Improve AnyScope API

[AaronErhardt]

Description

• Improve documentation
• Add try_downcast method to AnyScope
• Make find_parent_scope public. It could be used to find a parent component and send a message to it.

Checklist

• I have run cargo make pr-flow
• I have reviewed my own code
• I have added tests

[hamza1311]

Make find_parent_scope public. It could be used to find a parent component and send a message to it.

Is there a reason you need this? I don't mind increasing the public API but I would like to avoid doing it for no reason.

[github-actions]

Visit the preview URL for this PR (updated for commit ae73adf):

https://yew-rs-api--pr2445-scope-improvements-dsua3146.web.app

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[AaronErhardt]

I have an application that is structured into many small components that represent parts of a (kind of huge) questionnaire. They all write the changes to the same state (using a context provider) that stores the whole data of the questionnaire. When changes occur, the data is synced automatically with the database including visual feedback that the sync operation was successful. Currently, the synchronization is handled by a component that's the parent (or the parent's parent) of the individual questionnaire parts. I just need to send it a sync message. However, to send it a message, I need to use a lot of scope.get_parent().unwrap().get_parent().unwrap().downcast().

try_downcast would be enough to implement something like find_parent_scope manually but since it's already in the private API I though it could be exposed directly.

Possibly, my implementation is just unidiomatic, but it does the job pretty well apart from the code that tries to get the correct parent component.

[hamza1311]

Looks good. I understand the reasons to expose this, sounds reasonable to me. I'll leave the final decision to @siku2