Since the laika frontend renders client-side we don't need a full templating engine anymore.

Acceptance criteria

• Replace Twig with a class that collects the variables similar to Twig and outputs them into the data attribute in the Vue mount point.
• Automatically map routes to JS entry points (replacing the individual JavaScript tags in current Twig templates).
• Replace unit test checks that check for a specific output with checks that look for specific assignments in the template context.

Notes

• The Twig template engine is still used in email templates.
• Unit (and edge-to-edge) tests need to be changed, as some of them are checking template output that use some test templates.
• Tests for the address change feature parses data attributes of the output.
• Looking at the class TwigTemplate might help understanding what's required.
• See the-silex-sunset for an example of how to create an event handler.

Possible Solution

3 SP

• Introduce implementation of the interface Template that has the methods render() and assign().
• Replace context array by calls to assign().
• Replace all references to TwigTemplate by references to Template.

5 SP

• All controllers must provide the entry point name to the templating engine.
• Introduce middleware that injects the JS entry point into the request by using Symfony's HttpEventHandler. We currently assume that we have a 1:1 mapping between routes and entry point names (some of the entry points being reused for several routes).
• (Change all calls to render() to provide the entry point name.)

13 SP

• Create phabricator board containing tasks for each route.
• Duplicate base_template.html.twig into [tbd.php].
• Go through all calls (step-by-step) of getLayoutTemplate() and replace by getNewLayoutTemplate() making sure that unit tests still pass or are fixed respectively.
• The Template implementation can have a getAssignedVariables() method to also be used in unit tests.
• Change the method name of getNewLayoutTemplate() back to getLayoutTemplate().