Notes about legacy page classes

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The page is some notes about the legacy lib/pagelib.php, and is solely for my benefit as I plan how to change it in Navigation 2.0 implementation plan without breaking backwards compatibility too badly ;-)

Definition of page classes

page_base subclasses that exist in core

List of the classes according to the file which defines them.

lib/pagelib.php: page_base, __construct, construct, init_full, init_quick, get_type, get_id, get_format_name, get_body_class, get_body_id, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, blocks_get_default, url_get_path, url_get_parameters, url_get_full, user_allowed_editing, user_is_editing, edit_always; page_course extends page_base, init_full, init_quick, get_type, get_format_name, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, blocks_get_default, url_get_path, url_get_parameters, user_allowed_editing, user_is_editing; page_generic_activity extends page_base, init_full, print_header, blocks_get_positions, blocks_default_position, url_get_parameters, url_get_path, user_allowed_editing, user_is_editing

✔ admin/pagelib.php: page_admin extends page_base, get_type, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, blocks_get_default, url_get_path, url_get_parameters, user_allowed_editing, user_is_editing, init_extra, set_extra_button, set_extra_url_params

blog/blogpage.php why isn't this called pagelib.php?: page_blog extends page_base, init_full, init_quick, get_type, get_format_name, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, blocks_get_default, url_get_path, url_get_parameters, user_allowed_editing, user_is_editing, get_extra_header_string

mod/chat/pagelib.php: page_chat extends page_generic_activity, init_quick, get_type

mod/data/pagelib.php: page_data extends page_generic_activity, init_quick, get_type, print_header

mod/lesson/pagelib.php: page_lesson extends page_generic_activity, get_type, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, url_get_parameters, set_lessonpageid

mod/quiz/pagelib.php: page_quiz extends page_generic_activity, init_quick, get_type

my/pagelib.php: page_my_moodle extends page_base, get_type, print_header, blocks_get_positions, blocks_default_position, blocks_move_position, url_get_parameters, url_get_path, user_allowed_editing, user_is_editing

✔ tag/pagelib.php: page_tag extends page_base, get_type, get_format_name, print_header, print_footer, blocks_get_positions, blocks_default_position, blocks_move_position, url_get_parameters, url_get_path, user_allowed_editing, user_is_editing

Pagelib files in contrib

I checked the HEAD and 1.9 branches in contrib CVS.

patches/center_blocks_position_patch/lib/pagelib.php: This is a hack that becomes obsolete. No worries.

plugins/mod/dimdim/pagelib.php: page_dimdim extends page_generic_activity, init_quick, get_type, print_header

plugins/mod/game/pagelib.php: page_game extends page_generic_activity, init_quick, get_type, print_header

plugins/mod/oublog/pagelib.php: page_game extends page_generic_activity, init_quick, get_type

plugins/mod/wiki/pagelib.php: page_wiki extends page_generic_activity, init_quick, get_type, print_header, blocks_move_position

Uses of $PAGE

In core

190 references to $PAGE in 30 files

Pages that need a small amount of standard re-work (which should be documented on Migrating your code code to the 2.0 rendering API as I do it). That is, only uses the things listed as 'Calls to' in the next section.

course/format/scorm/format.php
course/format/social/format.php
course/format/topics/format.php
course/format/weeks/format.php
course/rest.php
course/view.php
lib/moodlelib.php - isediting function, which we may deprecate since we can now use $PAGE->is_editing() everywhere
lib/weblib.php - three todos that are waiting for $PAGE->context
mod/chat/view.php
mod/data/view.php
mod/lesson/action/continue.html
mod/lesson/action/continue.php
mod/lesson/locallib.php
mod/lesson/view.php - special $PAGE->set_lessonpageid bit. Replace with $PAGE->set_sub_page.
mod/lesson/viewend.php
mod/lesson/viewstart.php
mod/quiz/view.php
mod/resource/lib.php
my/index.php
tag/index.php
index.php

Pages that need a bit more work that that:

Things relating to page-admin and $PAGE->section
- admin/settings.php
- blocks/admin_bookmarks/block_admin_bookmarks.php
- blocks/admin_tree/block_admin_tree.php
- lib/adminlib.php
blocks/moodleblock.class.php - checks $PAGE->type and ->id

Pages that will need major rework

lib/blocklib.php
admin/stickyblocks.php - will be replaced by the new block editing UI.
blog
- blog/footer.php
- blog/header.php - sets lots of stuff like $PAGE->courseid, $PAGE->filterselect, $PAGE->tagid - looks like abuse of global variables.

