6d77cdfd65
This PR was squashed before being merged into the 3.3-dev branch (closes #21478).
Discussion
----------
[Asset] Add support for preloading with links and HTTP/2 push
| Q | A
| ------------- | ---
| Branch? | master
| Bug fix? | no
| New feature? | yes
| BC breaks? | no
| Deprecations? | no
| Tests pass? | yes
| Fixed tickets | n/a
| License | MIT
| Doc PR | todo
Allows compatible clients to preload mandatory assets like scripts, stylesheets or images according to [the "preload" working draft of the W3C](https://www.w3.org/TR/preload/).
Thanks to this PR, Symfony will automatically adds `Link` HTTP headers with a `preload` relation for mandatory assets. If an intermediate proxy supports HTTP/2 push, it will convert preload headers. For instance [Cloudflare supports this feature](https://blog.cloudflare.com/using-http-2-server-push-with-php/).
It dramatically increases pages speed and make the web greener because only one TCP connection is used to fetch all mandatory assets (decrease servers and devices loads, improve battery lives).
Usage:
Updated version:
```html
<html>
<body>
Hello
<script src="{{ preload(asset('/scripts/foo.js'), 'script') }}"></script>
</body>
</html>
```
~~First proposal:~~
```html
<html>
<body>
Hello
<script src="{{ preloaded_asset('/scripts/foo.js', 'script') }}"></script>
</body>
</html>
```
- [x] Add tests
Commits
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|---|---|---|
| .composer | ||
| .github | ||
| src/Symfony | ||
| .editorconfig | ||
| .gitignore | ||
| .php_cs.dist | ||
| .travis.yml | ||
| appveyor.yml | ||
| CHANGELOG-3.0.md | ||
| CHANGELOG-3.1.md | ||
| CHANGELOG-3.2.md | ||
| composer.json | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS.md | ||
| LICENSE | ||
| phpunit | ||
| phpunit.xml.dist | ||
| README.md | ||
| UPGRADE-3.0.md | ||
| UPGRADE-3.1.md | ||
| UPGRADE-3.2.md | ||
| UPGRADE-3.3.md | ||
| UPGRADE-4.0.md | ||
README
What is Symfony?
Symfony is a PHP full-stack web framework. It is written with speed and flexibility in mind. It allows developers to build better and easy to maintain websites with PHP.
Symfony can be used to develop all kind of websites, from your personal blog to high traffic ones like Dailymotion or Yahoo! Answers.
Installation
The best way to install Symfony is to use the official Symfony Installer. It allows you to start a new project based on the version you want.
Documentation
The "Quick Tour" tutorial gives you a first feeling of the framework. If, like us, you think that Symfony can help speed up your development and take the quality of your work to the next level, read the official Symfony documentation.
Contributing
Symfony is an open source, community-driven project. If you'd like to contribute, please read the Contributing Code part of the documentation. If you're submitting a pull request, please follow the guidelines in the Submitting a Patch section and use Pull Request Template.
Community Reviews
If you don't feel ready to contribute code or patches, reviewing issues and pull
requests can be a great start to get involved and give back. In fact, people who
"triage" issues are the backbone to Symfony's success!
More information can be found in the Community Reviews guide.
Running Symfony Tests
Information on how to run the Symfony test suite can be found in the Running Symfony Tests section.