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New plugin hook: ability to add custom filters to Shaarli search engine
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1 # Plugin system
2
3 ## Developer API
4
5 ### What can I do with plugins?
6
7 The plugin system lets you:
8
9 - insert content into specific places across templates.
10 - alter data before templates rendering.
11 - alter data before saving new links.
12
13
14 ### How can I create a plugin for Shaarli?
15
16 First, chose a plugin name, such as `demo_plugin`.
17
18 Under `plugin` folder, create a folder named with your plugin name. Then create a <plugin_name>.meta file and a <plugin_name>.php file in that folder.
19
20 You should have the following tree view:
21
22 ```
23 | index.php
24 | plugins/
25 |---| demo_plugin/
26 | |---| demo_plugin.meta
27 | |---| demo_plugin.php
28 ```
29
30 ### Plugin initialization
31
32 At the beginning of Shaarli execution, all enabled plugins are loaded. At this point, the plugin system looks for an `init()` function in the <plugin_name>.php to execute and run it if it exists. This function must be named this way, and takes the `ConfigManager` as parameter.
33
34 <plugin_name>_init($conf)
35
36 This function can be used to create initial data, load default settings, etc. But also to set *plugin errors*. If the initialization function returns an array of strings, they will be understand as errors, and displayed in the header to logged in users.
37
38 The plugin system also looks for a `description` variable in the <plugin_name>.meta file, to be displayed in the plugin administration page.
39
40 description="The plugin does this and that."
41
42 ### Understanding hooks
43
44 A plugin is a set of functions. Each function will be triggered by the plugin system at certain point in Shaarli execution.
45
46 These functions need to be named with this pattern:
47
48 ```
49 hook_<plugin_name>_<hook_name>($data, $conf)
50 ```
51
52 Parameters:
53
54 - data: see [$data section](https://shaarli.readthedocs.io/en/master/Plugin-System/#plugins-data)
55 - conf: the `ConfigManager` instance.
56
57 For example, if my plugin want to add data to the header, this function is needed:
58
59 hook_demo_plugin_render_header
60
61 If this function is declared, and the plugin enabled, it will be called every time Shaarli is rendering the header.
62
63
64 ### Plugin's data
65
66 #### Parameters
67
68 Every hook function has a `$data` parameter. Its content differs for each hooks.
69
70 **This parameter needs to be returned every time**, otherwise data is lost.
71
72 return $data;
73
74 #### Special data
75
76 Special additional data are passed to every hook through the
77 `$data` parameter to give you access to additional context, and services.
78
79 Complete list:
80
81 * `_PAGE_` (string): if the current hook is used to render a template, its name is passed through this additional parameter.
82 * `_LOGGEDIN_` (bool): whether the user is logged in or not.
83 * `_BASE_PATH_` (string): if Shaarli instance is hosted under a subfolder, contains the subfolder path to `index.php` (e.g. `https://domain.tld/shaarli/` -> `/shaarli/`).
84 * `_BOOKMARK_SERVICE_` (`BookmarkServiceInterface`): bookmark service instance, for advanced usage.
85
86 Example:
87
88 ```php
89 if ($data['_PAGE_'] === TemplatePage::LINKLIST && $data['LOGGEDIN'] === true) {
90 // Do something for logged in users when the link list is rendered
91 }
92 ```
93
94 #### Filling templates placeholder
95
96 Template placeholders are displayed in template in specific places.
97
98 RainTPL displays every element contained in the placeholder's array. These element can be added by plugins.
99
100 For example, let's add a value in the placeholder `top_placeholder` which is displayed at the top of my page:
101
102 ```php
103 $data['top_placeholder'][] = 'My content';
104 # OR
105 array_push($data['top_placeholder'], 'My', 'content');
106
107 return $data;
108 ```
109
110
111 #### Data manipulation
112
113 When a page is displayed, every variable send to the template engine is passed to plugins before that in `$data`.
114
115 The data contained by this array can be altered before template rendering.
116
117 For example, in linklist, it is possible to alter every title:
118
119 ```php
120 // mind the reference if you want $data to be altered
121 foreach ($data['links'] as &$value) {
122 // String reverse every title.
123 $value['title'] = strrev($value['title']);
124 }
125
126 return $data;
127 ```
128
129 ### Metadata
130
131 Every plugin needs a `<plugin_name>.meta` file, which is in fact an `.ini` file (`KEY="VALUE"`), to be listed in plugin administration.
132
133 Each file contain two keys:
134
135 - `description`: plugin description
136 - `parameters`: user parameter names, separated by a `;`.
137 - `parameter.<PARAMETER_NAME>`: add a text description the specified parameter.
