From 1.x to 2.0
===============

.. contents:: Contents
   :local:
   :depth: 1

Elgg can be now installed as a composer dependency instead of at document root
------------------------------------------------------------------------------

That means an Elgg site can look something like this:

.. code-block:: text

    settings.php
    vendor/
      elgg/
        elgg/
          engine/
            start.php
          _graphics/
            elgg_sprites.png
    mod/
      blog
      bookmarks
      ...

``elgg_get_root_path`` and ``$CONFIG->path`` will return the path to the application
root directory, which is not necessarily the same as Elgg core's root directory (which
in this case is ``vendor/elgg/elgg/``).

Do not attempt to access the core Elgg from your plugin directly, since you cannot
rely on its location on the filesystem.

In particular, don't try load ``engine/start.php``.

.. code-block:: php

    // Don't do this!
    dirname(__DIR__) . "/engine/start.php";
    
To boot Elgg manually, you can use the class ``Elgg\Application``.

.. code-block:: php

    // boot Elgg in mod/myplugin/foo.php
    require_once dirname(dirname(__DIR__)) . '/vendor/autoload.php';
    \Elgg\Application::start();

However, use this approach sparingly. Prefer :doc:`/guides/routing` instead whenever possible
as that keeps your public URLs and your filesystem layout decoupled.

Also, don't try to access the ``_graphics`` files directly.

.. code-block:: php

    readfile(elgg_get_root_path() . "_graphics/elgg_sprites.png");
    
Use :doc:`/guides/views` instead:

.. code-block:: php

    echo elgg_view('elgg_sprites.png');
    

Cacheable views must have a file extension in their names
---------------------------------------------------------

This requirement makes it possibile for us to serve assets directly
from disk for performance, instead of serving them through PHP.

It also makes it much easier to explore the available cached resources
by navigating to dataroot/views_simplecache and browsing around.

 * Bad: ``my/cool/template``
 * Good: ``my/cool/template.html``

We now cache assets by ``"$viewtype/$view"``, not ``md5("$viewtype|$view")``,
which can result in conflicts between cacheable views that don't have file extensions
to disambiguate files from directories.


Dropped ``jquery-migrate`` and upgraded ``jquery`` to ^2.1.4
------------------------------------------------------------

jQuery 2.x is API-compatible with 1.x, but drops support for IE8-, which Elgg
hasn't supported for some time anyways.

See http://jquery.com/upgrade-guide/1.9/ for how to move off jquery-migrate.

If you'd prefer to just add it back, you can use this code in your plugin's init:

.. code-block:: php

    elgg_register_js('jquery-migrate', elgg_get_simplecache_url('jquery-migrate.js'), 'head');
    elgg_load_js('jquery-migrate');


Also, define a ``jquery-migrate.js`` view containing the contents of the script.

JS and CSS views have been moved out of the js/ and css/ directories
--------------------------------------------------------------------

They also have been given .js and .css extensions respectively if they didn't
already have them:

================= =============
Old view          New view
================= =============
``js/view``       ``view.js``
``js/other.js``   ``other.js``
``css/view``      ``view.css``
``css/other.css`` ``other.css``
``js/img.png``    ``img.png``
================= =============

The main benefit this brings is being able to co-locate related assets.
So a template (``view.php``) can have its CSS/JS dependencies right next to it
(``view.css``, ``view.js``).

Care has been taken to make this change as backwards-compatible as possible,
so you should not need to update any view references right away. However, you are
certainly encouraged to move your JS and CSS views to their new, canonical
locations.

Practically speaking, this carries a few gotchas:

The ``view_vars, $view_name`` and ``view, $view_name`` hooks will operate on the
*canonical* view name:

.. code-block:: php

    elgg_register_plugin_hook_handler('view', 'css/elgg', function($hook, $view_name) {
      assert($view_name == 'elgg.css') // not "css/elgg"
    });
    
Using the ``view, all`` hook and checking for individual views may not work as intended:

.. code-block:: php

    elgg_register_plugin_hook_handler('view', 'all', function($hook, $view_name) {
      // Won't work because "css/elgg" was aliased to "elgg.css"
      if ($view_name == 'css/elgg') {
        // Never executed...
      }
      
      // Won't work because no canonical views start with css/* anymore
      if (strpos($view_name, 'css/') === 0) {
        // Never executed...
      }
    });

Please let us know about any other BC issues this change causes.
We'd like to fix as many as possible to make the transition smooth.

