How to let one component correspond with the other for a specific function - html

Question

I've got a component where I click a color of a machine, when I change colors, the machine gets loaded with a different color inside a image carousel.
Now I also created a component in the bottom with a image gallery of the same machine. How can I make it that the image gallery also changes color when I click the color button in the top of the page?
Important notice: The two components are not in the same parent component but they do load in the same machine images already, so the methods are not wrong I believe.
this is the clickable color button:
<li
v-for="(color, index) in machine.content[0].machine_colors"
:key="color.color_slug"
v-if="color.inStock"
v-on:click="selectColor(index)"
v-bind:class="{ active: (color.color_slug === selectedColor.color_slug)}">
<img v-bind:src="color.color_dash">
</li>
this is the component that changes color:
<div class="product__carousel">
<Carousel showIcon v-if="selectedColor" :machineColor="selectedColor"/> <!-- Image carousel gets loaded in -->
</div>
and the component that needs to change color but does not:
<div id="tab-two-panel" class="panel">
<footerGallery v-if="selectedColor && machine" :machineColor="selectedColor"/>
</div>
Heres the script of the partent component:
export default {
name: 'aboutMachine',
components: {
Collapse,
footerGallery,
},
data() {
return{
selectedColor: this.getMachineColorContent(),
}
},
props: {
main: {
default () {
return {};
},
},
machine: {
default () {
return {};
},
},
},
methods: {
getMachineColorContent() {
if (this.selectedColor) {
return null;
}
return this.machine.content[0].machine_colors[0];
},
selectColor(index) {
this.selectedColor = this.machine.content[0].machine_colors[index];
},
},
}
and the component itself:
export default {
name: 'footerGallery',
props: {
showIcon: Boolean,
machineColor: {
default () {
return {};
},
},
},
data() {
return {
highLightedThumbIndex: 0,
isActive: undefined,
};
},
created() {
this.highLightedThumbIndex = this.highLightedThumbIndex || 0;
},
methods: {
selectThumb(index) {
this.highLightedThumbIndex = index;
},
},
};
This is my main.js
import Vue from 'vue';
import VueYouTubeEmbed from 'vue-youtube-embed'
import FontAwesome from './libs/fa';
import App from './App';
const eventHub = new Vue();
Vue.use(VueYouTubeEmbed);
Vue.component('font-awesome-icon', FontAwesome);
Vue.config.productionTip = false;
/* eslint-disable no-new */
new Vue({
el: '#app',
components: { App },
template: '<App/>',
});

Answer 1

I would use events to accomplish this. The migration guide to Vue2 has a good short explanation of how to do simple event routing without using a full Vuex solution. In your case, you would declare a global event hub in one of your js files:
var eventHub = new Vue();
In your selectColor method you would emit the index selected:
selectColor(index) {
this.selectedColor = this.machine.content[0].machine_colors[index];
eventHub.$emit("select-color",index);
}
And in the footer, you would register a listener for the select-color event that calls selectThumb with the payload of the event (which is the selected index):
created() {
this.highLightedThumbIndex = this.highLightedThumbIndex || 0;
eventHub.$on("select-color",this.selectThumb);
}