to do is:
951 global $data_dir, $username;
952 setPref($data_dir, $username, 'pref_name', $pref_value);
954 Where "pref_name" is the key under which the value will be stored
b6522eb5 955 and "pref_value" is a variable that should contain the actual
9cd2ae7d 956 preference value to be stored.
958Loading preferences:
960 There are two approaches to retrieving plugin (or any other) preferences.
961 You can grab individual preferences one at a time or you can add your
b6522eb5 962 plugin's preferences to the routine that loads up user preferences at
9cd2ae7d 963 the beginning of each page request. If you do the latter, making sure
964 to place your preference variables into the global scope, they will be
965 immediately available in all other plugin code. To retrieve a single
966 preference value at any time, do this:
968 global $data_dir, $username;
969 $pref_value = getPref($data_dir, $username, 'pref_name', 'default value');
971 Where "pref_name" is the preference you are retrieving, "default_value"
972 is what will be returned if the preference is not found for this user,
973 and, of course, "pref_value" is the variable that will get the actual
974 preference value.
976 To have all your preferences loaded at once when each page request is
977 made, you'll need to register a function against the "loading_prefs" hook.
978 For our "demo" plugin, in setup.php in the squirrelmail_plugin_init_demo()
979 function:
b6522eb5 980
9cd2ae7d 981 $squirrelmail_plugin_hooks['loading_prefs']['demo']
982 = 'demo_load_prefs';
984 Assuming the function demo_load_prefs() calls another function
985 elsewhere called demo_load_prefs_do(), that function just needs to
986 pull out any all all preferences you'll be needing elsewhere:
988 global $data_dir, $username, $pref_value;
989 $pref_value = getPref($data_dir, $username, 'pref_name', 'default value');
991 Remember to globalize each preference, or this code is useless.
997Although this document may only be available in English, we sure hope that you
998are thinking about making your plugin useful to the thousands of non-English
999speaking SquirrelMail users out there! It is almost rude not to do so, and
1000it isn't much trouble, either. This document will only describe how you can
1001accomplish the internationalization of a plugin. For more general information
1002about PHP and SquirrelMail translation facilities, see:
1006The unofficial way to internationalize a plugin is to put all plugin output
1007into the proper format but to rely on the SquirrelMail translation facilities
1008for all the rest. If the plugin were really to get translated, you'd need
1009to make sure that all output strings for your plugin are either added to or
1010already exist in the main SquirrelMail locale files.
1012The better way to make sure your plugin is translated is to create your own
1013locale files and what is called a "gettext domain" (see the link above for
1014more information).
1016There are three basic steps to getting your plugins internationalized: put
b6522eb5 1017all output into the proper format, switch gettext domains and create locale
9cd2ae7d 1018files.
1020 1. Putting plugin output into the correct format is quite easy. The hard
1021 part is making sure you catch every last echo statement. You need to
1022 echo text like this:
1024 echo _("Hello");
1026 So, even in the HTML segments of your plugin files, you need to do this:
6fd95361 1028 <input type="submit" value="<?php echo _("Submit"); ?>" />
9cd2ae7d 1029
1030 You can put any text you want inside of the quotes (you MUST use double
b6522eb5 1031 quotes!), including HTML tags, etc. What you should think carefully
1032 about is that some languages may use different word ordering, so this
9cd2ae7d 1033 might be problematic:
1035 echo _("I want to eat a ") . $fruitName . _(" before noon");
1037 Because some languages (Japanese, for instance) would need to translate
b6522eb5 1038 such a sentence to "Before noon " . $fruitName . " I want to eat", but
1039 with the format above, they are stuck having to translate each piece
9cd2ae7d 1040 separately. You might want to reword your original sentence:
1042 echo _("This is what I want to eat before noon: ") . $fruitName;
1044 2. By default, the SquirrelMail gettext domain is always in use. That
1045 means that any text in the format described above will be translated
1046 using the locale files found in the main SquirrelMail locale directory.