``fxp/composer-asset-plugin`` is now required to install Elgg from source
-------------------------------------------------------------------------

We use ``fxp/composer-asset-plugin`` to manage our browser assets (js, css, html)
with Composer, but it must be installed globally *before installing Elgg* in order
for the ``bower-asset/*`` packages to be recognized. To install it, run:

.. code-block:: sh

    composer global require fxp/composer-asset-plugin

If you don't do this before running ``composer install`` or ``composer create-project``,
you will get an error message:

.. code-block:: sh

    [InvalidArgumentException]
    Package fxp/composer-asset-plugin not found


List of deprecated views and view arguments that have been removed
------------------------------------------------------------------

We dropped support for and/or removed the following views:

 * canvas/layouts/*
 * categories
 * categories/view
 * core/settings/tools
 * embed/addcontentjs
 * footer/analytics (Use page/elements/foot instead)
 * groups/left_column
 * groups/right_column
 * groups/search/finishblurb
 * groups/search/startblurb
 * input/calendar (Use input/date instead)
 * input/datepicker (Use input/date instead)
 * input/pulldown (Use input/select instead)
 * invitefriends/formitems
 * js/admin (Use AMD and ``elgg_require_js`` instead of extending JS views)
 * js/initialise_elgg (Use AMD and ``elgg_require_js`` instead of extending JS views)
 * members/nav
 * metatags (Use the 'head', 'page' plugin hook instead)
 * navigation/topbar_tools
 * navigation/viewtype
 * notifications/subscriptions/groupsform
 * object/groupforumtopic
 * output/calendar (Use output/date instead)
 * output/confirmlink (Use output/url instead)
 * page_elements/contentwrapper
 * page/elements/shortcut_icon (Use the 'head', 'page' plugin hook instead)
 * page/elements/wrapper
 * profile/icon (Use ``elgg_get_entity_icon``)
 * river/object/groupforumtopic/create
 * settings/{plugin}/edit (Use plugins/{plugin}/settings instead)
 * user/search/finishblurb
 * user/search/startblurb
 * usersettings/{plugin}/edit (Use plugins/{plugin}/usersettings instead)
 * widgets/{handler}/view (Use widgets/{handler}/content instead)

We also dropped the following arguments to views:

 * "value" in output/iframe (Use "src" instead)
 * "area2" and "area3" in page/elements/sidebar (Use "sidebar" or view extension instead)
 * "js" in icon views (e.g. icon/user/default)
 * "options" to input/radio and input/checkboxes which aren't key-value pairs
   will no longer be acceptable.


All scripts moved to bottom of page
-----------------------------------

You should test your plugin **with the JavaScript error console visible**. For performance reasons, Elgg no longer
supports ``script`` elements in the ``head`` element or in HTML views. ``elgg_register_js`` will now load *all*
scripts at the end of the ``body`` element.

You must convert inline scripts to :doc:`AMD </guides/javascript>` or to external scripts loaded with
``elgg_load_js``.

Early in the page, Elgg provides a shim of the RequireJS ``require()`` function that simply queues code until
the AMD ``elgg`` and ``jQuery`` modules are defined. This provides a straightforward way to convert many inline
scripts to use ``require()``.

Inline code which will fail because the stack is not yet loaded:

.. code-block:: html

    <script>
    $(function () {
        // code using $ and elgg
    });
    </script>

This should work in Elgg 2.0:

.. code-block:: html

    <script>
    require(['elgg', 'jquery'], function (elgg, $) {
        $(function () {
            // code using $ and elgg
        });
    });
    </script>

Attribute formatter removes keys with underscores
-------------------------------------------------

``elgg_format_attributes()`` (and all APIs that use it) now filter out attributes whose name contains an
underscore. If the attribute begins with ``data-``, however, it will not be removed.

Breadcrumbs
-----------

Breadcrumb display now removes the last item if it does not contain a link. To restore the previous behavior,
replace the plugin hook handler ``elgg_prepare_breadcrumbs`` with your own:

.. code-block:: php

    elgg_unregister_plugin_hook_handler('prepare', 'breadcrumbs', 'elgg_prepare_breadcrumbs');
    elgg_register_plugin_hook_handler('prepare', 'breadcrumbs', 'myplugin_prepare_breadcrumbs');

    function myplugin_prepare_breadcrumbs($hook, $type, $breadcrumbs, $params) {
        // just apply excerpt to titles
        foreach (array_keys($breadcrumbs) as $i) {
            $breadcrumbs[$i]['title'] = elgg_get_excerpt($breadcrumbs[$i]['title'], 100);
        }
        return $breadcrumbs;
    }

Callbacks in Queries
--------------------

Make sure to use only valid *callable* values for "callback" argument/options in the API.

