发布于 2015-08-27 16:48:06 | 157 次阅读 | 评论: 0 | 来源: 网络整理
Symfony defaults to Twig for its template engine, but you can still use plain PHP code if you want. Both templating engines are supported equally in Symfony. Symfony adds some nice features on top of PHP to make writing templates with PHP more powerful.
If you want to use the PHP templating engine, first, make sure to enable it in your application configuration file:
# app/config/config.yml
framework:
# ...
templating:
engines: ['twig', 'php']
<!-- app/config/config.xml -->
<framework:config>
<!-- ... -->
<framework:templating>
<framework:engine id="twig" />
<framework:engine id="php" />
</framework:templating>
</framework:config>
$container->loadFromExtension('framework', array(
// ...
'templating' => array(
'engines' => array('twig', 'php'),
),
));
You can now render a PHP template instead of a Twig one simply by using the
.php extension in the template name instead of .twig. The controller
below renders the index.html.php template:
// src/AppBundle/Controller/HelloController.php
// ...
public function indexAction($name)
{
return $this->render(
'AppBundle:Hello:index.html.php',
array('name' => $name)
);
}
You can also use the @Template shortcut to render the default
AppBundle:Hello:index.html.php template:
// src/AppBundle/Controller/HelloController.php
use SensioBundleFrameworkExtraBundleConfigurationTemplate;
// ...
/**
* @Template(engine="php")
*/
public function indexAction($name)
{
return array('name' => $name);
}
警告
Enabling the php and twig template engines simultaneously is
allowed, but it will produce an undesirable side effect in your application:
the @ notation for Twig namespaces will no longer be supported for the
render() method:
public function indexAction()
{
// ...
// namespaced templates will no longer work in controllers
$this->render('@App/Default/index.html.twig');
// you must use the traditional template notation
$this->render('AppBundle:Default:index.html.twig');
}
{# inside a Twig template, namespaced templates work as expected #}
{{ include('@App/Default/index.html.twig') }}
{# traditional template notation will also work #}
{{ include('AppBundle:Default:index.html.twig') }}
More often than not, templates in a project share common elements, like the well-known header and footer. In Symfony, this problem is thought about differently: a template can be decorated by another one.
The index.html.php template is decorated by layout.html.php, thanks to
the extend() call:
<!-- src/AppBundle/Resources/views/Hello/index.html.php -->
<?php $view->extend('AppBundle::layout.html.php') ?>
Hello <?php echo $name ?>!
The AppBundle::layout.html.php notation sounds familiar, doesn’t it? It
is the same notation used to reference a template. The :: part simply
means that the controller element is empty, so the corresponding file is
directly stored under views/.
Now, have a look at the layout.html.php file:
<!-- src/AppBundle/Resources/views/layout.html.php -->
<?php $view->extend('::base.html.php') ?>
<h1>Hello Application</h1>
<?php $view['slots']->output('_content') ?>
The layout is itself decorated by another one (::base.html.php). Symfony
supports multiple decoration levels: a layout can itself be decorated by
another one. When the bundle part of the template name is empty, views are
looked for in the app/Resources/views/ directory. This directory stores
global views for your entire project:
<!-- app/Resources/views/base.html.php -->
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title><?php $view['slots']->output('title', 'Hello Application') ?></title>
</head>
<body>
<?php $view['slots']->output('_content') ?>
</body>
</html>
For both layouts, the $view['slots']->output('_content') expression is
replaced by the content of the child template, index.html.php and
layout.html.php respectively (more on slots in the next section).
As you can see, Symfony provides methods on a mysterious $view object. In
a template, the $view variable is always available and refers to a special
object that provides a bunch of methods that makes the template engine tick.
A slot is a snippet of code, defined in a template, and reusable in any layout
decorating the template. In the index.html.php template, define a
title slot:
<!-- src/AppBundle/Resources/views/Hello/index.html.php -->
<?php $view->extend('AppBundle::layout.html.php') ?>
<?php $view['slots']->set('title', 'Hello World Application') ?>
Hello <?php echo $name ?>!