138
139 > Note: In PHP, `parse_ini_file()` seems to want strings to be between by quotes `"` in the ini file.
140
141 ### Register plugin's routes
142
143 Shaarli lets you register custom Slim routes for your plugin.
144
145 To register a route, the plugin must include a function called `function <plugin_name>_register_routes(): array`.
146
147 This method must return an array of routes, each entry must contain the following keys:
148
149 - `method`: HTTP method, `GET/POST/PUT/PATCH/DELETE`
150 - `route` (path): without prefix, e.g. `/up/{variable}`
151 It will be later prefixed by `/plugin/<plugin name>/`.
152 - `callable` string, function name or FQN class's method to execute, e.g. `demo_plugin_custom_controller`.
153
154 Callable functions or methods must have `Slim\Http\Request` and `Slim\Http\Response` parameters
155 and return a `Slim\Http\Response`. We recommend creating a dedicated class and extend either
156 `ShaarliVisitorController` or `ShaarliAdminController` to use helper functions they provide.
157
158 A dedicated plugin template is available for rendering content: `pluginscontent.html` using `content` placeholder.
159
160 > **Warning**: plugins are not able to use RainTPL template engine for their content due to technical restrictions.
161 > RainTPL does not allow to register multiple template folders, so all HTML rendering must be done within plugin
162 > custom controller.
163
164 Check out the `demo_plugin` for a live example: `GET <shaarli_url>/plugin/demo_plugin/custom`.
165
166 ### Understanding relative paths
167
168 Because Shaarli is a self-hosted tool, an instance can either be installed at the root directory, or under a subfolder.
169 This means that you can *never* use absolute paths (eg `/plugins/mything/file.png`).
170
171 If a file needs to be included in server end, use simple relative path:
172 `PluginManager::$PLUGINS_PATH . '/mything/template.html'`.
173
174 If it needs to be included in front end side (e.g. an image),
175 the relative path must be prefixed with special data:
176
177 * if it's a link that will need to be processed by Shaarli, use `_BASE_PATH_`:
178 for e.g. `$data['_BASE_PATH_'] . '/admin/tools`.
179 * if you want to include an asset, you need to add the root URL (base path without `/index.php`, for people using Shaarli without URL rewriting), then use `_ROOT_PATH_`:
180 for e.g
181 `$['_ROOT_PATH_'] . '/' . PluginManager::$PLUGINS_PATH . '/mything/picture.png`.
182
183 Note that special placeholders for CSS and JS files (respectively `css_files` and `js_files`) are already prefixed
184 with the root path in template files.
185
186 ### It's not working!
187
188 Use `demo_plugin` as a functional example. It covers most of the plugin system features.
189
190 If it's still not working, please [open an issue](https://github.com/shaarli/Shaarli/issues/new).
191
192
193 ### Hooks
194
195 | Hooks | Description |
196 | ------------- |:-------------:|
197 | [render_header](#render_header) | Allow plugin to add content in page headers. |
198 | [render_includes](#render_includes) | Allow plugin to include their own CSS files. |
199 | [render_footer](#render_footer) | Allow plugin to add content in page footer and include their own JS files. |
200 | [render_linklist](#render_linklist) | It allows to add content at the begining and end of the page, after every link displayed and to alter link data. |
201 | [render_editlink](#render_editlink) | Allow to add fields in the form, or display elements. |
202 | [render_tools](#render_tools) | Allow to add content at the end of the page. |
203 | [render_picwall](#render_picwall) | Allow to add content at the top and bottom of the page. |
204 | [render_tagcloud](#render_tagcloud) | Allow to add content at the top and bottom of the page, and after all tags. |
205 | [render_taglist](#render_taglist) | Allow to add content at the top and bottom of the page, and after all tags. |
206 | [render_daily](#render_daily) | Allow to add content at the top and bottom of the page, the bottom of each link and to alter data. |
207 | [render_feed](#render_feed) | Allow to do add tags in RSS and ATOM feeds. |
208 | [save_link](#save_link) | Allow to alter the link being saved in the datastore. |
209 | [delete_link](#delete_link) | Allow to do an action before a link is deleted from the datastore. |
210 | [save_plugin_parameters](#save_plugin_parameters) | Allow to manipulate plugin parameters before they're saved. |
211 | [filter_search_entry](#filter_search_entry) | Add custom filters to Shaarli search engine |
212
213
214 #### render_header
215
216 Triggered on every page - allows plugins to add content in page headers.
217
218
219 ##### Data
220
221 `$data` is an array containing:
222
223 - [Special data](#special-data)
224
225 ##### Template placeholders
226
227 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
228
229 List of placeholders:
230
231 - `buttons_toolbar`: after the list of buttons in the header.
