The fourth parameter of add_event_handler function was used to tell the number of parameters which will be transmitted to the callback. This is no longer used: all parameters given to trigger_change or trigger_notify are always transmitted to all callback.

But the fourth parameter is still used: if a string is given it will be used as a file path included just before the callback (with include_once).

// procedural
add_event_handler('init', 'my_init',
  EVENT_HANDLER_PRIORITY_NEUTRAL,
  MY_PLUGIN_PATH . 'include/callbacks.php'
  );
 
// OOP with static method
add_event_handler('init', array('MyClass', 'init'),
  EVENT_HANDLER_PRIORITY_NEUTRAL,
  MY_PLUGIN_PATH . 'include/myclass.php'
  );

If the 4th parameter is anything else than a string it is ignored.

We introduced a new pattern for maintenance of plugins, this uses a PHP class named after your plugin and define in a maintain.class.php file with the following methods:

/**
 * PLUGINID must be replaced by the directory name of your plugin
 */
class PLUGINID_maintain extends PluginMaintain
{
  function install($plugin_version, &$errors=array()) { ... }
  function activate($plugin_version, &$errors=array()) { ... }
  function update($old_version, $new_version, &$errors=array()) { ... }
  function deactivate() { ... }
  function uninstall() { ... }
}

The update method can be called outside the automatic update process, for example if plugin files are manually replaced with a newer version, this ensure full support on hosts which block auto-update.

The old file maintain.inc.php is still supported and will never be removed.

conf_update_param function has been enhanced:

• if an array or object is provided as a value, it will be serialized and escaped before database insertion
• provide true as third parameter to update the $conf global as well (with unserialized value)
• if you prefer JSON over PHP serial you can provide a custom serializer as fourth parameter

conf_update_param('my_key', $my_array, true,
  create_function('$v', 'return addslashes(json_encode($v));'));
 
// here, $conf['my_key'] == $my_array;

Two utility functions was added: safe_unserialize and safe_json_decode which can be used if you are not sure if the value has already been unserialized or not.

The plugins TokenInput and Chosen have been removed in favor to Selectize.

Use this to load the script:

{combine_script id='jquery.selectize' load='footer' path='themes/default/js/plugins/selectize.min.js'}

The old plugins sources will be removed in further version, your are advised to migrate now.

Selectize comes with two colorschemes, dark and clear loaded conditionally with help of $themeconf['colorscheme'].

Use this to load the CSS:

{combine_css id='jquery.selectize' path="themes/default/js/plugins/selectize.{$themeconf.colorscheme}.css"}

We added a LocalStorage cache for the lists of tags/albums/users/groups. It is used on every core Selectize box and considerably speeds-up loading time of admin pages. Here is how to use it.

Include the script (before or after Selectize):

{combine_script id='LocalStorageCache' load='footer' path='admin/themes/default/js/LocalStorageCache.js'}

Add the HTML element:

<select data-selectize="categories" data-value="{$associated_albums|@json_encode|escape:html}"
        data-default="{$STORAGE_ALBUM}" name="associate[]" multiple>
</select>

$associated_albums must be an array of identifiers for the preselect items. data-default represents a item which can't be removed.

Init the cache:

var categoriesCache = new CategoriesCache({
  serverKey: '{$CACHE_KEYS.categories}',
  serverId: '{$CACHE_KEYS._hash}',
  rootUrl: '{$ROOT_URL}'
});

$CACHE_KEYS array is used to sync the cache with the server, it contains state keys for categories, tags, users and groups.

Init Selectize with the cache:

categoriesCache.selectize(jQuery('[data-selectize=categories]'));

The reusable “add new album” popin (using Colorbox) has obviously been rewritten to use (exclusively) Selectize and the cache.

As before, include the template:

{include file='include/add_album.inc.tpl'}

Add the receiving select and add button:

<select data-selectize="categories" data-value="{$selected_category|@json_encode|escape:html}"
  data-default="first" name="category" style="width:400px"></select>
 
<br>{'... or '|@translate}
<a href="#" data-add-album="category" title="{'create a new album'|translate}">
  {'create a new album'|@translate}</a>

data-add-album value refers to the name of the select.

Apply pwgAddAlbum micro-plugin by providing the cache:

jQuery('[data-add-album]').pwgAddAlbum({ cache: categoriesCache });

The plugin allow external sources like plugins to start their own tour. Check admin.tpl and the files tour.tpl and config.inc.php of the existing tours to get familiar with the system, but here some explanations:

• the launch of a tour is made throught $_GET or $POST_ and require a pwg_token
• $_REQUEST['submited_tour_path'] contains the path to the config.inc.php file, and is relative to root_of_piwigo/plugins/TakeATour/ (e.g. $_GET['submited_tour_path']=../MyPlugin/tour/introduction )
• config.inc.php contains AT LEAST the value of $TOUR_PATH which is the path to the tpl file and which is relativ eto the root of Piwigo (e.g. $TOUR_PATH = PHPWG_PLUGINS_PATH.'MyPlugin/tours/introduction/mytour.tpl';). config.inc.php is loaded before the parsing of the tpl of the tour and in the init event: so it will contains direct code to assign vars to your tpl, and can also contains additionnal add_event_handler. These add_event_handler are currently used as prefilter to add css id as anchors for steps.
• and so the tpl file should be made using the existing tours as examples: the script used is http://bootstraptour.com/ where you can found a doc

Take A Tour loads the js and css needed, you just have to provide a config.inc.php and a tpl file and to load the language (it's recommended using the new option force_fallback like load_language('plugin.lang', PHPWG_PLUGINS_PATH .'MyPlugin/', array('force_fallback'⇒'en_UK')); because empty text means that the step will be skiped)

The plugin allows also the customization of the content of existing tours:

• $conf['enable_synchronization'] is taken into account, no need to worry about that
• but anything else can be changed by simply adding custom language files (see LocalFiles Editor)
• steps in a tour can be skipped by simply emptying the content and title of that step, in the lang file
• tours can be hidden in the admin of Take A Tour with the array $conf['TakeATour_tour_ignored']

With Selectize on search.tpl, we need to know if the theme is rather clear or dark, to load the appropriate CSS file (clear background or dark background). In your themeconf.inc.php, add the “colorscheme”. It can be “dark” or “clear” only. This parameter will be used for other things like colorbox background or guestbook colors… (very useful for plugins)

$themeconf = array(
  'name'  => 'clear',
  'parent' => 'default',
  'colorscheme' => 'clear',
);

We added an option to disable or enable the website field on comment add form. You must wrap the field in a IF block:

{if $comment_add.SHOW_WEBSITE} ... {/if}

{$THUMB_SRC} template variable is not assigned anymore. Use instead {$current.derivatives.thumb→get_url()}

TODO