Opened 2 years ago
Closed 2 years ago
#33943 closed New feature (needsinfo)
Add django.template.Engine.get_default_backend for easier access to backend methods
Reported by: | Peter Thomassen | Owned by: | nobody |
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Component: | Template system | Version: | 4.1 |
Severity: | Normal | Keywords: | |
Cc: | Triage Stage: | Unreviewed | |
Has patch: | yes | Needs documentation: | no |
Needs tests: | no | Patch needs improvement: | no |
Easy pickings: | no | UI/UX: | no |
Description
Assume that the task is to create a template from string using DjangoTemplates.from_string() of the default template backend.
(This has the special feature that the result of Engine.from_string() is wrapped to construct an instance of the Template class defined in the backend definition file: django/template/backends/django.py#30 This Template class differs from the Engine-delivered Template in that it accepts a dictionary as the context, see https://docs.djangoproject.com/en/4.1/topics/templates/#django.template.backends.base.Template.render.)
The problem is that it is difficult to retrieve the default template backend in order to call .from_string() on it. However, a function already exists to retrieve the default template backend's *engine*.
The default backend's engine is retrieved via django.template.Engine.get_default(). This function identifies the first configured DjangoTemplates backend, and then returns its .engine attribute. As a result, when from_string() is called, it will be called on the engine and not on the backend, thus the wrapping Template() call is missing.
I am proposing to add a get_default_backend() function to django.template.Engine, which is like get_default(), but returns the backend itself (and not its .engine attribute). This would allow calling .from_string() directly on the backend subsequently. -- get_default() can then be adjusted to simply return get_default_backend().engine.
While trying to solve the issue (context argument type mismatch: dict vs Context), I found the docs not very helpful, as they are not very accurate in the distinction between a backend and its engine. I've also added a commit that clarifies that language.
I have submitted a patch here: https://github.com/django/django/pull/15944
For discussion on the list, see here: https://groups.google.com/g/django-developers/c/BfB9QsDMMAI
I'll close as needsinfo pending the mailing list discussion. (We can reopen if we decide to progress.) Thanks.