232
233 ![buttons_toolbar_example](http://i.imgur.com/ssJUOrt.png)
234
235 - `fields_toolbar`: after search fields in the header.
236
237 > Note: This will only be called in linklist.
238
239 ![fields_toolbar_example](http://i.imgur.com/3GMifI2.png)
240
241
242 #### render_includes
243
244 Triggered on every page - allows plugins to include their own CSS files.
245
246 ##### data
247
248 `$data` is an array containing:
249
250 - [Special data](#special-data)
251
252 ##### Template placeholders
253
254 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
255
256 List of placeholders:
257
258 - `css_files`: called after loading default CSS.
259
260 > Note: only add the path of the CSS file. E.g: `plugins/demo_plugin/custom_demo.css`.
261
262
263 #### render_footer
264
265 Triggered on every page.
266
267 Allow plugin to add content in page footer and include their own JS files.
268
269 ##### data
270
271 `$data` is an array containing:
272
273 - [Special data](#special-data)
274
275 ##### Template placeholders
276
277 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
278
279 List of placeholders:
280
281 - `text`: called after the end of the footer text.
282 - `endofpage`: called at the end of the page.
283
284 ![text_example](http://i.imgur.com/L5S2YEH.png)
285
286 - `js_files`: called at the end of the page, to include custom JS scripts.
287
288 > Note: only add the path of the JS file. E.g: `plugins/demo_plugin/custom_demo.js`.
289
290
291 #### render_linklist
292
293 Triggered when `linklist` is displayed (list of links, permalink, search, tag filtered, etc.).
294
295 It allows to add content at the begining and end of the page, after every link displayed and to alter link data.
296
297 ##### data
298
299 `$data` is an array containing:
300
301 - All templates data, including links.
302 - [Special data](#special-data)
303
304 ##### template placeholders
305
306 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
307
308 List of placeholders:
309
310 - `action_plugin`: next to the button "private only" at the top and bottom of the page.
311
312 ![action_plugin_example](http://i.imgur.com/Q12PWg0.png)
313
314 - `link_plugin`: for every link, between permalink and link URL.
315
316 ![link_plugin_example](http://i.imgur.com/3oDPhWx.png)
317
318 - `plugin_start_zone`: before displaying the template content.
319
320 ![plugin_start_zone_example](http://i.imgur.com/OVBkGy3.png)
321
322 - `plugin_end_zone`: after displaying the template content.
323
324 ![plugin_end_zone_example](http://i.imgur.com/6IoRuop.png)
325
326
327 #### render_editlink
328
329 Triggered when the link edition form is displayed.
330
331 Allow to add fields in the form, or display elements.
332
333 ##### data
334
335 `$data` is an array containing:
336
337 - All templates data.
338 - [Special data](#special-data)
339
340 ##### template placeholders
341
342 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
343
344 List of placeholders:
345
346 - `edit_link_plugin`: after tags field.
347
348 ![edit_link_plugin_example](http://i.imgur.com/5u17Ens.png)
349
350
351 #### render_tools
352
353 Triggered when the "tools" page is displayed.
354
355 Allow to add content at the end of the page.
356
357 ##### data
358
359 `$data` is an array containing:
360
361 - All templates data.
362 - [Special data](#special-data)
363
364 ##### template placeholders
365
366 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
367
368 List of placeholders:
369
370 - `tools_plugin`: at the end of the page.
371
372 ![tools_plugin_example](http://i.imgur.com/Bqhu9oQ.png)
373
374
375 #### render_picwall
376
377 Triggered when picwall is displayed.
378
379 Allow to add content at the top and bottom of the page.
380
381 ##### data
382
383 `$data` is an array containing:
384
385 - All templates data.
386 - [Special data](#special-data)
387
388 ##### template placeholders
389
390 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
391
392 List of placeholders:
393
394 - `plugin_start_zone`: before displaying the template content.
395 - `plugin_end_zone`: after displaying the template content.
396
397 ![plugin_start_end_zone_example](http://i.imgur.com/tVTQFER.png)
398
399
400 #### render_tagcloud
401
402 Triggered when tagcloud is displayed.
403
404 Allow to add content at the top and bottom of the page.
405
406 ##### data
407
408 `$data` is an array containing:
409
410 - All templates data.
411 - [Special data](#special-data)
412
413 ##### Template placeholders
414
415 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
416
417 List of placeholders:
418
419 - `plugin_start_zone`: before displaying the template content.
420 - `plugin_end_zone`: after displaying the template content.