1047 Unless your plugin produces no output or only output that is in fact
1048 translated under the default SquirrelMail domain, you need to create
1049 your own gettext domain. The PHP for doing so is very simple. At
1050 the top of any file that produces any output, place the following code
1051 (again, using "demo" as the plugin name):
1053 bindtextdomain('demo', SM_PATH . 'plugins/demo/locale');
1054 textdomain('demo');
1056 Now all output will be translated using your own custom locale files.
1057 Please be sure to switch back to the SquirrelMail domain at the end
1058 of the file, or many of the other SquirrelMail files may misbehave:
1060 bindtextdomain('squirrelmail', SM_PATH . 'locale');
1061 textdomain('squirrelmail');
1063 Note that if, in the middle of your plugin file, you use any
1064 SquirrelMail functions that send output to the browser, you'll need
1065 to temporarily switch back to the SquirrelMail domain:
1067 bindtextdomain('squirrelmail', SM_PATH . 'locale');
1068 textdomain('squirrelmail');
1069 displayPageHeader($color, 'None');
1070 bindtextdomain('demo', SM_PATH . 'plugins/demo/locale');
1071 textdomain('demo');
1073 Note that technically speaking, you only need to have one bindtextdomain
1074 call per file, you should always use it before every textdomain call,
1075 since PHP installations without gettext compiled into them will not
1076 function properly if you do not.
1078 3. Finally, you just need to create your own locale. You should create
1079 a directory structure like this in the plugin directory:
1081 demo
1082 |
1083 ------locale
1084 |
1085 ------de_DE
1086 | |
1087 | ------LC_MESSAGES
1088 |
1089 ------ja_JP
1090 |
1091 ------LC_MESSAGES
1093 Create a directories such as de_DE for each language (de_DE is German,
1094 ja_JP is Japanese, etc. - check the SquirrelMail locale directory for
1095 a fairly comprehensive listing). Inside of each LC_MESSAGES directory
1096 you should place two files, one with your translations in it, called
1097 <plugin name>.po (in this case, "demo.po"), and one that is a compiled
1098 version of the ".po" file, called <plugin name>.mo (in this case,
1099 ""). On most linux systems, there is a tool you can use to pull
1100 out most of the strings that you need to have translated from your PHP
1101 files into a sample .po file:
b6522eb5 1103 xgettext --keyword=_ -d <plugin name> -s -C *.php
9cd2ae7d 1104
1105 --keyword option tells xgettext what your strings are enclosed in
1106 -d is the domain of your plugin which should be the plugin's name
1107 -s tells xgettext to sort the results and remove duplicate strings
1108 -C means you are translating a file with C/C++ type syntax (ie. PHP)
1109 *.php is all the files you want translations for
b6522eb5 1111 Note, however, that this will not always pick up all strings, so you
9cd2ae7d 1112 should double-check manually. Of course, it's easiest if you just keep
1113 track of all your strings as you are coding your plugin. Your .po file
1114 will now look something like:
1117 # Copyright (C) YEAR Free Software Foundation, Inc.
1119 #
1120 #, fuzzy
1121 msgid ""
1122 msgstr ""
1123 "Project-Id-Version: PACKAGE VERSION\n"
1124 "POT-Creation-Date: 2003-06-18 11:22-0600\n"
1125 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
1126 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
1127 "Language-Team: LANGUAGE <>\n"
1128 "MIME-Version: 1.0\n"
1129 "Content-Type: text/plain; charset=CHARSET\n"
1130 "Content-Transfer-Encoding: ENCODING\n"
b6522eb5 1131
9cd2ae7d 1132 #: functions.php:45
1133 msgid "Hello"
1134 msgstr ""
b6522eb5 1135
9cd2ae7d 1136 #: functions.php:87
1137 msgid "Favorite Color"
1138 msgstr ""
b6522eb5 1139
9cd2ae7d 1140 You should change the header to look something more like:
1142 # Copyright (c) 1999-2003 The Squirrelmail Development Team
1143 # Roland Bauerschmidt <>, 1999.
