This files describes API changes in /theme/* themes,
information provided here is intended especially for theme designer.

=== 3.8 ===

* Moodle does not produce chunked CSS anymore, instead an unique css fils is generated and served (MDL-55751). This implies:
  * css_chunk_by_selector_count() has been removed.
  * css_store_css(), theme_styles_get_filename() and theme_styles_get_etag() don't accept any chunk-related param anymore.
* The PHP Less compilier has now been removed from the core library.
  Please consider migrating your theme to use SCSS.
* It is now possible to use sub-directories when creating mustache templates.
  The standard rules for Level 2 namespaces also apply to templates.
  The sub-directory used must be either an valid component, or placed inside a 'local' directory to ensure that it does not conflict with other components.

    The following are all valid template names and locations in your theme:
      theme_themename/columns2: theme/[themename]/templates/columns2.mustache
      theme_themename/local/layouts/columns2: theme/[themename]/templates/local/layouts/columns2.mustache

    The following are core templates, locations, and override locations in your theme:
      core/modal: lib/templates/modal.mustache => theme/[themename]/templates/core/modal.mustache
      mod_forum/forum_post: mod/forum/templates/forum_post.mustache => theme/[themename]/templates/mod_forum/forum_post.mustache
      mod_forum/local/post/user: mod/forum/templates/local/post/user.mustache => theme/[themename]/templates/mod_forum/local/post/user.mustache

    The following are _invalid_ template names and locations:
      theme_themename/layouts/columns2: theme/[themename]/layouts/columns2.mustache

=== 3.7 ===
* The core/form_autocompelte_input template now has a `data-tags` attribute.
* Boost theme renderer overrides have now been migrated to core.
* Renderers that were overridden by Boost are now in Bootstrapbase
* Core templates in Boost have now moved into core
* Templates that were overridden by boost are now located in Bootstrapbase
* Themes bootstrapbase, clean & more have now been removed.

=== 3.6 ===

* A new callback has been added to the theme layout files allowing plugins to inject their content
  into the page. For Boost it was added as a mustache variable "{{{ output.standard_after_main_region_html }}}" in
  templates/columns1.mustache and templates/columns2.mustache. In bootstrapbase it was added as a
  function call "$OUTPUT->standard_after_main_region_html()" in layout/columns1.php, layout/columns2.php.
  and layout/columns3.php. Child themes not inheriting these templates should add the function call
  after the div containing the main content region. Please refer to the messaging drawer UI for an example of
  making use of this new feature.
* The body tag has various browser-specific classes for those cases where some
  browser-sniffing is unavoidable. This used not to recognised Microsoft Edge,
  but now it does (class 'edge'). Also, both Safari and Chrome used to be
  class 'safari', but now there are separate classes 'safari' and 'chrome'.
  The body's class should change to match the browser:
  - Google Chrome (Mac & Window): The body class should change from safari to chrome.
  - Google Chrome (Android) : The body class should change from safari, android to chrome, android.
  - Microsoft Edge: The body class should change from safari to edge.
  - Mobile safari: The class ios should exist, safari class should be removed.
* Remove class .safari styling from activity chooser dialog for theme boost and bootstrapbase.
* The following functions and classes have been finally deprecated and can not be used anymore:
  * css_is_colour()
  * css_is_width()
  * css_sort_by_count()
  * core_course_renderer::add_modchoosertoggle()
  * class css_optimiser

=== 3.4 ===

* There was a mustache template login.mustache in /lib/templates/ rendering the login form
  and a template with the same name in /theme/boost/templates/ rendering the pagelayout "login".
  To prevent misunderstanding when overriding one of these templates in a Boost child theme,
  the first one was renamed to loginform.mustache - see MDL-58970.
* The Boost flat navigation nodes now have several data-attributes which let plugin developers
  access properties from the underlying navigation nodes in the browser - see MDL-59425.
* Navigation between activities via a previous and next link was added to Boost, Clean and Bootstrapbase. This
  is made possible by a new function core_renderer->activity_navigation().
* Theme designers may now place the Reset tour on this page link where required by adding an empty
  container (e.g. <div class="tool_usertours-resettourcontainer"></div>) to their layouts.