421
422 For each tag, the following placeholder can be used:
423
424 - `tag_plugin`: after each tag
425
426 ![plugin_start_end_zone_example](http://i.imgur.com/vHmyT3a.png)
427
428
429 #### render_taglist
430
431 Triggered when taglist is displayed - allows to add content at the top and bottom of the page.
432
433 ##### data
434
435 `$data` is an array containing:
436
437 - All templates data.
438 - [Special data](#special-data)
439
440 ##### Template placeholders
441
442 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
443
444 List of placeholders:
445
446 - `plugin_start_zone`: before displaying the template content.
447 - `plugin_end_zone`: after displaying the template content.
448
449 For each tag, the following placeholder can be used:
450
451 - `tag_plugin`: after each tag
452
453 #### render_daily
454
455 Triggered when tagcloud is displayed.
456
457 Allow to add content at the top and bottom of the page, the bottom of each link and to alter data.
458
459
460 ##### data
461
462 `$data` is an array containing:
463
464 - All templates data, including links.
465 - [Special data](#special-data)
466
467 ##### Template placeholders
468
469 Items can be displayed in templates by adding an entry in `$data['<placeholder>']` array.
470
471 List of placeholders:
472
473 - `link_plugin`: used at bottom of each link.
474
475 ![link_plugin_example](http://i.imgur.com/hzhMfSZ.png)
476
477 - `plugin_start_zone`: before displaying the template content.
478 - `plugin_end_zone`: after displaying the template content.
479
480
481 #### render_feed
482
483 Triggered when the ATOM or RSS feed is displayed.
484
485 Allow to add tags in the feed, either in the header or for each items. Items (links) can also be altered before being rendered.
486
487 ##### data
488
489 `$data` is an array containing:
490
491 - All templates data, including links.
492 - [Special data](#special-data)
493
494 ##### Template placeholders
495
496 Tags can be added in feeds by adding an entry in `$data['<placeholder>']` array.
497
498 List of placeholders:
499
500 - `feed_plugins_header`: used as a header tag in the feed.
501
502 For each links:
503
504 - `feed_plugins`: additional tag for every link entry.
505
506
507 #### save_link
508
509 Triggered when a link is save (new link or edit).
510
511 Allow to alter the link being saved in the datastore.
512
513 ##### data
514
515 `$data` is an array containing the link being saved:
516
517 - id
518 - title
519 - url
520 - shorturl
521 - description
522 - private
523 - tags
524 - created
525 - updated
526
527 Also [special data](#special-data).
528
529
530 #### delete_link
531
532 Triggered when a link is deleted.
533
534 Allow to execute any action before the link is actually removed from the datastore
535
536 ##### data
537
538 `$data` is an array containing the link being deleted:
539
540 - id
541 - title
542 - url
543 - shorturl
544 - description
545 - private
546 - tags
547 - created
548 - updated
549
550 Also [special data](#special-data).
551
552 #### save_plugin_parameters
553
554 Triggered when the plugin parameters are saved from the plugin administration page.
555
556 Plugins can perform an action every times their settings are updated.
557 For example it is used to update the CSS file of the `default_colors` plugins.
558
559 ##### data
560
561 `$data` input contains the `$_POST` array.
562
563 So if the plugin has a parameter called `MYPLUGIN_PARAMETER`,
564 the array will contain an entry with `MYPLUGIN_PARAMETER` as a key.
565
566 Also [special data](#special-data).
567
568 #### filter_search_entry
569
570 Triggered for *every* bookmark when Shaarli's BookmarkService method `search()` is used.
571 Any custom filter can be added to filter out bookmarks from search results.
572
573 The hook **must** return either:
574 - `true` to keep bookmark entry in search result set
575 - `false` to discard bookmark entry in result set
576
577 > Note: custom filters are called *before* default filters are applied.
578
579 ##### Parameters
580
581 - `Shaarli\Bookmark\Bookmark` object: entry to evaluate
582 - $context `array`: additional information provided depending on what search is currently used,
583 the user request, etc.
584
585 ## Guide for template designers
586
587 ### Plugin administration
588
589 Your theme must include a plugin administration page: `pluginsadmin.html`.
590
591 > Note: repo's template link needs to be added when the PR is merged.
592
593 Use the default one as an example.
594
595 Aside from classic RainTPL loops, plugins order is handle by JavaScript. You can just include `plugin_admin.js`, only if:
596
597 - you're using a table.
598 - you call orderUp() and orderUp() onclick on arrows.
599 - you add data-line and data-order to your rows.