df788686 1144 # $Id$
9cd2ae7d 1145 msgid ""
1146 msgstr ""
df788686 1147 "Project-Id-Version: plugin-name version\n"
9cd2ae7d 1148 "POT-Creation-Date: 2003-01-21 19:21+0100\n"
1149 "PO-Revision-Date: 2003-01-21 21:01+0100\n"
1150 "Last-Translator: Juergen Edner <>\n"
1151 "Language-Team: German <>\n"
1152 "MIME-Version: 1.0\n"
1153 "Content-Type: text/plain; charset=ISO-8859-1\n"
1154 "Content-Transfer-Encoding: 8bit\n"
1156 The most important thing to change here is the charset on the next to
1157 last line. You'll want to keep a master copy of the .po file and make
b6522eb5 1158 a copy for each language you have a translation for. You'll need to
9cd2ae7d 1159 translate each string in the .po file:
1161 msgid "Hello"
1162 msgstr "Guten Tag"
b6522eb5 1164 After you're done translating, you can create the .mo file very simply
9cd2ae7d 1165 by running the following command (available on most linux systems):
d2b351d7 1167 msgfmt -o <plugin name>.mo <plugin name>.po
9cd2ae7d 1168
1169 In the case of the "demo" plugin:
d2b351d7 1171 msgfmt -o demo.po
9cd2ae7d 1172
1173 Please be sure that the .po and .mo files both are named exactly the
1174 same as the domain you bound in step 2 above and everything else works
1175 automatically. In SquirrelMail, go to Options -> Display Preferences
1176 and change your Language setting to see the translations in action!
a7532db9 1179
1180Documenting the Code (Optional)
1183If you wish, you can use phpdoc (Javadoc-style) comments, when documenting your
1186If you follow the standards that are followed between Squirrelmail core &
1187plugin developers, the resulted documentation can be included with the rest of
1188the Squirrelmail code & API documentation. Specifically, in the page-level
1189docblock, declare the package to be 'plugins', and the subpackage to be the
1190name of your plugin. For instance:
b6522eb5 1191
a7532db9 1192/**
1193 * demo.php
1194 *
1195 * Copyright (c) 2003 My Name <my-email-address>
1196 * Licensed under the GNU GPL. For full terms see the file COPYING.
1197 *
1198 * @package plugins
1199 * @subpackage demo
1200 */
1202The rest is up to you. Try to follow some common sense and document what is
1203really needed. Documenting the code properly can be a big help not only to
1204yourself, but to those who will take a look at your code, fix the bugs and even
1205improve it, in the true open-source spirit that Squirrelmail was built upon.
1207For more information about phpdocumentor and how to write proper-tagged
1208comments, you are directed at:
1217The SquirrelMail project has some important goals, such as avoiding the
1218use of JavaScript, avoiding non-standard HTML tags, keeping file sizes
1219small and providing the fastest webmail client on the Internet. As such,
1220we'd like it if plugin authors coded with the same goals in mind that the
1221core developers do. Common sense is always a good tool to have in your
b6522eb5 1222programming repertoire, but below is an outline of some standards that we
1223ask you as a plugin developer to meet. Depending upon how far you bend
1224these rules, we may not want to post your plugin on the SquirrelMail
9cd2ae7d 1225website... and of course, no one really wants your efforts to go to waste
1226and for the SquirrelMail community to miss out on a potentially useful
1227plugin, so please try to follow these guidelines as closely as possible.
1230Small setup.php
1233In order for SquirrelMail to remain fast and lean, we are now asking
1234that all plugin authors remove all unnecessary functionality from setup.php
d2b351d7 1235and refactor it into another file. There are a few ways to accomplish
9cd2ae7d 1236this, none of which are difficult. At a minimum, you'll want to have the
1237squirrelmail_plugin_init_<plugin name>() function in setup.php, and naturally,
1238you'll need functions that are merely stubs for each hook that you are using.
1239One (but not the only) way to do it is:
b6522eb5 1241 function squirrelmail_plugin_init_demo()
9cd2ae7d 1242 {
1243 global $squirrelmail_plugin_hooks;
1244 $squirrelmail_plugin_hooks['generic_header']['demo'] = 'plugin_demo_header';
1245 }
1246 function plugin_demo_header()
1247 {
1248 include_once(SM_PATH . 'plugins/demo/functions.php');
1249 plugin_demo_header_do();
1250 }
b6522eb5 1256Q: What is more disappointing to users in France who would make good
9cd2ae7d 1257 use of your plugin than learning that it is written entirely in English?
