Symfony2和Twig-检查资产是否存在 [英] Symfony2 and Twig - Check if an asset exists
问题描述
我有一个使用树枝模板的symfony2项目.
I have a symfony2 project using twig templates.
我正在显示一些图像,并且仅在存在特定资产的情况下才显示图像.
I am displaying some images and would like to display the image only if the specific asset exists.
我有这个:
{% if asset('bundles/sciforumversion2/images/logos/'~conf.img) %}
<img style="width: 60px; float:right; margin-right: 15px;" src="{{ asset('bundles/sciforumversion2/images/logos/')}}{{ conf.img }}"/>
{% endif %}
但是if条件始终为真.
But the if condition is always true.
有什么主意吗?谢谢.
推荐答案
If you want to check if an asset exists, you can create a Twig extension to implement the function.
PHP 在您的Twig\Extension
目录中,创建具有以下内容的AssetExistsExtension.php
:
PHP In your Twig\Extension
directory, create AssetExistsExtension.php
with the following content:
<?php
namespace Fuz\TestBundle\Twig\Extension;
use Symfony\Component\HttpKernel\KernelInterface;
class AssetExistsExtension extends \Twig_Extension
{
private $kernel;
public function __construct(KernelInterface $kernel)
{
$this->kernel = $kernel;
}
public function getFunctions()
{
return array(
'asset_exists' => new \Twig_Function_Method($this, 'asset_exists'),
);
}
public function asset_exists($path)
{
$webRoot = realpath($this->kernel->getRootDir() . '/../web/');
$toCheck = realpath($webRoot . $path);
// check if the file exists
if (!is_file($toCheck))
{
return false;
}
// check if file is well contained in web/ directory (prevents ../ in paths)
if (strncmp($webRoot, $toCheck, strlen($webRoot)) !== 0)
{
return false;
}
return true;
}
public function getName()
{
return 'asset_exists';
}
}
YML 这是要放入您的services.yml
文件的配置.
YML And here is the configuration, to put in your services.yml
file.
parameters:
(...)
fuz_tools.twig.asset_exists_extension.class: Fuz\TestBundle\Twig\Extension\Asset@ExistsExtension
services:
(...)
fuz_tools.twig.asset_exists_extension:
class: '%fuz_tools.twig.asset_exists_extension.class%'
arguments: ['@kernel']
tags:
- { name: twig.extension }
Twig 要在树枝文件上使用此扩展名,请使用:
Twig To use this extension, on a twig file, use:
{% if asset_exists('bundles/fuztest/images/test.png') %}
注意:请不要忘记替换名称空间以与您的项目匹配.
Note: do not forget to replace namespaces to match with your project.
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