2014-10-13 09:49:30 +02:00
|
|
|
title: Requirements
|
|
|
|
summary: How to include and require other assets in your templates such as javascript and CSS files.
|
|
|
|
|
|
|
|
# Requirements
|
|
|
|
|
|
|
|
The requirements class takes care of including CSS and JavaScript into your applications. This is preferred to hard
|
|
|
|
coding any references in the `<head>` tag of your template, as it enables a more flexible handling through the
|
|
|
|
[api:Requirements] class.
|
|
|
|
|
|
|
|
## Template Requirements API
|
|
|
|
|
|
|
|
**mysite/templates/Page.ss**
|
|
|
|
|
|
|
|
:::ss
|
|
|
|
<% require css("cms/css/TreeSelector.css") %>
|
|
|
|
<% require themedCSS("TreeSelector") %>
|
|
|
|
<% require javascript("cms/javascript/LeftAndMain.js") %>
|
|
|
|
|
|
|
|
<div class="alert" markdown="1">
|
|
|
|
Requiring assets from the template is restricted compared to the PHP API.
|
|
|
|
</div>
|
|
|
|
|
|
|
|
## PHP Requirements API
|
|
|
|
|
|
|
|
It is common practice to include most Requirements either in the *init()*-method of your [controller](../controller), or
|
|
|
|
as close to rendering as possible (e.g. in `[api:FormField]`.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
<?php
|
|
|
|
|
|
|
|
class MyCustomController extends Controller {
|
|
|
|
|
|
|
|
public function init() {
|
|
|
|
parent::init();
|
|
|
|
|
|
|
|
Requirements::javascript("cms/javascript/LeftAndMain.js");
|
|
|
|
Requirements::css("cms/css/TreeSelector.css");
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
### CSS Files
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::css($path, $media);
|
|
|
|
|
|
|
|
If you're using the CSS method a second argument can be used. This argument defines the 'media' attribute of the
|
|
|
|
`<link>` element, so you can define 'screen' or 'print' for example.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::css("cms/css/TreeSelector.css", "screen,projection");
|
|
|
|
|
|
|
|
### Javascript Files
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::javascript($path);
|
|
|
|
|
|
|
|
A variant on the inclusion of custom javascript is the inclusion of *templated* javascript. Here, you keep your
|
|
|
|
JavaScript in a separate file and instead load, via search and replace, several PHP-generated variables into that code.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
$vars = array(
|
|
|
|
"EditorCSS" => "cms/css/editor.css",
|
|
|
|
);
|
|
|
|
|
|
|
|
Requirements::javascriptTemplate("cms/javascript/editor.template.js", $vars);
|
|
|
|
|
2014-10-30 05:16:38 +01:00
|
|
|
In this example, `editor.template.js` is expected to contain a replaceable variable expressed as `$EditorCSS`.
|
|
|
|
|
2014-10-13 09:49:30 +02:00
|
|
|
### Custom Inline CSS or Javascript
|
|
|
|
|
|
|
|
You can also quote custom script directly. This may seem a bit ugly, but is useful when you need to transfer some kind
|
|
|
|
of 'configuration' from the database in a raw format. You'll need to use the `heredoc` syntax to quote JS and CSS,
|
|
|
|
this is generally speaking the best way to do these things - it clearly marks the copy as belonging to a different
|
|
|
|
language.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::customScript(<<<JS
|
|
|
|
alert("hi there");
|
|
|
|
JS
|
|
|
|
);
|
|
|
|
|
|
|
|
Requirements::customCSS(<<<CSS
|
|
|
|
.tree li.$className {
|
|
|
|
background-image: url($icon);
|
|
|
|
}
|
|
|
|
CSS
|
|
|
|
);
|
|
|
|
|
|
|
|
## Combining Files
|
|
|
|
|
|
|
|
You can concatenate several CSS or javascript files into a single dynamically generated file. This increases performance
|
|
|
|
by reducing HTTP requests.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::combine_files(
|
|
|
|
'foobar.js',
|
|
|
|
array(
|
|
|
|
'mysite/javascript/foo.js',
|
|
|
|
'mysite/javascript/bar.js',
|
|
|
|
)
|
|
|
|
);
|
|
|
|
|
|
|
|
<div class="alert" markdown='1'>
|
|
|
|
To make debugging easier in your local environment, combined files is disabled when running your application in `dev`
|
|
|
|
mode.
