use blueprint specified template folder

[alanhamlett]

Fixes issue #1361.

[svieira]

Unless I am greatly mistaken this will break anyone out there who is using extensions and overriding (not inheriting from) the extension's blueprints. For example, given the following extension setup:

extension/
    __init__.py
    some.py
    extension_details.py
    templates/
        extension/
            base.html
            some-page.html

before this patch, overriding base.html would simply have been a matter of:

the-app/
    __init__.py
    templates/
        the-layout.html
        extension/
            base.html

And making sure that base.html@the-app had the necessary block and import declarations. This would shadow base.html@extension, allowing the app developer to override what the extension was doing without the extension developer having to provide a hook for such an overload

With this patch, I don't think there is a way to override base.html@extension in extension without patching Flask to bring back the old behavior (which will result in a lot of issues if new extensions start depending on this behavior).

[davidism]

Agree with @svieira, this is the point I was making in my comment on the original issue.

The point of searching the app template folder first is so that an app developer can override templates supplied by a blueprint from an extension.

[ThiefMaster]

Those commits should be squashed into a single one eventually.

Also, this would be a breaking change depending on the application structure, so I'd rather make it configurable, with the current behavior being the default.

[svieira]

If configurable it would have to be done at the register_blueprint method (since you could have one extension looking for the old behavior and one needed the new behavior).

I created #1548 to talk about some another possibility that might solve several of these issues in one go.

[N0odlez]

Is there any update on when this fix could be merged or implemented in a different manner?

[davidism]

The referenced issue was closed as wontfix.