Access vue components created via v-for from an array of objects

Question

I have the following template and I want to call a method of the dynamically created components in the v-for statement.

For example I want to call on each row the row.getSubtotal() method. I do not know how to do it as this.rows returns the original array and not the array of components.

 <template>
    <div>
        <table class="table table-bordered">
            <thead>
                <th  v-for="c in columns" v-bind:class="[c.className ? c.className : '']" :key="c.code">{{c.label}}</th>
            </thead>
            <tbody>
            <row v-for="(row, index) in rows"
                 :index="index+1"
                 :init-data="row"
                 :columns="columns"
                 :key="row.hash"
                 :hash="row.hash"
                 v-on:remove="removeRow(index)"></row>
            </tbody>
        </table>
        <div class="d-flex">
            <table>
                <tr>
                    <td>Unique SKUs:</td>
                    <td>{{rows.length}}</td>
                    <td>Total units:</td>
                    <td>{{totalUnits}}</td>
                </tr>
            </table>
            <span class="flex-fill"></span>
            <button class="btn" @click="newRow">Nueva línea</button>
        </div>
    </div>
</template>

The <row> element is a Vue component that it's created via the rows property that contains an array of objects with each rows property. For example:

...
import Row from './Row'

export default {
    name: "OrderTable",
    components: {Row},
    data: () => ({
        hashes: [],
        rows: [
           {hash: '_yug7', sku: '85945', name: 'Coconut butter', price: 20},
           {hash: '_g484h', sku: '85745', name: 'Coconut oil', price: 15},
           {hash: '_yug7', sku: '85945', name: 'Cramberry juice', price: 5},
        ],
        fixedColumns: [
            {code: 'index', label: '#'},
            {code: 'sku', label: 'SKU'},
            {code: 'name', label: 'Product name', className: 'text-left align-middle'},
            {code: 'quantity', label: 'Units'},
            {code: 'price', label: 'Price', className: 'text-right align-middle'}
        ]
    }),
    computed: {
        totalUnits: function () {
            for(let x in this.rows) {
                // HERE I WANT TO CALL A METHOD IN THE ROW COMPONENT
                // For example this.rows[x].getSubtotal()
            }
        }
    },
...

Answer 1

Consider v-for and v-model combination to export all the data you need from your row children. Your <row /> will need to implement the v-model interface so look it up.

Of course you could use actions $emit(),$on(), etc. and make rows signal the parent component their states everytime they need to.

Hope this points you to the right direction.

Answer 2

Dynamically create a ref attribute on each component and call it afterwards:

<template>
    <div>
        <table class="table table-bordered">
            <thead>
                <th  v-for="c in columns" v-bind:class="[c.className ? c.className : '']" :key="c.code">{{c.label}}</th>
            </thead>
            <tbody>
            
            <!-- Add the ref attribute to each row -->
            <row v-for="(row, index) in rows"
                 :ref="`myRow${index}`"
                 :index="index+1"
                 :init-data="row"
                 :columns="columns"
                 :key="row.hash"
                 :hash="row.hash"
                 v-on:remove="removeRow(index)"></row>

            </tbody>
        </table>
        <div class="d-flex">
            <table>
                <tr>
                    <td>Unique SKUs:</td>
                    <td>{{rows.length}}</td>
                    <td>Total units:</td>
                    <td>{{totalUnits}}</td>
                </tr>
            </table>
            <span class="flex-fill"></span>
            <button class="btn" @click="newRow">Nueva línea</button>
        </div>
    </div>
</template>

To call a method on the component, do this:

computed: {
        totalUnits: function () {
            for(let (x, index) in this.rows) {
                let row = this.$refs[`myRow${index}`]
                // You now have an instance of the component
                let subtotal = row.getSubtotal()
            }
        }
    },

More information for the $refs attribute here: what's the real purpose of 'ref' attribute?