push_patch just query changes

[LostKobrakai]

Environment

• Elixir version (elixir -v): 1.10
• Phoenix version (mix deps): 1.4
• Phoenix LiveView version (mix deps): 0.13.3
• NodeJS version (node -v):
• NPM version (npm -v):
• Operating system:
• Browsers you attempted to reproduce this bug on (the more the merrier):
• Does the problem persist after removing "assets/node_modules" and trying again? Yes/no:

Actual behavior

When doing {:noreply, push_patch(socket, to: "?page=1")} in a liveview callback I get an raised error:

** (ArgumentError) the :to option in push_patch/2 expects a path but was "?page=1"
    (phoenix_live_view 0.13.3) lib/phoenix_live_view.ex:2177: Phoenix.LiveView.raise_invalid_local_url!/2
    …

Expected behavior

The same href works when used with live_patch in my pagination template so it should work for push_patch as well. Given query strings can't change the mounted liveview module I can't see the need for knowing the path and consulting the router.

Additionally I'm wondering if there's merit in an api to only update a single key in the current query. E.g. when a page and search term are in the query just update the page without affecting the search term. That way abstracted components like paginations don't need to be aware of other query params.

[josevalim]

Please give the whole path for now. The reason we don't provide partial updates is because we never store all parameters. This is to avoid attacks where people would inflate LiveView sessions by sending really large payloads. So it is up to you to store the bits that you need.

[LostKobrakai]

I'm wondering how live_patch works then? It seems to do fine with just ?page=1.

[josevalim]

That's because the browser is the one doing the URL manipulation. It is the one that merges ?page=1 to the current URL.