SolidJS•10mo ago

How to react to length of store array?

I have a store representing an array:

const [pools, setPools] = createStore<Pool[]>([])

const [pools, setPools] = createStore<Pool[]>([])

Elsewhere I render a list based on that array:

<Column class="px-2">
  <Row>
    <For each={pools}>{(p, i) => <PoolView index={i()} />}</For>
    <CreatePoolViewButton index={pools.length} />
  </Row>
</Column>

<Column class="px-2">
  <Row>
    <For each={pools}>{(p, i) => <PoolView index={i()} />}</For>
    <CreatePoolViewButton index={pools.length} />
  </Row>
</Column>

pools.length is always 0, even when I successfully add an element to the pool store. How do I get the value reactively?

10 Replies

deluksic•10mo ago

How did you add the element?

GhirigoroOP•10mo ago

const addPool = () => {
  setPools([...pools, { dice: 1, results: [] }])
}

const addPool = () => {
  setPools([...pools, { dice: 1, results: [] }])
}

deluksic•10mo ago

Hmm, that should work, but can you try with setPools(produce((array)=>{array.push(...)})) Or maybe CreatePoolViewButton destructures somewhere so you lose reactivity?

GhirigoroOP•10mo ago

Nope, no destructuring that I can see and:

const addPool = () => {
    // setPools([...pools, { dice: 1, results: [] }])
    setPools(
        produce(array => {
            array.push({ dice: 1, results: [] })
        })
    )
}

const addPool = () => {
    // setPools([...pools, { dice: 1, results: [] }])
    setPools(
        produce(array => {
            array.push({ dice: 1, results: [] })
        })
    )
}

has the same effect

deluksic•10mo ago

So a createEffect console.log also doesnt respond to pools.length?

GhirigoroOP•10mo ago

No it does... Here's the code for the button where I consitstently get an index value of 0:

const CreatePoolViewButton: Component<{ index: number }> = ({ index }) => {
    return (
        <button
            class="flex items-center justify-center"
            onClick={() => {
                console.log("click", index)
                // if the pool at the index is not defined, add a new pool
                if (pools[index] === undefined) addPool()
                else removePool(index)
            }}
        >
            <svg
                class="w-4 h-4 text-light stroke-light"
                viewBox="0 0 24 24"
                fill="none"
                stroke="currentColor"
                stroke-width="1"
                stroke-linecap="round"
                stroke-linejoin="round"
            >
                <circle cx="12" cy="12" r="11"></circle>
                <line
                    style={{
                        transition: "transform 0.3s",
                        "transform-origin": "center",
                        transform: `rotateZ(${pools[index] !== undefined ? "90" : "0"}deg)`,
                    }}
                    x1="12"
                    y1="8"
                    x2="12"
                    y2="16"
                ></line>
                <line x1="8" y1="12" x2="16" y2="12"></line>
            </svg>
        </button>
    )
}

const CreatePoolViewButton: Component<{ index: number }> = ({ index }) => {
    return (
        <button
            class="flex items-center justify-center"
            onClick={() => {
                console.log("click", index)
                // if the pool at the index is not defined, add a new pool
                if (pools[index] === undefined) addPool()
                else removePool(index)
            }}
        >
            <svg
                class="w-4 h-4 text-light stroke-light"
                viewBox="0 0 24 24"
                fill="none"
                stroke="currentColor"
                stroke-width="1"
                stroke-linecap="round"
                stroke-linejoin="round"
            >
                <circle cx="12" cy="12" r="11"></circle>
                <line
                    style={{
                        transition: "transform 0.3s",
                        "transform-origin": "center",
                        transform: `rotateZ(${pools[index] !== undefined ? "90" : "0"}deg)`,
                    }}
                    x1="12"
                    y1="8"
                    x2="12"
                    y2="16"
                ></line>
                <line x1="8" y1="12" x2="16" y2="12"></line>
            </svg>
        </button>
    )
}

If I add this at the top of the button component:

createEffect(() => {
  console.log("index", index)
})

createEffect(() => {
  console.log("index", index)
})

it always comes out 0

deluksic•10mo ago

Yeah, you destruct props which is a no no

GhirigoroOP•10mo ago

Oh crap! So sorry

deluksic•10mo ago

No worries, you can look into eslint plugin to help catch these

GhirigoroOP•10mo ago

It's just so ingrained in me I literally don't see it any more when it's in the function parameters Thanks for your help and sorry to waste your time

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How to react to length of store array?