use_context in the data function of a LazyRoute

[jhoobergs]

Is using use_context not supported in the data function of a LazyRoute? The context is not available when I request it in the data function, while it works fine if I move the use_context to the view function.

Ideally it would be possible to get the context in the data function, as I need the context within a Resource defined in the data function. For now, I have moved this resource to the view function, which works fine, but this potentially reduces performance somewhat.

[gbj]

Could you provide example code? Where is the context provided, relative to where it's used?

[jhoobergs]

I have reproduced the issue in the lazy_routes example. See jhoobergs@523fbc3 The page D view works and D data does not. The C view and C data pages show that no issue occurs in the situation with no nested lazy routes and where the context is provided outside of a lazy route.

The issue only seems to arise with nested Lazy routes, and when the context is provided within the outer lazy route.

[gbj]

It is working as designed in your reproduction, unless I'm misreading it; providing context in the view of a parent LazyRoute and consuming it in the data of the child LazyRoute is not intended to work. Supporting that would preventing loading the data for all routes concurrently, which is the point of splitting things into data and view functions in the first place.

Currently, the example loads ViewD data, ViewE data, ViewD lazy view, and ViewE lazy view concurrently, then renders the page once all have loaded.

Allowing ViewE data to read from context provided in ViewD view would create a waterfall:

• Load ViewD data, ViewD lazy view, and ViewE lazy view concurrently
• Wait for ViewD data and view to finish loading
• Render ViewD lazy view with ViewD data, in case it provides context
• Then start loading ViewE data in a second step, and wait for it to finish
• Then render the page

[jhoobergs]

Ok, thanks for the explanation.