The base layout already has the code to output the title in the header:
<!-- app/Resources/views/base.html.php -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title><?php $view['slots']->output('title', 'Hello Application') ?></title>
</head>
The output() method inserts the content of a slot and optionally takes a
default value if the slot is not defined. And _content is just a special
slot that contains the rendered child template.
For large slots, there is also an extended syntax:
<?php $view['slots']->start('title') ?>
Some large amount of HTML
<?php $view['slots']->stop() ?>
The best way to share a snippet of template code is to define a template that can then be included into other templates.
Create a hello.html.php template:
<!-- src/AppBundle/Resources/views/Hello/hello.html.php -->
Hello <?php echo $name ?>!
And change the index.html.php template to include it:
<!-- src/AppBundle/Resources/views/Hello/index.html.php -->
<?php $view->extend('AppBundle::layout.html.php') ?>
<?php echo $view->render('AppBundle:Hello:hello.html.php', array('name' => $name)) ?>
The render() method evaluates and returns the content of another template
(this is the exact same method as the one used in the controller).
And what if you want to embed the result of another controller in a template? That’s very useful when working with Ajax, or when the embedded template needs some variable not available in the main template.
If you create a fancy action, and want to include it into the
index.html.php template, simply use the following code:
<!-- src/AppBundle/Resources/views/Hello/index.html.php -->
<?php echo $view['actions']->render(
new SymfonyComponentHttpKernelControllerControllerReference('AppBundle:Hello:fancy', array(
'name' => $name,
'color' => 'green',
))
) ?>
Here, the AppBundle:Hello:fancy string refers to the fancy action of the
Hello controller:
// src/AppBundle/Controller/HelloController.php
class HelloController extends Controller
{
public function fancyAction($name, $color)
{
// create some object, based on the $color variable
$object = ...;
return $this->render('AppBundle:Hello:fancy.html.php', array(
'name' => $name,
'object' => $object
));
}
// ...
}
But where is the $view['actions'] array element defined? Like
$view['slots'], it’s called a template helper, and the next section tells
you more about those.
The Symfony templating system can be easily extended via helpers. Helpers are
PHP objects that provide features useful in a template context. actions and
slots are two of the built-in Symfony helpers.
Speaking of web applications, creating links between pages is a must. Instead
of hardcoding URLs in templates, the router helper knows how to generate
URLs based on the routing configuration. That way, all your URLs can be easily
updated by changing the configuration:
<a href="<?php echo $view['router']->generate('hello', array('name' => 'Thomas')) ?>">
Greet Thomas!
</a>
The generate() method takes the route name and an array of parameters as
arguments. The route name is the main key under which routes are referenced
and the parameters are the values of the placeholders defined in the route
pattern:
# src/AppBundle/Resources/config/routing.yml
hello: # The route name
path: /hello/{name}
defaults: { _controller: AppBundle:Hello:index }
What would the Internet be without images, JavaScripts, and stylesheets?
Symfony provides the assets tag to deal with them easily:
<link href="<?php echo $view['assets']->getUrl('css/blog.css') ?>" rel="stylesheet" type="text/css" />
<img src="<?php echo $view['assets']->getUrl('images/logo.png') ?>" />
The assets helper’s main purpose is to make your application more
portable. Thanks to this helper, you can move the application root directory
anywhere under your web root directory without changing anything in your
template’s code.
By using the stopwatch helper, you are able to time parts of your template
and display it on the timeline of the WebProfilerBundle:
<?php $view['stopwatch']->start('foo') ?>
... things that get timed
<?php $view['stopwatch']->stop('foo') ?>
小技巧
If you use the same name more than once in your template, the times are grouped on the same line in the timeline.
When using PHP templates, escape variables whenever they are displayed to the user:
<?php echo $view->escape($var) ?>
By default, the escape() method assumes that the variable is outputted
within an HTML context. The second argument lets you change the context. For
instance, to output something in a JavaScript script, use the js context:
<?php echo $view->escape($var, 'js') ?>