600
601 Otherwise, you can use your own JS as long as this field is send by the form:
602
603 <input type="hidden" name="order_{$key}" value="{$counter}">
604
605 ### Placeholder system
606
607 In order to make plugins work with every custom themes, you need to add variable placeholder in your templates.
608
609 It's a RainTPL loop like this:
610
611 {loop="$plugin_variable"}
612 {$value}
613 {/loop}
614
615 You should enable `demo_plugin` for testing purpose, since it uses every placeholder available.
616
617 ### List of placeholders
618
619 **page.header.html**
620
621 At the end of the menu:
622
623 {loop="$plugins_header.buttons_toolbar"}
624 {$value}
625 {/loop}
626
627 At the end of file, before clearing floating blocks:
628
629 {if="!empty($plugin_errors) && $is_logged_in"}
630 <ul class="errors">
631 {loop="plugin_errors"}
632 <li>{$value}</li>
633 {/loop}
634 </ul>
635 {/if}
636
637 **includes.html**
638
639 At the end of the file:
640
641 ```html
642 {loop="$plugins_includes.css_files"}
643 <link type="text/css" rel="stylesheet" href="{$value}#"/>
644 {/loop}
645 ```
646
647 **page.footer.html**
648
649 At the end of your footer notes:
650
651 ```html
652 {loop="$plugins_footer.text"}
653 {$value}
654 {/loop}
655 ```
656
657 At the end of file:
658
659 ```html
660 {loop="$plugins_footer.js_files"}
661 <script src="{$value}#"></script>
662 {/loop}
663 ```
664
665 **linklist.html**
666
667 After search fields:
668
669 ```html
670 {loop="$plugins_header.fields_toolbar"}
671 {$value}
672 {/loop}
673 ```
674
675 Before displaying the link list (after paging):
676
677 ```html
678 {loop="$plugin_start_zone"}
679 {$value}
680 {/loop}
681 ```
682
683 For every links (icons):
684
685 ```html
686 {loop="$value.link_plugin"}
687 <span>{$value}</span>
688 {/loop}
689 ```
690
691 Before end paging:
692
693 ```html
694 {loop="$plugin_end_zone"}
695 {$value}
696 {/loop}
697 ```
698
699 **linklist.paging.html**
700
701 After the "private only" icon:
702
703 ```html
704 {loop="$action_plugin"}
705 {$value}
706 {/loop}
707 ```
708
709 **editlink.html**
710
711 After tags field:
712
713 ```html
714 {loop="$edit_link_plugin"}
715 {$value}
716 {/loop}
717 ```
718
719 **tools.html**
720
721 After the last tool:
722
723 ```html
724 {loop="$tools_plugin"}
725 {$value}
726 {/loop}
727 ```
728
729 **picwall.html**
730
731 Top:
732
733 ```html
734 <div id="plugin_zone_start_picwall" class="plugin_zone">
735 {loop="$plugin_start_zone"}
736 {$value}
737 {/loop}
738 </div>
739 ```
740
741 Bottom:
742
743 ```html
744 <div id="plugin_zone_end_picwall" class="plugin_zone">
745 {loop="$plugin_end_zone"}
746 {$value}
747 {/loop}
748 </div>
749 ```
750
751 **tagcloud.html**
752
753 Top:
754
755 ```html
756 <div id="plugin_zone_start_tagcloud" class="plugin_zone">
757 {loop="$plugin_start_zone"}
758 {$value}
759 {/loop}
760 </div>
761 ```
762
763 Bottom:
764
765 ```html
766 <div id="plugin_zone_end_tagcloud" class="plugin_zone">
767 {loop="$plugin_end_zone"}
768 {$value}
769 {/loop}
770 </div>
771 ```
772
773 **daily.html**
774
775 Top:
776
777 ```html
778 <div id="plugin_zone_start_picwall" class="plugin_zone">
779 {loop="$plugin_start_zone"}
780 {$value}
781 {/loop}
782 </div>
783 ```
784
785 After every link:
786
787 ```html
788 <div class="dailyEntryFooter">
789 {loop="$link.link_plugin"}
790 {$value}
791 {/loop}
792 </div>
793 ```
794
795 Bottom:
796
797 ```html
798 <div id="plugin_zone_end_picwall" class="plugin_zone">
799 {loop="$plugin_end_zone"}
800 {$value}
801 {/loop}
802 </div>
803 ```
804
805 **feed.atom.xml** and **feed.rss.xml**:
806
807 In headers tags section:
808 ```xml
809 {loop="$feed_plugins_header"}
810 {$value}
811 {/loop}
812 ```
813
814 After each entry:
815 ```xml
816 {loop="$value.feed_plugins"}
817 {$value}
818 {/loop}
819 ```