Dynamically Tally Child Elements by Classname in Vue - vue.js

Question

I have a page that allows a user to drag/drop images into pre-defined DIVs, then I tally up the total value of the images based on their class name. What I am trying to do is get vue to read the values from each outer div.answer and get the class names of the child images.
My source code is:
<div
is="box-answers"
v-for="box in boxes.slice().reverse()"
v-bind:key="box.id"
v-bind:level="box.level"
v-bind:hint="box.hint"
></div>
<script>
Vue.component('box-answers', {
props: ['level','hint'],
template: '<div class="droppable answer :id="level" :title="hint"></div>'
});
new Vue({
el: '#mainapp',
data: {
boxes: [
{ id: 1, level: 'baselevel-1', hint: 'x 1' },
{ id: 2, level: 'baselevel-2', hint: 'x 20' },
{ id: 3, level: 'baselevel-3', hint: 'x 400' },
{ id: 4, level: 'baselevel-4', hint: 'x 8,000' },
{ id: 5, level: 'baselevel-5', hint: 'x 160,000' }
]
}
</script>
This converts to the follow HTML (the nested DIVs and SPANs are user-possible entries by dragging):
<div id="baselevel-5" class="droppable answer" title="x 160,000">
<div><img src="images/line.gif" alt="Five" class="imgfive"></div>
<span><img src="images/dot.gif" alt="One" class="imgone"></span>
</div>
...
<div id="baselevel-1" class="droppable answer" title="x 1">
<span><img src="images/line.gif" alt="One" class="imgone"></span>
</div>
Currently, I have jQuery/JavaScript calculating the point values using the following:
$(function(j) {
var arAnswers = Array(1);
count = 0; //
j("div.answer").each(function( idx ) {
currentId = j(this).attr('id');
ones = 0;
fives = 0;
if ( j("#" + currentId).children().length > 0 ) {
ones = j("#" + currentId).children().find("img.imgone").length * 1;
fives = j("#" + currentId).children().find("img.imgfive").length * 5;
arAnswers[count] = ones + fives; //Tally box value
count++;
}
});
});
I would like Vue to perform similar iteration and addition to return total value of ones and fives found based on the image classname.

Answer 1

Currently, you are approaching this problem as a pure-play DOM operation. If that is what you need then you can simply use $refs:
<!-- NOTICE ref -->
<div ref="boxAnswers"
is="box-answers"
v-for="box in boxes.slice().reverse()"
v-bind:key="box.id"
v-bind:level="box.level"
v-bind:hint="box.hint">
</div>
Inside your high-level component, you will have a function like:
function calculate() {
// NOTICE $refs
const arAnswers = this.$refs.boxAnswers.map((x) => {
// $el is the DOM element
const once = x.$el.querySelectorAll('img.imgone').length * 1;
const fives = x.$el.querySelectorAll('img.imgfive').length * 5;
return once + fives
});
return arAnswers;
}
But this is not the correct Vue way of doing things. You have to think in terms of events and data model (MVVM - don't touch DOM. DOM is just a representation of your data model). Since, you have a drag-n-drop based application, you have to listen for drag, dragstart, dragend and other drag events. For example:
<!-- NOTICE drop event -->
<div #drop="onDropEnd(box, $event)"
is="box-answers"
v-for="box in boxes.slice().reverse()"
v-bind:key="box.id"
v-bind:level="box.level"
v-bind:hint="box.hint">
</div>
Your onDropEnd event handler will look like:
function onDrop(box, $event) {
// box - on which box drop is happening
// $event.data - which image is being dropped
// Verify $event.data is actually the image you are intending
if ($event.data === 'some-type-image') {
// Do the counting manipulations here
// ... remaining code
}
}
This is not a complete code as I don't know other components. But it should help you with the required direction.