=== 3.3 ===

* As boost-based themes no longer use the moodle-core-popuphelp help popups, the javascript
  setup for this module have been moved from core standard_head_html to the bootstrapbase
  renderer. If your theme needs this javascript you will need to ensure the bootstrap renderer
  is called, or require the JS yourself

=== 3.2 ===

* Removed themes: base, canvas
  During the upgrade process the themes will be uninstalled and all their settings will be deleted.
  If you wish to keep your theme and its settings, download it from moodle.org and put it back in
  the theme/ directory BEFORE UPGRADING.
* Bootstrap 4 was added as part of a the new theme 'boost'.
* Some backwards and forwards compatibility has been added for different bootstrap versions.
  This is to allow the same markup to work in "clean" and "boost" themes a lot of the time.
  It is also to allow user text with bootstrap classes to keep working in the new theme.
* Using .dir-rtl for RTL styling is deprecated and should not be used any more. From now
  the styles are automatically flipped when the language is right-to-left. However,
  as this is not always perfect, you can define exceptions. Please refer to the documentation
  of the tool RTLCSS-PHP for more information: https://github.com/moodlehq/rtlcss-php
* Themes can now automatically compile SCSS on the fly. This works the same way as it
  does compiling LESS on the fly, effecitvely adding $THEME->scss to your config. The
  latter can either be the name a SCSS file (without extension) in your theme's scss/ folder,
  or a Closure which will return the main SCSS content.
* Two new callbacks allow themes to inject SCSS code before and after the content provided
  by the SCSS file $THEME->scss. See $THEME->prescsscallback and $THEME->extrascsscallback.
* A new callback can be defined to post process the CSS using an object representation
  of the CSS tree ($THEME->csstreepostprocess). This gives a lot more flexibility than a
  simple find and replace. Refer to 'boost' for an example, and to PHP-CSS-Parser.
  (https://github.com/sabberworm/PHP-CSS-Parser) for the API.
* A new core setting now enables admins to upload the logos of their site. Using the
  following methods, themers can instantly support branding logos without the need
  to implement specific theme settings:
  * $OUTPUT->get_logo_url($maxwidth, $maxheight);
  * $OUTPUT->get_compact_logo_url($maxwidth, $maxheight);
* The class .dir-ltr should not be used any more. To force LTR styles use the directive
  to remove the rule when the language is RTL. See RTLCSS-PHP for more information.
* A new class .text-ltr may be used to force the direction to LTR. This is especially useful
  for forms fields (numbers, emails, URLs must not be RTL'd), and for displaying code
  snippets or configuration samples.
* A new theme config 'requiredblocks' allows a theme to define which blocks are deletable.
* You may no longer override the following core_course_renderer methods.
  See course/upgrade.txt for more information:
  - course_modchooser_module_types
  - course_modchooser_module
  - course_modchooser_title
* The question chooser now uses a renderable and a template, the following methods
  have been deprecated in favour of core_question_bank_renderer::render_qbank_chooser().
  - qbank_chooser
  - qbank_chooser_types
  - qbank_chooser_qtype
  - qbank_chooser_title
* The 'css optimiser' has been removed. Developers are encouraged to use tools such as stylelint
  to help optimise their css. Some functions and classes in lib/csslib.php (which was not for public use)
  have been deprecated:
  - css_is_colour
  - css_is_width
  - css_sort_by_count
  - class css_optimiser no longer does anything.
* CLI svgtool.php has moved from theme/base/cli to admin/cli and paths should be relative to the new location.
* mod_chat will now display the 'course theme' option for all themes (previously it was only displayed on
  bootstrap2 based themes).
* Theme can choose how to display "Add a block" control in $THEME->addblockposition, default value is
  BLOCK_ADDBLOCK_POSITION_DEFAULT that displays it as a fake block in editing mode.

=== 3.1 ===

* A new search box for global search has been added to bootstrap and clean layout files, if
  your theme is overwriting columns1.php, columns2.php or columns3.php you will need to add a
  call to core_renderer::search_box to display it.
* Notification templates have been renamed to better suit types of alert
  rather than uses. The following changes have been made:
  * notification_problem.mustache => notification_error.mustache
  * notification_message          => notification_info
  * notification_redirect         => notification_warning
* Method core_course_renderer::course_section_cm_name() is split into two methods, custom themes that override
  this method must be modified or otherwise editing functionality may become broken. This method is now also used by
  social activities block and site menu block to display activities names.

=== 3.0 ===

* The renderer function core_availability_renderer::multiple_messages was changed to
  render_core_availability_multiple_messages, requiring a parameter of the new
  \core_availability\multiple_messages type.
* Meta description is now included in standard_head_html for homepage in bootstrapbase.
  If your theme includes a meta description directly in a layout for the frontpage,
  you will need to remove it or override the standard_head_html instead.
* Themes Clean and More have been updated to use a new navbar_button function, which shows the
  hamburguer icon (responsive menu) or not depending on custom and language menus settings;
  themes extending bootstrapbase and overriding its layouts can call replace their "a.btn-navbar"
  node for a call to this function.
* Themes Clean and More page header logo only displays on front page and login page.
* A new function navbar_home has been added to theme_clean and theme_more to display the navigation bar link
  to the site home. Two new settings have been added to control if the link should be a small logo image, text
  or both. It defaults to the current behaviour, only a text link.

