docs: clarify load rerun behavior

[coryvirok]

Based on the conversations here:

• Layout invalidated when referencing missing search param #10504
• Invalidate url and searchParams separately #8403

Any changes to the URL will cause any load functions that access url.searchParams to be rerun even if the search portion of the URL has not changed (or indeed if there are no search params in the URL.)

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[benmccann]

hmm. are we sure this isn't a bug? I don't think we should document it if the behavior is unexpected / wrong

[coryvirok]

I think the consensus is that this is a bug but the fix is not yet planned. Maybe we can document it but highlight it as a bug and link to the GH issues? The challenge with not documenting the current behavior is that it's fairly difficult to find unless you know what to look for, e.g. "load", "invalidate", "url.searchParams", etc. in GH.

I'm hoping that the priority for a fix is elevated since the original bug addressed changing search params that were supposed to be handled by different layouts and the bug I filed is a more generic (and IMO more likely to occur) issue that happens even if the search param is not provided at all.

cc @dummdidumm

[benmccann]

I don't think we want to add something to the docs for every issue that's in the issue tracker. It'd be better to just fix the issue

[coryvirok]

Any update on if this issue is on the roadmap? This is blocking some advanced functionality for my app and I cannot find a way around it without needing to change the pathname structure of my URLs, (in order to move the search param into a route param.)

The linked issue has it as low priority - p3-edge-case.