feat: expose remote function query data to a global variable

[jdgamble555]

Describe the problem

In Classic SvelteKit, you can get all page data anywhere in your app through the page variable (previously $page). This is specifically available under page.data for data that is returned.

You cannot do this with a Remote Function query(). The data is NOT available globally, although it can be cached in multiple components.

Imagine this scenario:

• Layout (Breadcrumb) - no await
  • Users (await getUserList())
    • Jonathan (await getUser())
  • Posts (await getPostList())
    • My Post 1 (await getPostById(params.id))
      • Comment 2 (await getCommentById(params.comment_id))
  • About -- no await

And I want to display a simple breadcrumb:

Home -> Users -> Jonathan
Home -> Posts -> SvelteKit Remote Functions Tips
Home -> About

I can set the Breadcrumbs in the +layout.svelte file, BUT I am actually querying the data on the page itself... (username, page title, comment title, or no query at all, etc)

This CAN be solved using +page.server.ts for the query, and setting the crumb data in the +layout.svelte with page.data.

However, this is impossible to work using Remote Function queries.

Describe the proposed solution

Either:

1. Expose the query data globally in page.query... like page.query.myFunc...
2. Expose the query data globally in query or query.data... like query.myFunc...

Alternatives considered

1. Use +page.server.ts instead of query() to set the data using page.data... this can mess up your query refreshes etc, since it DOES NOT use query() and has you revert back to old paradigms.
2. Use hooks.server.ts to replace your entire HTML with something like %crumbs% that you query in query() and set like event.locals.query... etc... basically just hack the HTML right before render.

Importance

would make my life easier

Additional Information

Basically I can't use Remote Functions without it, since I have shared data in a layout.

[jjones315]

I can’t think of good ergonomic for this since the keys of remote functions are hashed you would basically have to call/know the function in the layout.

Not to you don’t need X you need Y, but well I guess I’m going to.

In the past I’ve used portals to solve this. So the page renders the breadcrumb.

[jdgamble555]

I don't know what portals are. I assume you mean layouts, but then you can't use query().

But that is a good point that you would have to know the function name, so then it should probably work like page.data... it combines ALL current function data into query.data or something similar...

I'm also open to ways to solve the problem using Remote Functions...

J

[jjones315]

A portal lets you render content into a different part of the DOM.

In your +layout.svelte you would have.

<div id=“breadcrumb-outlet”></div>

Then in you +page.svelte you would have

<Portal to=“#breadcrumb-outlet”>
    This content will render in your layout where ever you place the outlet. 
</Portal>

Right now svelte doesn’t have native portal support (I know there is a branch floating around)

But you can use bits-ui or just copy the source in you app, it’s quite small less than 100 lines if I recall.

Here are the react docs for the equivalent feature
https://react.dev/reference/react-dom/createPortal

[jdgamble555]

@jjones315 - This is not what I'm asking. Sure, you can use some new HTML feature or even refresh the layout with JavaScript, but it needs to be possible to render the data in another component like you can with page.data...

This is an HTML workaround, and has nothing to do with SvelteKit or server rendering.

J

[jjones315]

I understand this isn’t the answer to your question, just another solution to the problem you presented. Didn’t want to get caught in the xy problem.

My gut tells my exposing all remote queries like that is an anti pattern since I don’t know how you would key it reliably. You could have 2 functions with the same name from files, and the parameters are encoded. You would basically need to call the function.

[AbdulHadi-Mughal]

@jjones315 - This is not what I'm asking. Sure, you can use some new HTML feature or even refresh the layout with JavaScript, but it needs to be possible to render the data in another component like you can with page.data...

The Sveltekit standard seems to be just calling the remote functions in +layout.svelte as well. As it will point to the same cache, it is mostly identical to a globally accessible variable like inside page.data.

And that may mean that +layout.svelte now has to juggle between different functions depending on routes, but the same conditional branching would also appear in global page.data values, where you have to check results of different functions (e.g page.data.func1 or page.data.func2) depending on routes.

(I am not into Sveltekit internals so may be wrong in some details)

[jdgamble555]

@AbdulHadi-Mughal - Yes and No.
I actually prefer merging the data to query.data instead of query.data.funcName just like page.data, but filtering wouldn't be so terrible if that were the only option.

Imagine having a global +layout.svelte function where you get the data:

export const globalQuery = query(() => {

  const { params } = getRequestEvent();

  const id = params.id;

  // determine what database query to call
  // users / posts / comments / bookmarks ?

});

Problem 1

I can't exactly pass the params.id, since it may be params.user_id or params.slug etc. And we know it gets cached by parameters for dedup, so not a good idea NOT to pass it.

Problem 2

Using a conditional to find data in an object is not the same thing as using a conditional to await and fetch data.

const crumb = $derived(page.data.crumb);

That's all I currently have to do with +layout.svelte, but you could just as easily do:

const crumb = $derived(query.data
	.map((item) => item.crumb)
	.filter((value): value is string => Boolean(value)));
// or whatever ts function here, much easier than trying to filter a global fetch function

J