=== 2.9 ===

* Themes Bootstrapbase, Clean and More have undergone some changes for RTL layouts see - MDL-48160.

* Themes Clean amd More page header background logo, if loaded, no longer links to the home page.
* Themes Clean and More have been updated to use the renderer full_header(). This renderer (when in a user context) displays a message button
  and consequently the link to message users have been removed from various pages. It is recommended that theme developers use this
  renderer to ensure that they do not suffer from a reduction in access to this feature.
* $OUTPUT->context_header() has been introduced to produce headers similar to what full_header() creates. This renderer is used for creating
  subsequent headers in a page. If provided with user information, this render will also display a message button like full_header().

=== 2.8 ===

* Themes Base and Canvas layout/embedded.php has changed.
  The div id="content" has been changed to id="page-content" - see MDL-47915.
* All mod_assign CSS selectors have been qualified with ".path-mod-assign". This means any custom CSS
  rules for mod_assign in a theme may need to be updated.
* The following render methods were renamed, if you have overridden any of these you will need to update your renderer:
  - report_log_renderer::render_report_log_renderable         => report_log_renderer::render_report_log
  - report_loglive_renderer::render_report_loglive_renderable => report_loglive_renderer::render_report_log
* On calendar view screen the course selector and new event button have been swapped, custom CSS for .path-calendar might be affected.
* The functions search_listing() and search_pagination() in the core_course_management_renderer class take the searched string
  as an extra parameter - see MDL-46902.
* Themes with non-fixed headers must have the .navbar class in their navbar in order for floating headers in the grader report to work - see MDL-46658.
* To accomodate the new gradebook, use of overflow: hidden or overflow-x: hidden CSS rules on DOM elements containing the
  #user-grades table, visible at [Course administration -> Grades] is not recommended. Please use overflow: auto or
  overflow: scroll instead, as this will handle medium to large courses with multiple activities better (more information available at https://docs.moodle.org/dev/Theme_upgrade_notes ).
* The new user menu can be added to themes by calling $OUTPUT->user_menu(); we recommend doing so in a backwards-compatible way (see https://docs.moodle.org/dev/Theme_upgrade_notes for more information).

=== 2.7 ===

* CSS related functions in theme class and csslib.php were refactored, addons that are
  using this private API need to be updated
* Please update your css to use 'tr:nth-of-type(odd/even)' instead of '.r0/.r1' to apply tr specific css for various tables.
  These classes are deprecated now and will be removed in Moodle 2.9. This has done to better support styling tables that will be altered by JavaScript.
  Here is an example to update your css:
  Old code:
    table.generaltable .r0 {background-color: #F0F0F0;}
    table.generaltable .r1 {background-color: #F0F0F0;}
  New code:
    table.generaltable > tbody > tr:nth-of-type(even) {background-color: #F0F0F0;}
    table.generaltable > tbody > tr:nth-of-type(odd) {background-color: #F0F0F0;}

Removed themes:
* afterburner, anomaly, arialist, binarius, boxxie, brick, formal_white, formfactor, fusion, leatherbound,
  magazine, nimble, nonzero, overlay, serenity, sky_high, splash, standard and standardold have been removed.
  During the upgrade process the themes will be uninstalled and all their settings will be deleted.
  If you wish to keep your theme and its settings, download it from moodle.org and put it back in
  the theme/ directory BEFORE UPGRADING.

Notes:
* z-index on #dock has been adjusted from 11000 to 5000 to prevent overlapping issues with fullscreen TinyMCE in Base theme.