1258A: Learning that they cannot send you a French translation file for your
1259 plugin.
1261There are thousands of users out there whose native tongue is not English,
1262and when you develop your plugin without going through the three simple steps
b6522eb5 1263needed to internationalize it, you are effectively writing them all off.
9cd2ae7d 1264PLEASE consider internationalizing your plugin!
1267Developing with E_ALL
1270When you are developing your plugin, you should always have error reporting
1271turned all the way up. You can do this by changing two settings in your
1272php.ini and restarting your web server:
799c2046 1274 display_errors = On
9cd2ae7d 1275 error_reporting = E_ALL
1277This way, you'll be sure to see all Notices, Warnings and Errors that your
1278code generates (it's OK, really, it happens to the best of us... except me!).
1279Please make sure to fix them all before you release the plugin.
1b6b1526 1282Compatibility with register_globals=Off
1285Most sensible systems administrators now run their PHP systems with the
1286setting "register_globals" as OFF. This is a prudent security setting,
1287and as the SquirrelMail core code has long since been upgraded to work
1288in such an environment, we are now requiring that all plugins do the same.
1289Compatibility with this setting amounts to little more than explicitly
1290gathering any and all variables you sent from a <form> tag as GET or POST
1291values instead of just assuming that they will be placed in the global
1292scope automatically. There is nothing more to do than this:
1294 global $favorite_color;
1295 sqgetGlobalVar('favorite_color', $favorite_color, SQ_FORM);
9cd2ae7d 1298Extra Blank Lines
1301It may seem innocuous, but if you have any blank lines either before the
1302first <?php tag or after the last ?> tag in any of your plugin files, you
1303you will break SquirrelMail in ways that may seem entirely unrelated. For
1304instance, this will often cause a line feed character to be included with
1305email attachments when they are viewed or downloaded, rendering them useless!
1311When including files, please make sure to use the include_once() function
b6522eb5 1312and NOT include(), require(), or require_once(), since these all are much
1313less efficient than include_once() and can have a cumulative effect on
9cd2ae7d 1314SquirrelMail performance.
1317Version Reporting
1320In order for systems administrators to keep better track of your plugin and
1321get upgrades more efficiently, you are requested to make version information
b6522eb5 1322available to SquirrelMail in a format that it understands. There are two
1323ways to do this. Presently, we are asking that you do both, since we are
1324still in a transition period between the two. This is painless, so please
9cd2ae7d 1325be sure to include it:
1327 1. Create a file called "version" in the plugin directory. That file
1328 should have only two lines: the first line should have the name of
1329 the plugin as named on the SquirrelMail web site (this is often a
b6522eb5 1330 prettified version of the plugin directory name), the second line
9cd2ae7d 1331 must have the version and nothing more. So for our "demo" plugin,
b6522eb5 1332 whose name on the web site might be something like "Demo Favorite
9cd2ae7d 1333 Colors", the file plugins/demo/version should have these two lines:
1335 Demo Favorite Colors
1336 1.0
1338 2. In setup.php, you should have a function called <plugin name>_version().
1339 That function should return the version of your plugin. For the "demo"
1340 plugin, that should look like this:
1342 function demo_version()
1343 {
1344 return '1.0';
1345 }
1348Configuration Files
1351It is common to need a configuration file that holds some variables that
1352are set up at install time. For ease of installation and maintenance, you
1353should place all behavioral settings in a config file, isolated from the
1354rest of your plugin code. A typical file name to use is "config.php". If
1355you are using such a file, you should NOT include a file called "config.php"
b6522eb5 1356in your plugin distribution, but instead a copy of that file called
9cd2ae7d 1357"config.php.sample". This helps systems administrators avoid overwriting
1358the "config.php" files and losing all of their setup information when they
1359upgrade your plugin.
