How to intercept the call to a service method in Symfony2?

Question

I want to intercept a call to a Service method and execute some code before it.

For example, someone wrote:

$this->container->get('file_locator')->isAbsolutePath($path);

I want to intercept the call to Symfony\\Component\\Config\\FileLocator::isAbsolutePath() and execute some code before it.

Is that possible?

Thanks

Answer 1

I'm not aware of a way to achieve exactly what you are looking for, but I can think of two methods that you should be able to use to achieve the same effect:

And then you have two options:

1. Override service

You could override the service with your own service which extends default one and overrides isAbsolutePath() method.

Override default FileLocator class with your own:

class MyCustomFileLocator extends FileLocator
{
    public function isAbsolutePath()
    {
        // Your awesome code here...
        return parent::isAbsolutePath();
    }
}

And override service definition:

# services.yml

# Just create a new definition with the same name

services:
    file_locator:
        class: MyCustomFileLocator
        arguments: [...]

# Or alternatively, if you're overriding one of symfony/third bundle services, 
# they often provide class parameter which can be overriden

parameters:
    file_locator.class: MyCustomFileLocator

2. Decorate service (Symfony >= 2.5)

You can use service decoration techinque , which will yield the same effect, but you will still have reference to original service as file_locator.inner if you need that for some reason.