Feature Request: Excluded props

[Martin Mochetti]

It would be ideal to tell inertia rails that when a partial load is done (e.g only: ["some_prop"]) only that prop is computed. In order to do this, we need an auxiliary method that allows us to skip props on partial loads.

For example, if we have:

inertia_share do
  {
    heavy_prop: SomethingHeavyToCompute.get,
    notifications: NotificationsSerializer.one(current_user)
  }
end

And then in the frontend we do:

router.reload({ only: ["notifications"] })

heavy_prop is not rendered, but it is computed. This is not ideal when we want to work with partial loads.

The only way I can think this can be achieved is by making heavy props excluded on partial loads:

inertia_share do
  {
    heavy_prop: InertiaRails.on_full_load(-> { SomethingHeavyToCompute.get }),
    notifications: NotificationsSerializer.one(current_user)
  }
end

Is this something appealing for anyone else? If so, I can work on it and send a PR.

[Martin Mochetti]

Found out that we can use heavy_prop: -> { SomethingHeavyToCompute.get } to achieve this. Closing.

[Brian Knoles]

Hey @mochetts ! You are correct that inertia-rails supports this feature. Inertia.js calls it partial reloads: https://inertiajs.com/partial-reloads

A few additional nuances:

1. If you want to exclude heavy_prop on the initial page load, you'll need to wrap the lambda like so:

InertiaRails.lazy(->() { # won't run on initial page load })

2. If you want to exclude the other props from running in the partial reload, you'll need to wrap them a lambda. Consider this example:

inertia_share do
  {
    heavy_prop_1: FirstHeavyThing.run,
    heavy_prop_2: InertiaRails.lazy(->() { SecondHeavyThing.run }),
  }
end

Even if you only grab heavy_prop_2 on a partial reload, FirstHeavyThing.run will still run. InertiaRails just won't pass the result back to the frontend. To prevent it from running on every page load, this will work:

inertia_share do
  {
    heavy_prop_1: ->() { FirstHeavyThing.run }, # now this won't run on partial reloads that don't ask for it
    heavy_prop_2: InertiaRails.lazy(->() { SecondHeavyThing.run }),
  }
end