1362Session Variables
1365In the past, there have been some rather serious issues with PHP sessions
1366and SquirrelMail, and certain people have worked long and hard to ensure
1367that these problems no longer occur in an extremely wide variety of OS/PHP/
b6522eb5 1368web server environments. Thus, if you need to place any values into the
1369user's session, there are some built-in SquirrelMail functions that you are
9cd2ae7d 1370strongly encouraged to make use of. Using them also makes your job easier.
1372 1. To place a variable into the session:
b6522eb5 1374 global $favorite_color;
9cd2ae7d 1375 $favoriteColor = 'green';
1376 sqsession_register($favorite_color, 'favorite_color');
1378 Strictly speaking, globalizing the variable shouldn't be necessary,
1379 but certain versions of PHP seem to behave more predictably if you do.
1381 2. To retrieve a variable from the session:
1383 global $favorite_color;
1384 sqgetGlobalVar('favorite_color', $favorite_color, SQ_SESSION);
1386 3. You can also check for the presence of a variable in the session:
1388 if (sqsession_is_registered('favorite_color'))
1389 // do something important
1391 4. To remove a variable from the session:
ea26c996 1393 global $favorite_color;
9cd2ae7d 1394 sqsession_unregister('favorite_color');
ea26c996 1396 Strictly speaking, globalizing the variable shouldn't be necessary,
1397 but certain versions of PHP seem to behave more predictably if you do.
9cd2ae7d 1399
1400Form Variables
b6522eb5 1403You are also encouraged to use SquirrelMail's built-in facilities to
9cd2ae7d 1404retrieve variables from POST and GET submissions. This is also much
1405easier on you and makes sure that all PHP installations are accounted
b6522eb5 1406for (such as those that don't make the $_POST array automatically
9cd2ae7d 1407global, etc.):
1409 global $favorite_color;
1410 sqgetGlobalVar('favorite_color', $favorite_color, SQ_FORM);
1413Files In Plugin Directory
1416There are a few files that you should make sure to include when you build
1417your final plugin distribution:
b6522eb5 1419 1. A copy of the file index.php from the main plugins directory. When
9cd2ae7d 1420 working in your plugin directory, just copy it in like this:
1422 $ cp ../index.php .
1424 This will redirect anyone who tries to browse to your plugin directory
1425 to somewhere more appropriate. If you create other directories under
1426 your plugin directory, you may copy the file there as well to be extra
1427 safe. If you are storing sensitive configuration files or other data
1428 in such a directory, you could even include a .htaccess file with the
b6522eb5 1429 contents "Deny From All" that will disallow access to that directory
9cd2ae7d 1430 entirely (when the target system is running the Apache web server).
1431 Keep in mind that not all web servers will honor an .htaccess file, so
1432 don't depend on it for security. Make sure not to put such a file in
1433 your main plugin directory!
b6522eb5 1435 2. A file that describes your plugin and offers detailed instructions for
1436 configuration or help with troubleshooting, etc. This file is usually
9cd2ae7d 1437 entitled "README". Some useful sections to include might be:
1439 Plugin Name and Author
1440 Current Version
1441 Plugin Features
1442 Detailed Plugin Description
1443 How-to for Plugin Configuration
1444 Change Log
1445 Future Ideas/Enhancements/To Do List
1447 3. A file that explains how to install your plugin. This file is typically
b6522eb5 1448 called "INSTALL". If you do not require any special installation
9cd2ae7d 1449 actions, you can probably copy one from another plugin or use this as
1450 a template:
1452 Installing the Demo Plugin
1453 ==========================
1455 1) Start with untaring the file into the plugins directory.