Querying functions will now will throw a ``RuntimeException`` if ``is_callable()`` returns ``false`` for the given
callback value. This includes functions such as ``elgg_get_entities()``, ``get_data()``, and many more.

Comments plugin hook
--------------------

Plugins can now return an empty string from ``'comments',$entity_type`` hook in order to override the default comments component view. To force the default comments component, your plugin must return ``false``. If you were using empty strings to force the default comments view, you need to update your hook handlers to return ``false``.

Container permissions hook
--------------------------

The behavior of the ``container_permissions_check`` hook has changed when an entity is being created: Before 2.0, the hook would be called twice if the entity's container was not the owner. On the first call, the entity's owner would be passed in as ``$params['container']``, which could confuse handlers.

In 2.0, when an entity is created in a container like a group, if the owner is the same as the logged in user (almost always the case), this first check is bypassed. So the ``container_permissions_check`` hook will almost always be called once with ``$params['container']`` being the correct container of the entity.

Creating or deleting a relationship triggers only one event
-----------------------------------------------------------

The "create" and "delete" relationship events are now only fired once, with ``"relationship"`` as the object type.

E.g. Listening for the ``"create", "member"`` or ``"delete", "member"`` event(s) will no longer capture group membership additions/removals. Use the ``"create", "relationship"`` or ``"delete", "relationship"`` events.

Discussion feature has been pulled from groups into its own plugin
------------------------------------------------------------------

The ``object, groupforumtopic`` subtype has been replaced with the
``object, discussion`` subtype. If your plugin is using or altering
the old discussion feature, you should upgrade it to use the new
subtype.

Nothing changes from the group owners' point of view. The discussion
feature is still available as a group tool and all old discussions
are intact.

Dropped login-over-https feature
--------------------------------

For the best security and performance, serve all pages over HTTPS by switching
the scheme in your site's wwwroot to ``https`` at http://yoursite.tld/admin/settings/advanced

.. _migrated-to-pdo:

Elgg has migrated from ext/mysql to PDO MySQL
---------------------------------------------

Elgg now uses a ``PDO_MYSQL`` connection and no longer uses any ext/mysql functions. If you use
``mysql_*`` functions, implicitly relying on an open connection, these will fail.

If your code uses one of the following functions, read below.

- ``execute_delayed_write_query()``
- ``execute_delayed_read_query()``

If you provide a callable ``$handler`` to be called with the results, your handler will now receive a
``\Doctrine\DBAL\Driver\Statement`` object. Formerly this was an ext/mysql ``result`` resource.


Event/Hook calling order may change
-----------------------------------

When registering for events/hooks, the ``all`` keyword for wildcard matching no longer has any effect
on the order that handlers are called. To ensure your handler is called last, you must give it the
highest priority of all matching handlers, or to ensure your handler is called first, you must give
it the lowest priority of all matching handlers.

If handlers were registered with the same priority, these are called in the order they were registered.

To emulate prior behavior, Elgg core handlers registered with the ``all`` keyword have been raised in
priority. Some of these handlers will most likely be called in a different order.

``export/`` URLs are no longer available
----------------------------------------

Elgg no longer provides this endpoint for exposing resource data.

Icons migrated to Font Awesome
------------------------------

Elgg's sprites and most of the CSS classes beginning with ``elgg-icon-``
`have been removed <https://github.com/Elgg/Elgg/pull/8578/files#diff-b3912b37ca7bd6c53a2968ccb6c22a94L22>`_.

Usage of ``elgg_view_icon()`` is backward compatible, but static HTML using the ``elgg-icon``
classes will have to be updated to the new markup.

Increase of z-index value in elgg-menu-site class
-------------------------------------------------

The value of z-index in the elgg-menu-site class has been increased from 1 to 50 to allow for page elements
in the content area to use the z-index property without the "More" site menu's dropdown being displayed
behind these elements. If your plugin/theme overrides the elgg-menu-site class or views/default/elements/navigation.css
please adjust the z-index value in your modified CSS file accordingly.

input/autocomplete view
-----------------------

Plugins that override the ``input/autocomplete`` view will need to include the source URL in the ``data-source`` attribute of the input element, require the new ``elgg/autocomplete`` AMD module, and call its ``init`` method. The 1.x javascript library ``elgg.autocomplete`` is no longer used.

