SolidJS•5mo ago

My first solid component

Just wrote my first component. I only wrote React before so I wanted to know if there are better ways to do things than what I figured out so far :)

import { createBreakpoints } from "@solid-primitives/media";
import { children, For, mergeProps } from "solid-js";

import type { JSX, ParentComponent } from "solid-js";

interface ColumnsProps extends JSX.HTMLAttributes<HTMLDivElement> {
  columns?: number | Record<number, string>;
}

export const Columns: ParentComponent<ColumnsProps> = (props) => {
  const merged = mergeProps({ columns: 3 }, props);

  return (
    <div {...merged}>
      <For
        each={getColumnArray({
          children: children(() => merged.children).toArray(),
          columnAmount:
            typeof merged.columns === "object"
              ? Object.entries(createBreakpoints(merged.columns)).reduce(
                  (acc, [key, value]) => (value ? Number(key) : acc),
                  1,
                )
              : merged.columns,
        })}
      >
        {(column) => <div>{column}</div>}
      </For>
    </div>
  );
};

interface GetColumnArray {
  children: JSX.Element[];
  columnAmount: number;
}

const getColumnArray = ({ children, columnAmount }: GetColumnArray) =>
  children.reduce(
    (acc: JSX.Element[][], child, index) => (acc[index % columnAmount]?.push(child), acc),
    Array.from({ length: columnAmount }, () => []),
  );

import { createBreakpoints } from "@solid-primitives/media";
import { children, For, mergeProps } from "solid-js";

import type { JSX, ParentComponent } from "solid-js";

interface ColumnsProps extends JSX.HTMLAttributes<HTMLDivElement> {
  columns?: number | Record<number, string>;
}

export const Columns: ParentComponent<ColumnsProps> = (props) => {
  const merged = mergeProps({ columns: 3 }, props);

  return (
    <div {...merged}>
      <For
        each={getColumnArray({
          children: children(() => merged.children).toArray(),
          columnAmount:
            typeof merged.columns === "object"
              ? Object.entries(createBreakpoints(merged.columns)).reduce(
                  (acc, [key, value]) => (value ? Number(key) : acc),
                  1,
                )
              : merged.columns,
        })}
      >
        {(column) => <div>{column}</div>}
      </For>
    </div>
  );
};

interface GetColumnArray {
  children: JSX.Element[];
  columnAmount: number;
}

const getColumnArray = ({ children, columnAmount }: GetColumnArray) =>
  children.reduce(
    (acc: JSX.Element[][], child, index) => (acc[index % columnAmount]?.push(child), acc),
    Array.from({ length: columnAmount }, () => []),
  );

22 Replies

t•5mo ago

Code and image are the same, I attached it because I find Discord's codeblocks hard to read

bigmistqke•5mo ago

1. What is the use of the .toArray() with the children? 2. children(...) returns a signal containing the resolved children. To get the actual children you would need to call it. 3. Something to look out for: props.children can either be a single element or an array of elements.

t•5mo ago

1. that's the solution I found for iterating over children

t•5mo ago

merged.children is of type JSX.Element | undefined so I can't iterate over it props.children is of the same type so I think 2. is wrong

bigmistqke•5mo ago

interesting! that stackoverflow example will not be reactive but in your case it will work fine, since you are calling children() inside the JSX

bigmistqke•5mo ago

did not know about toArray!

bigmistqke•5mo ago

but this would be reactive:

function Stuff(){
  const cs = children(() => props.children).toArray
  return <For each={cs()}>...</For>
}

function Stuff(){
  const cs = children(() => props.children).toArray
  return <For each={cs()}>...</For>
}

cool!

thetarnav•5mo ago

calling children in jsx will be reactive but it will also wastefully recreate memos each time it reruns so better to go with what @bigmistqke wrote also it currently has an issue that if collumns prop changes, props.children will be executed again, recreating elements

t•5mo ago

I think it's reactive already?

t•5mo ago

At least this works Unless I'm misunderstanding

t•5mo ago

This seems to be working fine too even though I'm getting a warning @ line 22

This function should be passed to a tracked scope (like createEffect) or an event handler because it contains reactivity, or else changes will be ignored.

I can't tell whether this is a false positive or something is actually wrong and I don't understand it @joshwilsonvu can you help?

bigmistqke•5mo ago

but it will also wastefully recreate memos each time it reruns

you are still creating a memo each time. better to bring children() outside of getColumns and into ColumnsProps body like

const Columns = (props) => {
   const childs = childen(() => props.children).toArray;
   const getColumns = () => childs.reduce(...)

const Columns = (props) => {
   const childs = childen(() => props.children).toArray;
   const getColumns = () => childs.reduce(...)

bigmistqke•5mo ago

This function should be passed to a tracked scope (like createEffect) or an event handler because it contains reactivity, or else changes will be ignored.

this might be solved by renaming getColumns to createColumns see https://github.com/solidjs-community/eslint-plugin-solid/issues/112#issuecomment-1844195070

GitHub

Enable customizing reactive rule to treat certain custom functions ...