=== 2.6 ===

Removed themes:
* "My Mobile" theme has been removed (see MDL-40874).
  During the upgrade process "My Mobile" theme will be uninstalled and all its settings will be deleted.
  "My Mobile" theme and its extending themes will fallback to the mobile friendly "Clean" theme.
  If you wish to keep "My Mobile" theme and its settings, BEFORE UPGRADING you can copy the files from the
  unmaintained plugin into theme/mymobile.
  The unmaintained plugin can be downloaded at https://moodle.org/plugins/pluginversion.php?id=4563
Notes:
* There have been several changes made to the classes used on headings throughout Moodle.
  This was done as per the Moodle HTML guidelines. h1 and h2 elements should have no classes, h3 and lower headings
  may have descriptive classes only (any classes must properly describe the relation between the header and its content).
* The parameters value for the following functions have been modified: core_renderer::heading() and core_renderer::heading_with_help().
  This means that headings using the default options will no longer have the class "main" which was the previous default.
* The file picker and activity chooser have been converted to use M.core.dialogue. This means the styles
  for these elements have changed in the base and bootstrapbase themes and you will need to copy the new styles
  if you are not inheriting from either one of these themes.
* For the themes based on bootstrapbase please also read theme/bootstrapbase/upgrade.txt
* A new component action_menu is now used to display editing icons for courses and blocks within a drop down. If you have a theme that doesn't
  extend base, canvas, or clean then you will need to style for this new component within your theme.
* The maintenance layout now has a special renderer that extends the core_renderer in order to prevent some methods from interacting
  with the database. Please be aware that for the maintenance layout some methods now always return an empty string.
  This has been done because it is important that during maintenance routines we don't show any links, interact with the database,
  or interact with caches as doing so may lead to errors,
  Please see the maintenance renderer notes below for details on the functions affected.

Renderer changes:
* core_course_renderer::course_section_cm_edit_actions has two new optional arguments and now uses and action_menu component.
* core_course_renderer::course_section_cm has been altered to call core_course_renderer::course_section_cm_edit_actions with the two new arguments.
* core_renderer::block_controls has a new optional argument (the block id) and has been altered to use the new action_menu component.
* core_renderer::block_header has been altered to give core_renderer::block_controls the new second argument, the block id.
* core_renderer::action_link has a new argument, and optional icon that can be rendererd into the link.

Selector changes:
* Changes to the classes given to the header produced when rendering a single section within a course.
  .section-navigation.header.headingblock => .section-navigation.navigationtitle
* Changes to the classes used when producing the course information box that lists courses.
  The name (h3|div} of both courses and categories used to have .name, for courses in the list this was changed to .coursename and for categories in the list this was changed to .categoryname.
* Classes ".header and .headingblock" were removed from all front page content headings.
* Classes ".headingblock .header .tag-header" were removed from the tag index page

Maintenance renderer notes:
When the maintenance layout is being used $OUTPUT will be an instance of core_renderer_maintenance.
This renderer mimics the core_renderer except that the following functions always return an empty string.
* core_renderer_maintenance::block
* core_renderer_maintenance::blocks
* core_renderer_maintenance::blocks_for_regions
* core_renderer_maintenance::course_header
* core_renderer_maintenance::course_footer
* core_renderer_maintenance::course_content_header
* core_renderer_maintenance::course_content_footer
* core_renderer_maintenance::custom_menu
* core_renderer_maintenance::file_picker
* core_renderer_maintenance::htmllize_file_tree
* core_renderer_maintenance::lang_menu
* core_renderer_maintenance::login_info
* core_renderer_maintenance::user_picture

If you have overridden methods of the core_renderer in your theme and want those changes to be shown during times of maintenance you
will also need to override the core_renderer_maintenance and copy your customisations from the core_renderer to that.

=== 2.5.1 ===

Notes:
* Block drag and drop functionality has been improved so that it works regardless of what block regions you use
  or how many block regions you have. In order to benefit from this improvement you must convert your calls from
  $OUTPUT->blocks_for_region() to $OUTPUT->blocks.

Optional changes:
* Theme config can nominate block regions to swap if the user is using a rtl languages such as Hebrew.
  $THEME->blockrtlmanipulations should be an associative array, the key is the original block region, and the
  value should be where the blocks in that region should be displayed.
* New $OUTPUT methods to replace code that was previously using $PAGE. Converting to these methods is optional
  but highly recommended. Refer to the bootstrapbase layouts for examples.
  - $OUTPUT->body_attributes() returns a string you can use for the body id and classes.
  - $OUTPUT->blocks() returns HTML to display a block region and all of its blocks. This adds data attributes
    that ensure drag and drop of blocks will work no matter what block regions or how many you have.
  - $OUTPUT->page_heading() returns the page heading. Replaces $PAGE->heading.
  - $OUTPUT->page_heading_button() returns the button to display with the heading. Replaces $page->button.
  - $OUTPUT->page_doc_link() returns the link to moodle docs for the page. Replaces page_doc_link().
  - $OUTPUT->page_heading_menu() returns the heading menu for the page. Replaces $PAGE->headingmenu.
  - $OUTPUT->page_title() Returns the title to use for the head section.
  - $OUTPUT->favicon() returns the URL to the favicon.

Renderer changes:
* core_renderer::navbar now returns an empty string if there are no navigation items to display.
* core_renderer::custom_menu now adds a class "custom_menu" to the div that contains the HTML for the custom menu.

