Symfony2 FOSRESTBundle REST API to return PDF

我在里面制作了一个Bundle和一个REST控制器。"index"方法返回JSON格式的数组，可以：

MyBundle/Controller/Api/Rest/BaconController.php

class BaconController extends Controller implements ClassResourceInterface
{
    /**
     * @var Request $request
     * @return array
     * @Rest'View
     */
    public function cgetAction(Request $request)
    {
        $mediaType = $request->attributes->get('media_type');
        $format = $request->getFormat($mediaType);
        my_dump($format);
        return array(
             array("id" => 1, "title" => "hello",),
             array("id" => 2, "title" => "there",),
        );
    }
}

MyBundle/Resources/config/api/routing_rest.yml

my_api_rest_bacon:
    type: rest
    resource: "MyBundle:Api/Rest/Bacon"
    name_prefix: api_rest_bacon_
    prefix: /my/bacon

因此，在这一点上，JSON结果得到了完美的返回：

mysite.com/app_dev.php/api/my/bacon/bacons.json

返回我的数组。

但现在我需要让我的控制器用数据生成一个PDF。所以我希望它在我打电话时返回PDF文档：

mysite.com/app_dev.php/api/my/bacon/bacons.pdf

我发现了一些半手册：RSS视图处理程序、RSS配置、CSV问题和答案。并试图制造类似的东西：

我已将这些行添加到

Symfony/app/config/config.yml

framework:
    [...some old stuff here...]
    request:
        formats:
            pdf: 'application/pdf'
fos_rest:
    body_converter:
        enabled:              true
    format_listener:
        rules:
            # Prototype array
            -
                # URL path info
                path:                 ~
                # URL host name
                host:                 ~
                prefer_extension:     true
                fallback_format:      html
                priorities:           [html,json]
            -
                path:                 ~
                host:                 ~
                prefer_extension:     true
                fallback_format:      pdf
                priorities:           [pdf]
    view:
        # @View or @Template
        view_response_listener: force #true
        formats:
            json: true
            pdf: true
            xls: true
            html: false
        templating_formats:
            pdf: false
            xls: false
        mime_types: {'pdf': ['application/pdf']}
    routing_loader:
        default_format: html
    param_fetcher_listener: true
    body_listener: true
    allowed_methods_listener: true
services:
    my.view_handler.pdf:
        class: Lobster'MyBundle'View'PdfViewHandler
    my.view_handler:
        parent: fos_rest.view_handler.default
        calls:
            - ['registerHandler', [ 'pdf', [@my.view_handler.pdf, 'createResponse'] ] ]

MyBundle/View/PdfViewHandler.php

namespace Lobster'MyBundle'View;
use FOS'RestBundle'View'View;
use FOS'RestBundle'View'ViewHandler;
use Symfony'Component'HttpFoundation'Request;
use Symfony'Component'HttpFoundation'Response;
class PdfViewHandler
{
    public function createResponse(ViewHandler $handler, View $view, Request $request, $format)
    {
        my_dump('pdf createResponse started');
        $pdf = "some pdf";
        return new Response($pdf, 200, $view->getHeaders());
    }
}

所以现在当我打电话给

mysite.com/app_dev.php/api/my/bacon/bacons.pdf

我看到一个错误An Exception was thrown while handling: Format html not supported, handler must be implemented，我的函数my_dump将有关文件格式的信息保存到一个文本文件中：它是html，而不是pdf。

pdf createResponse也不起作用。为什么？