In Twig 2.x, _self is a string instead of a Template instance

[javiereguiluz]

In the templates of this application we use the following to display the source code of the current Twig template:

{{ show_source_code(_self) }}

However, Twig 2.x changed the _self variable and now it only returns a string of the template path instead of the Template object instance.

We should change/improve this feature to make the application compatible with Symfony 3.

[voronkovich]

As a solution I would suggest #254, because for now _self is useless and looks very strange for the newcomers.

[stof]

Title is wrong. It is about Twig 2. Migrating to Symfony 3 has nothing to do here

[stof]

@voronkovich there is a much simpler way. See my PR.