In contrib

204 references, but 122 if you exclude contrib/old on the 1.9 branch. 163 references if you exclude contrib/old on the HEAD branch.

Calls to

$PAGE = page_create_object(...)
$pageblocks = blocks_setup($PAGE, ...)
blocks_print_group($PAGE, ...)
$pageblocks = blocks_get_by_page($PAGE)
$PAGE->user_allowed_editing()
$PAGE->user_is_editing()
$missingblocks = blocks_get_missing($PAGE, $pageblocks) Missing blocks are really means blocks that the user is allowed to add to this page.
$PAGE->print_header($title)
$PAGE->url_get_full(...)
unset($PAGE->_user_allowed_editing) horribly, I have seen this hack in several places! will not be backwards compatible, but there will be a new method to do this.

We should be able to support all that in a backwards compatible way.

More complex stuff in

patches/blocktopbottom/... - but that will be obsolete.
patches/center_blocks_position_patch/... - but that will be obsolete.
patches/dragmath seems to ship a custom lib/adminlib.php - no idea why, but I am not going to worry about breaking it.
plugins/mod/customlabel/_goodies/course/format/page/actions/activities.php refers to a non-existent $PAGE->print_tabs(...).
plugins/theme/wood_custom_corners/header.html does some nasty hacking based on page type. Will break.

I expect most of that will break, but I don't think there is anything that important in that list.

What happens to the various pagelib methods

init_full
init_quick: need to work out if any of this logic is important, and if so move it

✔ blocks_get_positions
✔ blocks_default_position
✔ blocks_move_position: obsoleted by the new blocks system. We will just make deprecated functions that do nothing just to prevent fatal errors.

✔ blocks_get_default: actually, we don't need a general default blocks mechanism. Instead we should be using sticky blocks for most things. The one exception is default blocks on the course page. We will implement that as a special case using the existing $CFG variables.

✔ user_allowed_editing: the logic from subclass implementations needs to be moved elsewhere

✔ user_is_editing: keep

✔ get_type: becomes return $PAGE->pagetype

✔ get_format_name: this is used to filter the allowed blocks by course format, something only about 2 blocks actually take advantage of. I think the correct solution is to set $PAGE->pagetype to, e.g. course-view-weeks or course-edit-weeks on the course view/edit page, and make get_format_name a deprecated synonym for get_type.

get_id: only used by blocklib when working out what blocks appear on a page, so remove after upgrading the blocks database tables

print_header: need to examine the logic in all subclasses, and work out what to do about it

✔ edit_always: only used by admin/stickyblocks.php - though the reference is actually in lib/blockslib.php - remove

✔ url_get_path
✔ url_get_full: keep deprecated implementations in terms of $PAGE->url

✔ url_get_parameters: move logic from subclasses that used to be here elsewhere, then reimplement in terms of $PAGE->url

✔ get_body_class
✔ get_body_id: not used anywhere, remove

✔ init_extra
set_extra_button
✔ set_extra_url_params: hacks I added to the admin page class - fix admin and remove

✔ get_extra_header_string: only used by blog - remove

set_lessonpageid: only used by lesson - remove and use with $PAGE->subpage instead

✔ print_footer: only defined/used in tags - remove.

✔ $CFG->pagepath: This was an evil hack - remove - replace with $PAGE->set_pagetype()

ADMIN_STICKYBLOCKS: this constant is defined by admin/stickyblocks.php as a hack to let the blocks code know we are editing stickyblocks. Remove this once the new blocks editing is done.

Documentation