Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Remove context None guard exception #30

Open
wants to merge 4 commits into
base: main
Choose a base branch
from
Open
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 0 additions & 3 deletions laces/components.py
Original file line number Diff line number Diff line change
Expand Up @@ -45,9 +45,6 @@ def render_html(
`django.utils.safestring.SafeString` instance.
"""
context_data = self.get_context_data(parent_context)
if context_data is None:
raise TypeError("Expected a dict from get_context_data, got None")

template = get_template(self.template_name)
return template.render(context_data)

Expand Down
27 changes: 18 additions & 9 deletions laces/tests/test_components.py
Original file line number Diff line number Diff line change
Expand Up @@ -156,17 +156,24 @@ def test_render_html_when_get_context_data_returns_None(self) -> None:
"""
Test `render_html` method when `get_context_data` returns `None`.

The `render_html` method raises a `TypeError` when `None` is returned from
`get_context_method`. This behavior was present when the class was extracted
from Wagtail. It is not totally clear why this specific check is needed. By
default, the `get_context_data` method provides and empty dict. If an override
wanted to `get_context_data` return `None`, it should be expected that no
context data is available during rendering. The underlying `template.render`
method does not seem to be ok with `None` as the provided context.
Originally, the `render_html` method explicitly raised a `TypeError` when
`None` was returned from `get_context_method`.

I was not able to find out why this check was put in place. The components usage
in Wagtail does not reveal any issues when the error is removed. Also, the
Copy link
Owner Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
in Wagtail does not reveal any issues when the error is removed. Also, the
in Wagtail does not reveal any issues when the error guard is removed.
Also, the

following template rendering works just fine with the context being `None`.
Copy link
Owner Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
following template rendering works just fine with the context being `None`.
template rendering with `template.render(context)` works just fine with the context being `None`.


It seems therefore safe to assume that this was a left-over without much current
need.

This test is in place to prove that a component can behave as expected when the
`get_context_data` method returns `None`.
"""

# -----------------------------------------------------------------------------
class ExampleComponent(Component):
template_name = self.example_template_name

def get_context_data(
self,
parent_context: "Optional[RenderContext]" = None,
Expand All @@ -175,9 +182,11 @@ def get_context_data(
return None

# -----------------------------------------------------------------------------
self.set_example_template_content("Hello")

result = ExampleComponent().render_html()

with self.assertRaises(TypeError):
ExampleComponent().render_html()
self.assertEqual(result, "Hello")

def test_media_defined_through_nested_class(self) -> None:
"""
Expand Down
Loading