The props are reactive, right?

I've created a small wrapper around solid-table:

export function DataTable<TData extends { id: string }>(props: {
  data: TableOptions<TData>["data"];
  columns: TableOptions<TData>["columns"];
}) {
  // const [data, setData] = createSignal(props.data);
  const table = createSolidTable({
    data: props.data,
    // data: data(),
    columns: props.columns,
    getCoreRowModel: getCoreRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getRowId: (row) => row.id,
  });

  createEffect(() => console.log(props.data));
  
  // createEffect(() => setData(props.data));
  // createEffect(() => console.log(data()));

export function DataTable<TData extends { id: string }>(props: {
  data: TableOptions<TData>["data"];
  columns: TableOptions<TData>["columns"];
}) {
  // const [data, setData] = createSignal(props.data);
  const table = createSolidTable({
    data: props.data,
    // data: data(),
    columns: props.columns,
    getCoreRowModel: getCoreRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getRowId: (row) => row.id,
  });

  createEffect(() => console.log(props.data));
  
  // createEffect(() => setData(props.data));
  // createEffect(() => console.log(data()));

I use this component within a Suspense. Therefore props.data is equal to [], then populated with data. However, it doesn't seem to trigger an update. I tried to use a signal in the middle to make it reactive (see the comments) even if props.data is already reactive. The effects are triggered and logging the data, but the table remains empty 🤔

10 Replies

Brendonovich•9mo ago

props are reactive, but you're reading them once in the component body and then that's it. you'll want to do something like this instead

export function DataTable<TData extends { id: string }>(props: {
  data: TableOptions<TData>["data"];
  columns: TableOptions<TData>["columns"];
}) {
  // const [data, setData] = createSignal(props.data);
  const table = createSolidTable({
    get data() {
      return props.data
    },
    get columns() {
      return props.columns
    },
    getCoreRowModel: getCoreRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getRowId: (row) => row.id,
  });

export function DataTable<TData extends { id: string }>(props: {
  data: TableOptions<TData>["data"];
  columns: TableOptions<TData>["columns"];
}) {
  // const [data, setData] = createSignal(props.data);
  const table = createSolidTable({
    get data() {
      return props.data
    },
    get columns() {
      return props.columns
    },
    getCoreRowModel: getCoreRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getRowId: (row) => row.id,
  });

binajmenOP•9mo ago

Ow, works like a charm. What should I read to better understand this paradigm? I feel I missed a step in my understanding of theses cases in the Solid world Is it common to use this "trick"?

Brendonovich•9mo ago

not sure where else to read about it, but yeah it's pretty common props are (usually) getters and components only run once so reactivity needs to be triggered through function calls or accessing getters

binajmenOP•9mo ago

I'll definitely keep that in mind thank you 🙏

bigmistqke•9mo ago

imo this video is great to get an intuition behind the why https://www.youtube.com/watch?v=cELFZQAMdhQ

SolidJS

YouTube

Intro to SolidJS reactivity (in 5 minutes)

An introduction video that walks you through Solid's reactivity in under 5 minutes.

Birk Skyum•9mo ago

The guides in docs.solidjs.com are a good intro as well

binajmenOP•9mo ago

Yeah I thought I understood all the finesse of Solid while observing and not using. Now that I'm using it actively. I guess I was wrong 😅 I went through the video and this guide: https://docs.solidjs.com/advanced-concepts/fine-grained-reactivity Still, it is unclear for me how the getter trick is working in my case how passing the data via a getter function make it reactive?

    data: props.data,

    vs.

    get data() {
      return props.data
    },

    data: props.data,

    vs.

    get data() {
      return props.data
    },

does the getter function magically subscribe itself to the signal behing props.data?

bigmistqke•9mo ago

Props is an object that has getters for its dynamic properties:

<Component prop={signal()}/>

<Component prop={signal()}/>

becomes after transpilation something like

Component({ get prop(){ return signal() } })

Component({ get prop(){ return signal() } })

When inside Component you access the prop it will call this signal.

const value = props.prop

const value = props.prop

you can think of as

const value = signal()

const value = signal()

If you access a signal outside of an effect it will not be reactive (because there is no effect to be re-run) That's why

const table = createSolidTable({
  data: props.data,
  columns: props.columns,
  getCoreRowModel: getCoreRowModel(),
  getSortedRowModel: getSortedRowModel(),
  getRowId: (row) => row.id,
});

const table = createSolidTable({
  data: props.data,
  columns: props.columns,
  getCoreRowModel: getCoreRowModel(),
  getSortedRowModel: getSortedRowModel(),
  getRowId: (row) => row.id,
});

is not reactive as all the signals hidden behind the props are called during initialisation. While with

const table = createSolidTable({
  get data() {
    return props.data
  },
  get columns() {
    return props.columns
  },
  ...
});

const table = createSolidTable({
  get data() {
    return props.data
  },
  get columns() {
    return props.columns
  },
  ...
});

we are not accessing/calling the signals during initialisation, but instead passing them straight to createSolidTable.

bigmistqke•9mo ago

a very simple playground to explain the main idea: https://playground.solidjs.com/anonymous/3d44bce0-fa6f-4c48-bc0b-5920a3d14977

Solid Playground

Quickly discover what the solid compiler will generate from your JSX template

binajmenOP•9mo ago

thank you, very clear

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Programming

The props are reactive, right?