mirror of
https://gerrit.wikimedia.org/r/mediawiki/extensions/Popups
synced 2024-12-23 20:43:15 +00:00
7ef925fb97
It is probably not that critical to understand if "09/11/2016" refers to September 11th or November 9th. I still think it's worth looking for a documentation format that is easy to understand by an international developers community. My personal best practice is to use the ISO format. Change-Id: Ib209a8a1651970d74f82c188ae4b84d1a4eb534e
89 lines
4.7 KiB
Markdown
89 lines
4.7 KiB
Markdown
# 10. Replace Mustache.js with Template Literals
|
|
|
|
Date: 2018-03-22
|
|
|
|
## Status
|
|
|
|
Accepted
|
|
|
|
## Context
|
|
|
|
UI HTML templates are currently populated with variables by the [mustache.js]
|
|
template system. This is consistent with other code in MediaWiki but adds an
|
|
8.1 KiB dependency* for functionality that is only used in a few places.
|
|
|
|
Given that ES6 template literals provide similar readability and are part of
|
|
JavaScript itself, we considered this to be a favorable and sustainable
|
|
alternative to Mustache templates. Additionally, although the usage of template
|
|
strings requires transpilation, adding transpiling support enables other ES6
|
|
syntaxes to be used such as let / const, arrow functions, and destructuring, all
|
|
of which are considered language improvements that Extension:Popups can leverage
|
|
in many areas.
|
|
|
|
We used the [Babel transpiler] with [babel-preset-env] to translate only the
|
|
necessary JavaScript from ES6 to ES5 for [grade A browsers]. The overhead for
|
|
this functionality is nonzero but expected to diminish in time and always be
|
|
less than the size of the Mustache.js dependency. Please note that while most
|
|
ES6 syntaxes are supported, the transpiler does not provide polyfills for new
|
|
APIs (e.g., `Array.prototype.includes()`) unless configured to do so via
|
|
[babel-polyfill]. As polyfills add more overhead and are related but independent
|
|
of syntax, API changes were not considered in this refactoring.
|
|
|
|
We also realized that manual HTML escaping of template parameters would be a
|
|
necessary part of this change. This functionality is built into the double-curly
|
|
brace syntax of mustache.js but is now performed using [mw.html.escape()]. These
|
|
calls are a blemish on the code but appear only in the templates themselves and
|
|
would be replaced transparently in a UI library such as Preact which leverages
|
|
JSX. We also anticipate that the template literal syntax would transition neatly
|
|
to JSX. We don't know that Extension:Popups will ever want to use a UI library
|
|
and accept these shortcomings may always exist.
|
|
|
|
*As reported by [mw.loader.inspect()] on 2018-03-22.
|
|
|
|
[mustache.js]: https://github.com/janl/mustache.js
|
|
[Babel transpiler]: https://babeljs.io
|
|
[babel-preset-env]: https://babeljs.io/docs/plugins/preset-env
|
|
[grade A browsers]: https://www.mediawiki.org/wiki/Compatibility#Browsers
|
|
[babel-polyfill]: https://babeljs.io/docs/usage/polyfill
|
|
[mw.html.escape()]: https://www.mediawiki.org/wiki/ResourceLoader/Core_modules#mediaWiki.html
|
|
[mw.loader.inspect()]: https://www.mediawiki.org/wiki/ResourceLoader/Core_modules#mw.loader.inspect
|
|
|
|
## Decision
|
|
|
|
We compared the sizes before (d35286a) and after (4281670) transpiling and they
|
|
proved favorable:
|
|
|
|
| Commit | index.js (gzip) | index.js | ext.popups | ext.popups.main | ext.popups.images | mediawiki.template.mustache | Total |
|
|
| ------ | --------------: | --------: | ---------: | --------------: | ----------------: | --------------------------: | ---------: |
|
|
| Before | 10.84 KiB | 32.88 KiB | 96 B | 52.5 KiB | 3.1 KiB | 8.1 KiB | **65224B** |
|
|
| After | 11.46 KiB | 35.15 KiB | 96 B | 52.7 KiB | 3.1 KiB | 0.0 KiB | **57193B** |
|
|
|
|
Where "index.js (gzip)" is the minified gzipped size of the
|
|
resources/dist/index.js Webpack build product as reported by [bundlesize],
|
|
"index.js" is the minified uncompressed size of the same bundle as reported by
|
|
[source-map-explorer] and [Webpack performance hints], and the remaining columns
|
|
are the sum of minified uncompressed JavaScript and CSS sizes for each relevant
|
|
module as reported by mw.loader.inspect() with the last column being a total of
|
|
these inspect() modules.
|
|
|
|
The conclusions to draw from this table are that transpilation does increase the
|
|
size of the Webpack bundle but that the overhead is less than that of the
|
|
Mustache.js dependency so the overall effect is a size improvement.
|
|
Additionally, note that the transpiled bundle now encompasses the HTML templates
|
|
which source-map-explorer reports as contributing a 2.53 KiB minified
|
|
uncompressed portion of the 35.15 KiB bundle. (Previously, templates were an
|
|
additional request.) Allowing for rounding errors, this brings the approximate
|
|
overhead of enabling transpilation to nearly zero, 35.15 KiB - 32.88 KiB -
|
|
2.53 KiB ≈ 0, which suggests transpiling as a viable solution for improving code
|
|
elsewhere that must be written in modern form without compromising on
|
|
compatibility or performance.
|
|
|
|
[bundlesize]: https://github.com/siddharthkp/bundlesize
|
|
[source-map-explorer]: https://github.com/danvk/source-map-explorer
|
|
[Webpack performance hints]: https://webpack.js.org/configuration/performance
|
|
|
|
## Consequences
|
|
|
|
ES6 syntax is enabled without changing existing device support and 7.8 KiB less
|
|
of minified uncompressed JavaScript is delivered.
|