classy-store

class stores for svelte.

Usage

npm i classy-store

# yarn add classy-store

You must enable experimentalDecorators in your tsconfig to use the @mutator decorator.

Define a store

import { mutator, Store } from "classy-store";
export class Spike extends Store<Spike> {
    name: string;
    count: number;
    constructor(name: string, count?: number) {
        super();
        this.name = name;
        this.count = count ?? 0;
    }
    @mutator
    inc(n = 1) {
        this.count = this.count + n;
        return this.count;
    }

    @mutator
    async delayed() {
        await new Promise((res) => setTimeout(res, 500));
        this.count + 100;
    }
}

Use the store

<script lang="ts">
    import { Spike } from '$lib/spike';
    let spike = new Spike('this is a store');
</script>

<h1>Hello {$spike.name}</h1>

<h2>Bindings</h2>
<input bind:value={$spike.name} />

<h3>Using @mutator allows for methods:</h3>
<button on:click={() => $spike.inc()}>{$spike.count}</button>

<h3>methods can be promises:</h3>
<button on:click={() => { $spike.delayed(); }}>level up</button>

@mutator

@mutator is a wrapper around your method which executes store.broadcast after your method is finished altering the store's state.

• If your method returns a Promise, broadcast is called immediately and again when the promise is resolved or rejected.
• If a Promise is returned, executing[methodName] is set to Execution.Running.
• If the Promise resolves successfully, executing[methodName] is set to Execution.Resolved.
• If the Promise is rejected, executing[methodName] is set to Execution.Rejected
• If the Promise is rejected, an "error" event is emitted with the reason.

<script lang="ts">
    import { Spike } from '$lib/spike';
    import { Execution } from 'classy-store'
    let spike = new Spike('this is a store');
    let disabled = false
    $: disabled = $spike.executing.delayed === Execution.Running
</script>
<button on:click={spike.delayed()} {disabled || undefined}>{$spike.count}</button>

errors

The default error handler stores _errors in a queue on your store. The max size a configurable by setting maxErrorsToStore on Options passed to the Store constructor.

Derived stores

The stores can be derived:

<script lang="ts">
    import { Spike } from "$lib/spike";
    import { derived } from "svelte/store";
    let spike = new Spike("this is a store");
    const screaming = derived(spike, ($spike) => $spike.name.toUpperCase());
</script>
<h1>hello {$screaming}</h1>

<input bind:value="{$spike.name}" />

Custom Events

The stores are event emitters although more work is needed on that front.

If you wish to emit custom events, type your store such as:

interface MyEvents {
    example: (value: string) => void;
}

class Spike extends Store<Spike, MyEvents> {
    constructor() {
        super();
        this.emit("example", "example should be typed");
    }
}

Partial updates

You can update the store with a new instance or a partial of the fields:

<script lang="ts">
    import { Spike } from "$lib/spike";
    let spike = new Spike("this is a store");
</script>

<h1>Hello {$spike.name}</h1>
<button on:click={()=> { $spike.set({name:"..."})}}>

Notes

Please feel free to create an issue for any question, feedback or bug you encounter.

Example REPL

A very simple javascript REPL is available here.

Dependencies

• typed-emitter
• events

TODO:

• better name
• tests
• better docs

License

MIT