Assets injection library is missing assets management component that combines Dependency Injection and Assetic in one library that helps full stack developers/front end developers to include necessary javascripts and stylesheets into template without worrying about dependencies and order of inclusion.
If projects such as Bower or Components (or some other similar project) will help you to pull assets from Github to your project directory, this component will help you to include those assets into template.
In this example, we will presume that you use Twig. So in your template:
<html>
<head>
<!-- ... your code ... -->
{% css %}
<!-- ... your code ... -->
</head>
<body>
<!-- ... your code ... -->
{% inject 'my-asset-library' %}
<!-- ... your code ... -->
{% js %}
</body>
</html>
And let's say that it is defined that your library my-asset-library depends on jquery-ui and jquery-ui needs jquery,
that would mean that you have to add that code to HEAD/BODY tag in correct order.
This library solves that issue, resolving all those dependencies, loading and injecting all required javascripts and stylesheets based on definitions of libraries. So, your result might look like:
<html>
<head>
<!-- ... your code ... -->
<link rel="stylesheet" type="text/css" href="lib/jquery-ui/jquery-ui.min.css" />
<link rel="stylesheet" type="text/css" href="app/my-app.css" />
<!-- ... your code ... -->
</head>
<body>
<!-- ... your code ... -->
<!-- ... your code ... -->
<script type="text/javascript" href="lib/jquery/jquery.min.css"></script>
<script type="text/javascript" href="lib/jquery-ui/jquery-ui.min.css"></script>
<script type="text/javascript" href="app/my-app.js"></script>
</body>
</html>
One single {% inject "library-name" %} will save you from all that hassle...!
And that is not all - you can configure library to combine and compress all those assets into one file, so your result might look like this in production enviroment:
<html>
<head>
<!-- ... your code ... -->
<link rel="stylesheet" type="text/css" href="cache/app.css" />
<!-- ... your code ... -->
</head>
<body>
<!-- ... your code ... -->
<!-- ... your code ... -->
<script type="text/javascript" href="cache/app.js"></script>
</body>
</html>
Can you see that LINK tag in HEAD is rendered properly, even thoug assets are injected AFTER rendering logic? We didn't
use str_replace, nor some nasty hacks - we made Twig to buffer its output and delay execution of portions of templates
in order to achieve this result.
And this was not easy task, see: Sonata base layout,
note {{ sonata_block_include_stylesheets('screen', app.request.basePath) }} at the bottom - stylesheets are not loaded
where they should be - in HEAD tag.
We figure out how to overcome above mentioned issue, and this library was developed having in mind Sonata and Drupal dynamic-block-like content.
Note that this library is still under heavy development, and first release is expected in October, 2015, as well as Symfony bundle.