Feasibility: Composite UI
- Is it possible to create a composite UI (micro front end) based on vue by using standard vue tools?
Yes, it is possible. Pretty much any independent Vue-component you see published around (vue-select, vue-slider-component and even full "sets" of components such as vuetify, bootstrap-vue or vue-material are examples of reusable (composable) components developed using standard Vue tools.
Page transistions: Routing
- We have more than one page, so we need a solution to navigate from one side to another. How can we realize page transitions?
vue-router is the tool for this job. It is developed by the core team, so expect tight integration and great feature support.
Event-Bus
- Is it possible to established a Event-Bus between the VueJS components?
Every Vue instance implements an events interface. This means that to communicate between two Vue instances or components you can use Custom Events. You can also use Vuex (see below).
Bidirectional communication
- How can we implement a bidirectional communication between the components?
The best way to send data from parent component to child is using props.
Steps:
- Declare
props (array or object) in the child
- Pass it to the child via
<child :name="variableOnParent">.
See demo below:
Vue.component('child-comp', {
props: ['message'], // declare the props
template: '<p>At child-comp, using props in the template: {{ message }}</p>',
mounted: function () {
console.log('The props are also available in JS:', this.message);
}
})
new Vue({
el: '#app',
data: {
variableAtParent: 'DATA FROM PARENT!'
}
})
<script src="https://unpkg.com/vue@2.5.13/dist/vue.min.js"></script>
<div id="app">
<p>At Parent: {{ variableAtParent }}</p>
<child-comp :message="variableAtParent"></child-comp>
</div>
You can also get references for Child Components (refs) and call methods on them.
Vue.component('my-comp', {
template: "#my-comp-template",
props: ['name'],
methods: {
saveMyComp() {
console.log('Saved:', this.name);
}
}
})
new Vue({
el: '#app',
data: {
people: [{name: 'Bob'}, {name: 'Nelson'}, {name: 'Zed'}]
},
methods: {
saveChild(index) {
this.$refs.myComps[index].saveMyComp();
}
}
});
<script src="https://unpkg.com/vue@2.5.13/dist/vue.min.js"></script>
<div id="app">
<div v-for="(person, index) in people">
<button @click="saveChild(index)">saveMyComp</button>
<my-comp :name="person.name" ref="myComps"></my-comp>
</div>
</div>
<template id="my-comp-template">
<span> {{ name }} </span>
</template>
To communicate from child to parent, you'll use events. See demo below. There are also several modifiers that make this task easier.
var parent = {
template: '<div><child :content.sync="localContent"></child><br>At parent: {{ localContent }}</div>',
props: ['content'],
data() {
return {
localContent: this.content
}
}
};
var child = {
template: '<div>At child: {{ content.value }}<button @click="change">change me</button></div>',
props: ['content'],
methods: {
change() {
this.$emit('update:content', {value: "Value changed !"})
}
}
};
Vue.component('child', child);
Vue.component('parent', parent);
new Vue({
el: '#app'
});
<script src="https://unpkg.com/vue@2.5.13/dist/vue.js"></script>
<div id="app">
<parent :content="{value:'hello parent'}"></parent>
</div>
Vuex
Inevitably, though, as your application grows, you will have to use a more scalable approach. Vuex is the de facto solution in this case. Roughly, when using Vuex, you won't have to pass state around from parent to child: all of them will pick it up from the Vuex store (sort of a "global" reactive variable). This greatly simplifies the application management and is worth a post of its own.
Final note: As you can see, one great advantage of Vue is how easy you can prototype and test functionality. No build step, few abstractions over raw JS. Compared to other frameworks, I'd say this is an important bonus.