Introduced third-party library for sending email
------------------------------------------------

We are using the excellent ``Zend\Mail`` library to send emails in Elgg 2.0.
There are likely edge cases that the library handles differently than Elgg 1.x.
Take care to test your email notifications carefully when upgrading to 2.0.

Label elements
--------------

The following views received ``label`` elements around some of the input fields. If your plugin/theme overrides these views please check for the new content.

- views/default/core/river/filter.php
- views/default/forms/admin/plugins/filter.php
- views/default/forms/admin/plugins/sort.php
- views/default/forms/login.php

Plugin Aalborg Theme
--------------------

The view ``page/elements/navbar`` now uses a Font Awesome icon for the mobile menu selector instead of an image. The ``bars.png`` image and supporting CSS for the 1.12 rendering has been removed, so update your theme accordingly.

Plugin Likes
------------

Objects are no longer likable by default. To support liking, you can register a handler to permit the annotation,
or more simply register for the hook ``["likes:is_likable", "<type>:<subtype>"]`` and return true. E.g.

.. code-block:: php

    elgg_register_plugin_hook_handler('likes:is_likable', 'object:mysubtype', 'Elgg\Values::getTrue');

Just as before, the ``permissions_check:annotate`` hook is still called and may be used to override default behavior.

Plugin Messages
---------------

If you've removed or replaced the handler function ``messages_notifier`` to hide/alter the inbox icon, you'll instead need to do the
same for the topbar menu handler ``messages_register_topbar``. ``messages_notifier`` is no longer used to add the menu link.

Messages will no longer get the metadata 'msg' for newly created messages. This means you can not rely on that metadata to exist.

Plugin Blog
-----------

The blog pages showing 'Mine' or 'Friends' listings of blogs have been changed to list all the blogs owned by the users (including those created in groups).

Plugin Bookmarks
----------------

The bookmark pages showing 'Mine' or 'Friends' listings of bookmarks have been changed to list all the bookmarks owned by the users (including those created in groups).

Plugin File
-----------

The file pages showing 'Mine' or 'Friends' listings of files have been changed to list all the files owned by the users (including those created in groups).

Removed Classes
---------------

 - ``ElggInspector``
 - ``Notable``
 - ``FilePluginFile``: replace with ``ElggFile`` (or load with ``get_entity()``)

Removed keys available via ``elgg_get_config()``
------------------------------------------------

 - ``allowed_ajax_views``
 - ``dataroot_in_settings``
 - ``externals``
 - ``externals_map``
 - ``i18n_loaded_from_cache``
 - ``language_paths``
 - ``pagesetupdone``
 - ``registered_tag_metadata_names``
 - ``simplecache_enabled_in_settings``
 - ``translations``
 - ``viewpath``
 - ``views``
 - ``view_path``
 - ``viewtype``
 - ``wordblacklist``

Also note that plugins should not be accessing the global ``$CONFIG`` variable except for in ``settings.php``.

Removed Functions
-----------------

 - ``blog_get_page_content_friends`` 
 - ``blog_get_page_content_read`` 
 - ``count_unread_messages()``
 - ``delete_entities()``
 - ``delete_object_entity()``
 - ``delete_user_entity()``
 - ``elgg_get_view_location()``
 - ``elgg_validate_action_url()``
 - ``execute_delayed_query()``
 - ``extend_view()``
 - ``get_db_error()``
 - ``get_db_link()``
 - ``get_entities()``
 - ``get_entities_from_access_id()``
 - ``get_entities_from_access_collection()``
 - ``get_entities_from_annotations()``
 - ``get_entities_from_metadata()``
 - ``get_entities_from_metadata_multi()``
 - ``get_entities_from_relationship()``
 - ``get_filetype_cloud()``
 - ``get_library_files()``
 - ``get_views()``
 - ``is_ip_in_array()``
 - ``list_entities()``
 - ``list_entities_from_annotations()``
 - ``list_group_search()``
 - ``list_registered_entities()``
 - ``list_user_search()``
 - ``load_plugins()``
 - ``menu_item()``
 - ``make_register_object()``
 - ``mysql_*()``: Elgg :ref:`no longer uses ext/mysql<migrated-to-pdo>`
 - ``remove_blacklist()``
 - ``search_for_group()``
 - ``search_for_object()``
 - ``search_for_site()``
 - ``search_for_user()``
 - ``search_list_objects_by_name()``
 - ``search_list_groups_by_name()``
 - ``search_list_users_by_name()``
 - ``set_template_handler()``
 - ``test_ip()``