|
|
|
|
</div>
|
|
|
|
|
2014-10-30 05:16:38 +01:00
|
|
|
By default it stores the generated file in the assets/ folder, but you can configure this by pointing the
|
2014-10-13 09:49:30 +02:00
|
|
|
`Requirements.combined_files_folder` configuration setting to a specific folder.
|
|
|
|
|
|
|
|
**mysite/_config/app.yml**
|
|
|
|
|
|
|
|
:::yml
|
|
|
|
Requirements:
|
|
|
|
combined_files_folder: '_combined'
|
|
|
|
|
|
|
|
<div class="info" markdown='1'>
|
|
|
|
If SilverStripe doesn't have permissions on your server to write these files it will default back to including them
|
|
|
|
individually. SilverStripe **will not** rewrite your paths within the file.
|
|
|
|
</div>
|
|
|
|
|
|
|
|
You can also combine CSS files into a media-specific stylesheets as you would with the `Requirements::css` call - use
|
|
|
|
the third paramter of the `combine_files` function:
|
|
|
|
|
|
|
|
:::php
|
|
|
|
$printStylesheets = array(
|
|
|
|
"$themeDir/css/print_HomePage.css",
|
|
|
|
"$themeDir/css/print_Page.css",
|
|
|
|
);
|
|
|
|
|
|
|
|
Requirements::combine_files('print.css', $printStylesheets, 'print');
|
|
|
|
|
|
|
|
## Clearing assets
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::clear();
|
|
|
|
|
|
|
|
Clears all defined requirements. You can also clear specific requirements.
|
|
|
|
|
|
|
|
:::php
|
2014-10-30 05:16:38 +01:00
|
|
|
Requirements::clear(THIRDPARTY_DIR.'/prototype.js');
|
2014-10-13 09:49:30 +02:00
|
|
|
|
|
|
|
<div class="alert" markdown="1">
|
|
|
|
Depending on where you call this command, a Requirement might be *re-included* afterwards.
|
|
|
|
</div>
|
|
|
|
|
|
|
|
## Blocking
|
|
|
|
|
|
|
|
Requirements can also be explicitly blocked from inclusion, which is useful to avoid conflicting JavaScript logic or
|
|
|
|
CSS rules. These blocking rules are independent of where the `block()` call is made. It applies both for already
|
|
|
|
included requirements, and ones included after the `block()` call.
|
|
|
|
|
|
|
|
One common example is to block the core `jquery.js` added by various form fields and core controllers, and use a newer
|
|
|
|
version in a custom location. This assumes you have tested your application with the newer version.
|
|
|
|
|
|
|
|
:::php
|
|
|
|
Requirements::block(THIRDPARTY_DIR . '/jquery/jquery.js');
|
|
|
|
|
|
|
|
<div class="alert" markdown="1">
|
|
|
|
The CMS also uses the `Requirements` system, and its operation can be affected by `block()` calls. Avoid this by
|
|
|
|
limiting the scope of your blocking operations, e.g. in `init()` of your controller.
|
|
|
|
</div>
|
|
|
|
|
|
|
|
## Inclusion Order
|
|
|
|
|
|
|
|
Requirements acts like a stack, where everything is rendered sequentially in the order it was included. There is no way
|
|
|
|
to change inclusion-order, other than using *Requirements::clear* and rebuilding the whole set of requirements.
|
|
|
|
|
|
|
|
<div class="alert" markdown="1">
|
|
|
|
Inclusion order is both relevant for CSS and Javascript files in terms of dependencies, inheritance and overlays - be
|
|
|
|
careful when messing with the order of requirements.
|
|
|
|
</div>
|
|
|
|
|
|
|
|
## Javascript placement
|
|
|
|
|
|
|
|
By default, SilverStripe includes all Javascript files at the bottom of the page body, unless there's another script
|
|
|
|
already loaded, then, it's inserted before the first `<script>` tag. If this causes problems, it can be configured.
|
|
|
|
|
|
|
|
**mysite/_config/app.yml**
|
|
|
|
|
|
|
|
:::yml
|
|
|
|
Requirements:
|
|
|
|
write_js_to_body: true
|
|
|
|
force_js_to_bottom: true
|
|
|
|
|
|
|
|
`Requirements.force_js_to_bottom`, will force SilverStripe to write the Javascript to the bottom of the page body, even
|
|
|
|
if there is an earlier script tag.
|
|
|
|
|
|
|
|
|
|
|
|
## API Documentation
|
|
|
|
|
|
|
|
* [api:Requirements]
|