* The styles queue has always been top-only
(except for a few months in 2015).
* The top queue loads asynchronous since mid-2015. (T107399)
And LocalStorage eval, previously the last remaining non-async part
of module loading, is also async as of October 2016. (T142129)
* This change merges the bottom 'mw.loader.load()' queue with the top queue.
It also moves any other snippets potentially in the bottom queue still:
- embed: I couldn't find any private modules with position=bottom
(doesn't make sense due to their blocking nature). If any do exist,
(third-party extensions?), they'll now be embedded in the <head>.
- scripts: Any legacy 'only=scripts' requests will now initiate
from the <head>.
Bug: T109837
Change-Id: I6c21e3e47c23df33a04c42ce94bd4c1964599c7f
Follows-up 6fa1e56. This is already fixed for http caches by
shortening the Cache-Control max-age in case of a version mismatch.
However the client still cached it blindly in mw.loader.store.
Resolve this by communicating to the client what version of the module
was exported. The client can then compare this version to the version
it originally requested and decide not to cache it.
Adopt the module key format (name@version) from mw.loader.store
in mw.loader.implement() as well.
Bug: T117587
Change-Id: I1a7c44d0222893afefac20bef507bdd1a1a87ecd
HTML formatting of the queue was distributed over several OutputPage methods.
Each method demanding a snippet of HTML by calling makeResourceLoaderLink()
with a limited amount of information. As such, makeResourceLoaderLink() was
unable to provide the client with the proper state information.
Centralising it also allows it to better reduce duplication in HTML output
and maintain a more accurate state.
Problems fixed by centralising:
1. The 'user' module is special (due to per-user 'version' and 'user' params).
It is manually requested via script-src. To avoid a separate (and wrong)
request from something that requires it, we set state=loading directly.
However, because the module is in the bottom, the old HTML formatter could
only put state=loading in the bottom also. This sometimes caused a wrong
request to be fired for modules=user if something in the top queue
triggered a requirement for it.
2. Since a464d1d4 (T87871) we track states of page-style modules, with purpose
of allowing dependencies on style modules without risking duplicate loading
on pages where the styles are loaded already. This didn't work, because the
state information about page-style modules is output near the stylesheet,
which is after the script tag with mw.loader.load(). That runs first, and
mw.loader would still make a duplicate request before it learns the state.
Changes:
* Document reasons for style/script tag order in getHeadHtml (per 09537e83).
* Pass $type from getModuleStyles() to getAllowedModules(). This wasn't needed
before since a duplicate check in makeResourceLoaderLink() verified the
origin a second time.
* Declare explicit position 'top' on 'user.options' and 'user.tokens' module.
Previously, OutputPage hardcoded them in the top. The new formatter doesn't.
* Remove getHeadScripts().
* Remove getInlineHeadScripts().
* Remove getExternalHeadScripts().
* Remove buildCssLinks().
* Remove getScriptsForBottomQueue().
* Change where Skin::setupSkinUserCss() is called. This methods lets the skin
add modules to the queue. Previously it was called from buildCssLinks(),
via headElement(), via prepareQuickTemplate(), via OutputPage::output().
It's now in OutputPage::output() directly (slightly earlier). This is needed
because prepareQuickTemplate() calls bottomScripts() before headElement().
And bottomScript() would lazy-initialise the queue and lock it before
setupSkinUserCss() is called from headElement().
This makes execution order more predictable instead of being dependent on
the arbitrary order of data extraction in prepareQuickTemplate (which varies
from one skin to another).
* Compute isUserModulePreview() and isKnownEmpty() for the 'user' module early
on so. This avoids wrongful loading and fixes problem 1.
Effective changes in output:
* mw.loader.state() is now before mw.loader.load(). This fixes problem 2.
* mw.loader.state() now sets 'user.options' and 'user.tokens' to "loading".
* mw.loader.state() now sets 'user' (as "loading" or "ready"). Fixes problem 1.
* The <script async src> tag for 'startup' changed position (slightly).
Previously it was after all inline scripts and stylesheets. It's still after
all inline scripts and after most stylesheets, but before any user styles.
Since the queue is now formatted outside OutputPage, it can't inject the
meta-ResourceLoaderDynamicStyles tag and user-stylesheet hack in the middle
of existing output. This shouldn't have any noticable impact.
Bug: T87871
Change-Id: I605b8cd1e1fc009b4662a0edbc54d09dd65ee1df
