budibase/packages/materialdesign-components/src/Common/ItemStore.js

import { writable } from "svelte/store";

function createItemsStore(componentOnSelect) {
    const { subscribe, set, update } = writable([]);

    function addItem(item) {
        update(items => {
            return [...items, item]                  
        })
        if (componentOnSelect) {
            componentOnSelect();            
        }
    }

    function addSingleItem(item) {
        set([item])
        if (componentOnSelect) {
            componentOnSelect();            
        }
    }

    function removeItem(itemId) {
        update(items => {
            let index = getItemIdx(items, itemId)
            items.splice(index, 1);
            return items;
        })
        if (componentOnSelect) {
            componentOnSelect();            
        }
    }

    function clearItems() {
        set([]);
        if (componentOnSelect) {
            componentOnSelect();            
        }
    }

    function getItemIdx(items, itemId) {
        return items.findIndex(i => i._id === itemId);
    }

    return {
        subscribe,
        addItem,
        addSingleItem,
        removeItem,
        clearItems,
        getItemIdx
    }
}

export default createItemsStore