Removed methods
---------------

 - ``ElggCache::set_variable()``
 - ``ElggCache::get_variable()``
 - ``ElggData::initialise_attributes()``
 - ``ElggData::getObjectOwnerGUID()``
 - ``ElggDiskFilestore::make_directory_root()``
 - ``ElggDiskFilestore::make_file_matrix()``
 - ``ElggDiskFilestore::user_file_matrix()``
 - ``ElggDiskFilestore::mb_str_split()``
 - ``ElggEntity::clearMetadata()``
 - ``ElggEntity::clearRelationships()``
 - ``ElggEntity::clearAnnotations()``
 - ``ElggEntity::getOwner()``
 - ``ElggEntity::setContainer()``
 - ``ElggEntity::getContainer()``
 - ``ElggEntity::getIcon()``
 - ``ElggEntity::setIcon()``
 - ``ElggExtender::getOwner()``
 - ``ElggFileCache::create_file()``
 - ``ElggObject::addToSite()``: parent function in ElggEntity still available
 - ``ElggObject::getSites()``: parent function in ElggEntity still available
 - ``ElggSite::getCollections()``
 - ``ElggUser::addToSite()``: parent function in ElggEntity still available
 - ``ElggUser::getCollections()``
 - ``ElggUser::getOwner()``
 - ``ElggUser::getSites()``: parent function in ElggEntity still available
 - ``ElggUser::listFriends()``
 - ``ElggUser::listGroups()``
 - ``ElggUser::removeFromSite()``: parent function in ElggEntity still available

The following arguments have also been dropped:

 - ``ElggSite::getMembers()``
   - 2: ``$offset``
 - ``elgg_view_entity_list()``
   - 3: ``$offset``
   - 4: ``$limit``
   - 5: ``$full_view``
   - 6: ``$list_type_toggle``
   - 7: ``$pagination``

Removed Plugin Hooks
--------------------

 - ``[display, view]``: See the :ref:`new plugin hook<guides/views#altering-view-output>`.
 
Removed Actions
---------------

 - ``widgets/upgrade``

Removed Views
-------------

 - ``forms/admin/plugins/change_state``
 
Removed View Variables
----------------------

During rendering, the view system no longer injects these into the scope:

 - ``$vars['url']``: replace with ``elgg_get_site_url()``
 - ``$vars['user']``: replace with ``elgg_get_logged_in_user_entity()``
 - ``$vars['config']``: use ``elgg_get_config()`` and ``elgg_set_config()``
 - ``$CONFIG``: use ``elgg_get_config()`` and ``elgg_set_config()``

Also several workarounds for very old views are no longer performed. Make these changes:

 - Set ``$vars['full_view']`` instead of ``$vars['full']``.
 - Set ``$vars['name']`` instead of ``$vars['internalname']``.
 - Set ``$vars['id']`` instead of ``$vars['internalid']``.

Removed libraries
-----------------

 - ``elgg:markdown``: Elgg no longer provides a markdown implementation. You must provide your own.

Specifying View via Properties
------------------------------

The metadata ``$entity->view`` no longer specifies the view used to render in ``elgg_view_entity()``.

Similarly the property ``$annotation->view`` no longer has an effect within ``elgg_view_annotation()``.

Viewtype is static after the initial ``elgg_get_viewtype()`` call
-----------------------------------------------------------------

``elgg_set_viewtype()`` must be used to set the viewtype at runtime. Although Elgg still checks the
``view`` input and ``$CONFIG->view`` initially, this is only done once per request.


Deprecations
------------

It's deprecated to read or write to metadata keys starting with ``filestore::`` on ``ElggFile`` objects. In Elgg 3.0 this metadata will be deleted if it points to the current data root path, so few file objects will have it. Plugins should only use ``ElggFile::setFilestore`` if files need to be stored in a custom location.

.. note:: This is not the only deprecation in Elgg 2.0. Plugin developers should watch their site error logs.