Describe the need I am making a library for my team which handles data fetching with our custom protocol. The library will take in the arguments to the API call and return a signal, very similar to...

thetarnav•5mo ago

generally if something starts with create or use or returns an accessor instead of the value, you probably want to use it at high as possible (eg in component body, parent component or global store), instead of inlining it in jsx, memos, or functions like getColumns. also even if stuff is updating correctly on the screen you might want to add random console logs to various places to see if something isn't updating more then it should in solid functions should rerun only when needed, no more no less eg elements are good to check if they are not recreated for some reason, because that might be expensive and cause weird behaviors later, even though it seems ok because "it's reactive" <div ref={console.log} /> <- will log every time an element is created

t•5mo ago

Childs isn't getting called here so you can't reduce it That didn't work I don't think I understand how memos work How do I check if one is being created

bigmistqke•5mo ago

oops typo, u right. should be

const Columns = (props) => {
   const childs = childen(() => props.children).toArray;
   const getColumns = () => childs().reduce(...)

const Columns = (props) => {
   const childs = childen(() => props.children).toArray;
   const getColumns = () => childs().reduce(...)

it's mentioned in the docs https://www.solidjs.com/docs/latest/api#children

The return value is a memo evaluating to the resolved children, which updates whenever the children change.

with a memo we mean createMemo: https://www.solidjs.com/docs/latest/api#creatememo . you can think of it as a combination of a createEffect and createSignal: a signal that only updates whenever one of its dependencies change.

t•5mo ago

Oh that makes sense As for this I think I'll just disable eslint for that line

bigmistqke•5mo ago

ye the linter is quite aggressive.. i never use it in my own code tbh can u post the code? wanna check it in the playground

t•5mo ago

import { createBreakpoints } from "@solid-primitives/media";
import { children, For, mergeProps } from "solid-js";

import type { JSX, ParentComponent } from "solid-js";

interface ColumnsProps extends JSX.HTMLAttributes<HTMLDivElement> {
  columns?: number | Record<number, string>;
}

export const Columns: ParentComponent<ColumnsProps> = (_props) => {
  const props = mergeProps({ columns: 3 }, _props);

  const columnAmount = () =>
    typeof props.columns === "object"
      ? Object.entries(createBreakpoints(props.columns)).reduce((acc, [key, value]) => (value ? Number(key) : acc), 1)
      : props.columns;

  const resolved = children(() => props.children).toArray;

  const createColumns = () =>
    resolved().reduce(
      // eslint-disable-next-line solid/reactivity
      (acc: JSX.Element[][], child, index) => (acc[index % columnAmount()]?.push(child), acc),
      Array.from({ length: columnAmount() }, () => []),
    );

  return (
    <div ref={console.log} {...props}>
      <For each={createColumns()}>{(column) => <div>{column}</div>}</For>
    </div>
  );
};

import { createBreakpoints } from "@solid-primitives/media";
import { children, For, mergeProps } from "solid-js";

import type { JSX, ParentComponent } from "solid-js";

interface ColumnsProps extends JSX.HTMLAttributes<HTMLDivElement> {
  columns?: number | Record<number, string>;
}

export const Columns: ParentComponent<ColumnsProps> = (_props) => {
  const props = mergeProps({ columns: 3 }, _props);

  const columnAmount = () =>
    typeof props.columns === "object"
      ? Object.entries(createBreakpoints(props.columns)).reduce((acc, [key, value]) => (value ? Number(key) : acc), 1)
      : props.columns;

  const resolved = children(() => props.children).toArray;

  const createColumns = () =>
    resolved().reduce(
      // eslint-disable-next-line solid/reactivity
      (acc: JSX.Element[][], child, index) => (acc[index % columnAmount()]?.push(child), acc),
      Array.from({ length: columnAmount() }, () => []),
    );

  return (
    <div ref={console.log} {...props}>
      <For each={createColumns()}>{(column) => <div>{column}</div>}</For>
    </div>
  );
};

bigmistqke•5mo ago

thanks 🙏 i feel that the linter should be able to recognise these situations.

createEffect(() => {
  resolved().reduce(
    (acc: JSX.Element[][], child, index) => {
      acc[index % columnAmount()]?.push(child);
      return acc;
    },
    Array.from({ length: columnAmount() }, () => []),
  );
});

createEffect(() => {
  resolved().reduce(
    (acc: JSX.Element[][], child, index) => {
      acc[index % columnAmount()]?.push(child);
      return acc;
    },
    Array.from({ length: columnAmount() }, () => []),
  );
});

gives the same linter-error

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My first solid component