Create a route on symfony based on a json body - php

Question

My goal is to have a route that if the body which is a json string contains the string "type":"pay" to apply the route.
I tried this:
/*
* #Route(
* path="/myfunction",
* condition="request.getContent() matches '/\\b\\"type\\":\\"pay\\"\\b/i'"
* )
*/
But until now I get exception because when it finds the double quote " before type it thinks that the condition part should be over.
And I get exception like this:
Caused by
Symfony\Component\Config\Exception\FileLoaderLoadException: [Syntax Error] Expected Doctrine\Common\Annotations\DocLexer::T_CLOSE_PARENTHESIS, got 'type' at position 147
Until now I tried the following
condition="request.getContent() matches '/\\b"type":"pay"\\b/i'"
condition="request.getContent() matches '/\\b\"type\":\"pay\"\b/i'"
condition="request.getContent() matches '/\\b\\\\\\\\"type\\\\\\\\":\\\\\\\\"pay\\\\\\\\"\\b/i'"
According to the documentation http://symfony.com/doc/3.4/components/expression_language/syntax.html
I am using symfony 3.4

Answer 1

What you could do, is create an EventListener that listens to the kernel.request-event and has a priority that puts it before Symfony's RouterListener::onKernelRequest() for finding routes.
In this custom listener you can add an attribute to the request, which you can fill with the data from the request body. It could look something like this:
public function onKernelRequest(GetResponseEvent $event)
{
$request = $event->getRequest();
// Maybe abort before reading content, if we don't expect a JSON-body
$jsonEncodedContent = $request->getContent();
// Decode JSON, validate
$request->attributes->set('content_type', ...);
}
Then in your route you should be able to access this attribute instead of reading the json body, you can access this attribute:
condition="request.attributes.content_type == 'pay'"
The downside to this approach is, that your listener must run at the right point, which might cause some issues later on as it's hard to test for this, and this might be hard to find and understand for new developers on your project.