Twig_Error_Syntax：未知的“template_from_string”函数。 功能过时了吗？

Question

我记得在 Composer 更新后我得到了这个错误，但以前它工作得很好，在比较软件包版本时我没有发现差异。 我在模板中以这种方式使用它：

{{ include(template_from_string(page.body)) }}

其中“页面”是来自控制器的实体对象。 当前版本是：

symfony/symfony                          v2.8.15
twig/extensions                          v1.4.1
twig/twig                                v1.30.0

同样在 config.yml 中：

twig:
    debug:            "%kernel.debug%"
    strict_variables: "%kernel.debug%"
    form_themes:
        - 'AppBundle::Form/form_override.html.twig'

现在在vendor/twig/twig/lib/twig/Twig/Extension/StringLoader.php视觉上正确的文件，但似乎仍然无法正常工作。 完整的堆栈跟踪：

[1] Twig_Error_Syntax: Unknown "template_from_string" function.
    at n/a
        in ProjectDir\src\AppBundle/Resources/views/Page.html.twig line 22

    at Twig_ExpressionParser->getFunctionNodeClass('template_from_string', '22')
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 374

    at Twig_ExpressionParser->getFunctionNode('template_from_string', '22')
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 162

    at Twig_ExpressionParser->parsePrimaryExpression()
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 102

    at Twig_ExpressionParser->getPrimary()
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 55

    at Twig_ExpressionParser->parseExpression()
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 520

    at Twig_ExpressionParser->parseArguments(true)
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 373

    at Twig_ExpressionParser->getFunctionNode('include', '22')
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 162

    at Twig_ExpressionParser->parsePrimaryExpression()
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 102

    at Twig_ExpressionParser->getPrimary()
        in ProjectDir\vendor\twig\twig\lib\Twig\ExpressionParser.php line 55

    at Twig_ExpressionParser->parseExpression()
        in ProjectDir\vendor\twig\twig\lib\Twig\Parser.php line 147

    at Twig_Parser->subparse(array(object(Twig_TokenParser_Block), 'decideBlockEnd'), true)
        in ProjectDir\vendor\twig\twig\lib\Twig\TokenParser\Block.php line 40

    at Twig_TokenParser_Block->parse(object(Twig_Token))
        in ProjectDir\vendor\twig\twig\lib\Twig\Parser.php line 190

    at Twig_Parser->subparse(null, false)
        in ProjectDir\vendor\twig\twig\lib\Twig\Parser.php line 103

    at Twig_Parser->parse(object(Twig_TokenStream))
        in ProjectDir\app\cache\dev\classes.php line 3415

    at Twig_Environment->parse(object(Twig_TokenStream))
        in ProjectDir\app\cache\dev\classes.php line 3443

    at Twig_Environment->compileSource(object(Twig_Source))
        in ProjectDir\app\cache\dev\classes.php line 3291

    at Twig_Environment->loadTemplate('AppBundle::Page.html.twig')
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bridge\Twig\TwigEngine.php line 126

    at Symfony\Bridge\Twig\TwigEngine->load('AppBundle::Page.html.twig')
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bridge\Twig\TwigEngine.php line 50

    at Symfony\Bridge\Twig\TwigEngine->render('AppBundle::Page.html.twig', array('page' => object(Page), 'ads' => array(object(VertBanner), object(VertBanner)), 'slug' => 'direktor'))
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bundle\TwigBundle\TwigEngine.php line 72

    at Symfony\Bundle\TwigBundle\TwigEngine->render('AppBundle::Page.html.twig', array('page' => object(Page), 'ads' => array(object(VertBanner), object(VertBanner)), 'slug' => 'direktor'))
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bundle\TwigBundle\TwigEngine.php line 103

    at Symfony\Bundle\TwigBundle\TwigEngine->renderResponse('AppBundle::Page.html.twig', array('page' => object(Page), 'ads' => array(object(VertBanner), object(VertBanner)), 'slug' => 'direktor'), null)
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bundle\FrameworkBundle\Controller\Controller.php line 185

    at Symfony\Bundle\FrameworkBundle\Controller\Controller->render('AppBundle::Page.html.twig', array('page' => object(Page), 'ads' => array(object(VertBanner), object(VertBanner)), 'slug' => 'direktor'))
        in ProjectDir\src\AppBundle\Controller\PageController.php line 35

    at AppBundle\Controller\PageController->getPageAction('direktor')
        in  line 

    at call_user_func_array(array(object(PageController), 'getPageAction'), array('direktor'))
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Component\HttpKernel\HttpKernel.php line 144

    at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), '1')
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Component\HttpKernel\HttpKernel.php line 64

    at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), '1', true)
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Component\HttpKernel\DependencyInjection\ContainerAwareHttpKernel.php line 69

    at Symfony\Component\HttpKernel\DependencyInjection\ContainerAwareHttpKernel->handle(object(Request), '1', true)
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Component\HttpKernel\Kernel.php line 185

    at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
        in ProjectDir\web\app_dev.php line 28

    at require('ProjectDir\web\app_dev.php')
        in ProjectDir\vendor\symfony\symfony\src\Symfony\Bundle\FrameworkBundle\Resources\config\router_dev.php line 40

Answer 1

您必须让服务容器知道您的 Twig 扩展：

# app/config/services.yml
acme.twig.extension.loader:
    class:        Twig_Extension_StringLoader
    tags:
         - { name: 'twig.extension' }

Symfony 4：

# config/services.yml
app.twig.extension.loader:
    class: Twig\Extension\StringLoaderExtension
    tags:
        - { name: 'twig.extension' }

Answer 2

对于 symfony5 和 twig3，这里的答案有效： Symfony 4: Add Twig_Extension_StringLoader

# config/services.yaml
services:
    Twig\Extension\StringLoaderExtension:

由于这在谷歌中更容易找到，我将在此处添加。