=== 2.5 ===

required changes:
* Functions core_course_renderer::course_category_tree() and course_category_tree_category()
  are deprecated
* Significant changes in rendering of courses and categories listings, lots of CSS classes changed,
  several functions such as print_courses(), print_whole_category_list(), print_category_info()
  are moved to course renderer.
  See http://docs.moodle.org/dev/Courses_lists_upgrade_to_2.5

DOM changes:
* changed the h1 title in the help popup to a h2.
* new setting $THEME->yuicssmodules = array('cssreset', 'cssfonts', 'cssgrids', 'cssbase'); which
  allows themes to use different CSS reset normalisers such as cssnormalize YUI module.
* Re-wrote the user profile views to definition lists.
* Re-wrote the table for the course completion status block to use html_table - added some CSS classes to
  the table in the process (see MDL-35608).
* Cancel buttons have the class btn-cancel.
* Added a z-index for the div#dateselector-calendar-panel so that the calendar pop-up renders above
  the filemanager when they overlap, ie. the course settings page (see MDL-39047).
* Trivial change of CSS selectors used to display plugin status at the plugins overview
  screen (#plugins-control-panel).

Renderer changes:
* Mymobile theme changed to support more verbose move-block-here descriptions.

=== 2.4 ===

required changes:
* output course and course content header/footer that may be returned by course format (see MDL-36048)
* span.completionprogress has been changed to a <div> and is not a float by default any more.

deprecation:
* i/roles: Use t/assignroles instead
* t/manual_item: Use i/manual_item instead
* t/unlock_gray: Use t/locked instead
* t/userblue: Previously used to unblock a user, use t/unblock.
* c/course: Use i/courseevent instead
* c/group: Use i/groupevent instead
* c/site: Use i/siteevent instead
* c/user: Use i/userevent instead
* t/clear: Use t/check instead
* i/cross_red_big: Use i/invalid or i/grade_incorrect
* i/tick_green_big: Use i/valid or i/grade_correct
* i/tick_amber_big: Use i/caution or i/grade_partiallycorrect
* No more small versions of i/cross_red_small, i/tick_green_small and i/tick_amber_small, use their big equivalent.
* t/addgreen: Use t/add instead.
* i/approve: Use t/approve instead

optional changes:
* new optional boolean parameter $withlinks for public function login_info() in lib/outputrenderers.php (MDL-31365)
* new layout option "nologinlinks" and new page layout "secure" e.g. for safebrowser and securewindow (MDL-31365)
* new class 'iconlarge' for 24x24 icons.
* new icons i/export and i/import (sized 16x16). Previously export and import actions used i/backup and i/restore.
* new icon i/assignroles (sized 16x16), to prevent the use of i/roles which is 12x12.
* new icon i/switchrole (sized 16x16), was previously using i/roles. Now is a copy of the new i/assignroles icon.
* new icons i/enrolusers and t/enrolusers, previsouly i/users was used.
* new icon t/cohorts (sized 12x12), to prevent the use of i/cohorts which is 16x16.
* new icons t/sort_asc, t/sort_desc to use for ordering in table headers.
* new class 'iconsort' for icons used for ordering in table headers.
* new icons t/locked and t/unlocked (12x12) which should be used when there is no action associated to the icon.
* new icons i/folder (16x16), monochrome equivalent to f/folder.
* new icons t/addcontact, t/removecontact and t/messages, previously t/addgreen, t/delete and t/log were used in messaging.
* new icons t/unblock and i/twoway.
* new icons i/courseevent, i/groupevent, i/siteevent and i/userevent (16x16) instead of c/* for calendar events.
* new icon t/markasread (12x12) to replace t/clear used in forums.
* new icon t/check (12x12) to replace t/clear which name does not reflect the icon meaning.
* new classes 'icon-pre' and 'icon-post' supposedly to be used when the icon is positioned before or after the text. This is not really used yet, but it's a start towards some standardisation of the icon selectors.
* new icons i/valid, i/caution and i/invalid for generic statuses.
* new icons i/grade_correct, i/grade_partiallycorrect and i/grade_incorrect for grades.
* new icon t/approve (12x12).
* new icon t/contextmenu (12x12) for a monochrome version of i/menu.

=== 2.3 ===

optional changes:
* add new u/f3.png image when theme contains customised f1 and f2 default user images

=== 2.2 ===

required changes:
* use new page content placeholder "echo $OUTPUT->main_content()" instead of "echo core_renderer::MAIN_CONTENT_TOKEN"
  see git commit: 3b3f302855d7621405a8b93e49bd399d67a998d7
* upgrade report selectors: search for "-course-report-" and replace with "-report-"