1456 Here is a example for the 1.0 version of the Demo plugin.
1458 $ cd plugins
1459 $ tar -zxvf demo-1.0-1.4.0.tar.gz
1461 2) Change into the demo directory, copy config.php.sample
1462 to config.php and edit config.php, making adjustments as
1463 you deem necessary. For more detailed explanations about
1464 each of these parameters, consult the README file.
b6522eb5 1465
9cd2ae7d 1466 $ cd demo
1467 $ cp config.php.sample config.php
1468 $ vi config.php
b6522eb5 1469
9cd2ae7d 1471 3) Then go to your config directory and run Choose
1472 option 8 and move the plugin from the "Available Plugins"
1473 category to the "Installed Plugins" category. Save and exit.
b6522eb5 1474
9cd2ae7d 1475 $ cd ../../config/
1476 $ ./
b6522eb5 1477
9cd2ae7d 1478
1479 Upgrading the Demo Plugin
1480 =========================
1482 1) Start with untaring the file into the plugins directory.
1483 Here is a example for the 3.1 version of the demo plugin.
1485 $ cd plugins
1486 $ tar -zxvf demo-3.1-1.4.0.tar.gz
1489 2) Change into the demo directory, check your config.php
1490 file against the new version, to see if there are any new
1491 settings that you must add to your config.php file.
1493 $ diff -Nau config.php config.php.sample
b6522eb5 1494
9cd2ae7d 1495 Or simply replace your config.php file with the provided sample
1496 and reconfigure the plugin from scratch (see step 2 under the
1497 installation procedure above).
1503Whenever new versions of SquirrelMail are released, there is always a
1504considerable lag time before it is widely adopted. During that transitional
1505time, especially when the new SquirrelMail version contains any architectural
1506and/or functional changes, plugin developers are put in a unique and very
1507difficult position. That is, there will be people running both the old and
b6522eb5 1508new versions of SquirrelMail who want to use your plugin, and you will
9cd2ae7d 1509probably want to accomodate them both.
1511The easiest way to keep both sides happy is to keep two different versions
1512of your pluign up to date, one that runs under the older SquirrelMail, and
1513one that requires the newest SquirrelMail. This is inconvenient, however,
1514especially if you are continuing to develop the plugin. Depending on the
1515changes the SquirrelMail has implemented in the new version, you may be able
1516to include code that can auto-sense SquirrelMail version and make adjustments
b6522eb5 1517on the fly. There is a function available to you for determining the
9cd2ae7d 1518SquirrelMail version called check_sm_version() and it can be used as such:
1520 check_sm_version(1, 4, 0)
1522This will return TRUE if the SquirrelMail being used is at least 1.4.0, and
1523FALSE otherwise.
1525As this document is written, we are in a transition period between versions
15261.2.11 and 1.4.0. There is a plugin called "Compatibilty" that is intended
1527for use by plugin authors so they can develop one version of their plugin
1528and seamlessly support both 1.2.x and 1.4.x SquirrelMail installations. For
1529more information about how to use the "Compatibility" plugin, download it and
1530read its README file or see:
1538It's impossible to foresee all of the places where hooks might be useful
1539(it's also impossible to put in hooks everywhere!), so you might need to
1540negotiate the insertion of a new hook to make your plugin work. In order
1541to do so, you should post such a request to the squirrelmail-devel mailing
1548As long as you've consulted the list of plugin standards and done your
1549best to follow them, there's little standing in the way of great fame as an
1550official SquirrelMail plugin developer.
1552 1. Make a distribution file. There is a convenient Perl script in
1553 the plugins directory that will help you do this:
1555 -v demo 1.0 1.4.0
1557 -v is optional and indicates that the script should run in verbose mode
1558 demo is the name of your plugin
1559 1.0 is the version of your plugin
1560 1.4.0 is the version of SquirrelMail that is required to run your plugin
b6522eb5 1562 You can also create the distribution file manually in most *nix
1563 environments by running this command from the plugins directory (NOT
9cd2ae7d 1564 your plugin directory):
1566 $ tar czvf demo-1.0-1.4.0.tar.gz demo
1568 Where "demo" is the name of your plugin, "1.0" is the version of
1569 your plugin, and "1.4.0" is the version of SquirrelMail required
1570 to use your plugin.
1572 2. Consult the SquirrelMail web site for contact information for the
b6522eb5 1573 Plugins Team Leaders, to whom you should make your request. If they
1574 do not respond, you should feel free to ask for help contacting them
9cd2ae7d 1575 on the squirrelmail-plugins mailing list.