发布于 2015-08-27 16:47:05 | 176 次阅读 | 评论: 0 | 来源: 网络整理
警告
The YUI Compressor is no longer maintained by Yahoo. That’s why you are strongly advised to avoid using YUI utilities unless strictly necessary. Read 如何压缩CSS/JS文件（使用UglifyJS和UglifyCSS） for a modern and up-to-date alternative.
Yahoo! provides an excellent utility for minifying JavaScripts and stylesheets so they travel over the wire faster, the YUI Compressor. Thanks to Assetic, you can take advantage of this tool very easily.
The YUI Compressor is written in Java and distributed as a JAR. Download the JAR
from the Yahoo! site and save it to app/Resources/java/yuicompressor.jar.
Now you need to configure two Assetic filters in your application, one for minifying JavaScripts with the YUI Compressor and one for minifying stylesheets:
# app/config/config.yml
assetic:
# java: "/usr/bin/java"
filters:
yui_css:
jar: "%kernel.root_dir%/Resources/java/yuicompressor.jar"
yui_js:
jar: "%kernel.root_dir%/Resources/java/yuicompressor.jar"
<!-- app/config/config.xml -->
<assetic:config>
<assetic:filter
name="yui_css"
jar="%kernel.root_dir%/Resources/java/yuicompressor.jar" />
<assetic:filter
name="yui_js"
jar="%kernel.root_dir%/Resources/java/yuicompressor.jar" />
</assetic:config>
// app/config/config.php
$container->loadFromExtension('assetic', array(
// 'java' => '/usr/bin/java',
'filters' => array(
'yui_css' => array(
'jar' => '%kernel.root_dir%/Resources/java/yuicompressor.jar',
),
'yui_js' => array(
'jar' => '%kernel.root_dir%/Resources/java/yuicompressor.jar',
),
),
));
注解
Windows users need to remember to update config to proper Java location.
In Windows7 x64 bit by default it’s C:Program Files (x86)Javajre6binjava.exe.
You now have access to two new Assetic filters in your application:
yui_css and yui_js. These will use the YUI Compressor to minify
stylesheets and JavaScripts, respectively.
You have YUI Compressor configured now, but nothing is going to happen until you apply one of these filters to an asset. Since your assets are a part of the view layer, this work is done in your templates:
{% javascripts '@AppBundle/Resources/public/js/*' filter='yui_js' %}
<script src="{{ asset_url }}"></script>
{% endjavascripts %}
<?php foreach ($view['assetic']->javascripts(
array('@AppBundle/Resources/public/js/*'),
array('yui_js')
) as $url): ?>
<script src="<?php echo $view->escape($url) ?>"></script>
<?php endforeach ?>
注解
The above example assumes that you have a bundle called AppBundle and your
JavaScript files are in the Resources/public/js directory under your
bundle. This isn’t important however - you can include your JavaScript
files no matter where they are.
With the addition of the yui_js filter to the asset tags above, you should
now see minified JavaScripts coming over the wire much faster. The same process
can be repeated to minify your stylesheets.
{% stylesheets '@AppBundle/Resources/public/css/*' filter='yui_css' %}
<link rel="stylesheet" type="text/css" media="screen" href="{{ asset_url }}" />
{% endstylesheets %}
<?php foreach ($view['assetic']->stylesheets(
array('@AppBundle/Resources/public/css/*'),
array('yui_css')
) as $url): ?>
<link rel="stylesheet" type="text/css" media="screen" href="<?php echo $view->escape($url) ?>" />
<?php endforeach ?>
Minified JavaScripts and Stylesheets are very difficult to read, let alone
debug. Because of this, Assetic lets you disable a certain filter when your
application is in debug mode. You can do this by prefixing the filter name
in your template with a question mark: ?. This tells Assetic to only
apply this filter when debug mode is off.
{% javascripts '@AppBundle/Resources/public/js/*' filter='?yui_js' %}
<script src="{{ asset_url }}"></script>
{% endjavascripts %}
<?php foreach ($view['assetic']->javascripts(
array('@AppBundle/Resources/public/js/*'),
array('?yui_js')
) as $url): ?>
<script src="<?php echo $view->escape($url) ?>"></script>
<?php endforeach ?>
小技巧
Instead of adding the filter to the asset tags, you can also globally
enable it by adding the apply_to attribute to the filter configuration, for
example in the yui_js filter apply_to: ".js$". To only have the filter
applied in production, add this to the config_prod file rather than the
common config file. For details on applying filters by file extension,
see Filtering Based on a File Extension.