How to control the flow of vue application - vue.js

I'm trying to make a game using vue and I designed the following structure:
<template>
<div v-if="status==='beforegamestart'" key="beforegamestart">
<button v-on:click="startGame()">Start</button>
</div>
<div v-else-if="status==='inprocess'" key="inprocess">
<h1>Game in process</h1>
<button v-on:click="finishGame()">Finish</button>
</div>
<div v-else-if="status==='gameover'" key="gameover">
<h2>Game over</h2>
</div>
<div v-else>
<h1>Else</h1>
</div>
</template>
<script>
export default {
name: 'GameComponent',
data() {
return {
status: 'beforegamestart'
}
},
methods: {
startGame: function() {
this.status = "inprocess";
},
finishGame: function() {
this.status = "gameover";
}
}
}
</script>
<style>
</style>
I wonder what is the common way to make a game like flappy bird in vue, which has a start menu, game in process, and a finish view? Is it OK to do it in this way? I just wonder how to change different views properly.

If I was was you, I'd do the following:
Step 1: Split the start, in-progress, and game-over screens into their own components. and import them into App.vue(or whatever you want) like so:
import Start from './Start.vue'
import Game from './Game.vue'
import GameOver from './GameOver.vue'
Step 2: Use a dynamic component in the template. See https://v2.vuejs.org/v2/guide/components.html#Dynamic-Components
<component :is="currentState"/>
Step 3: Have a method/computed property(or for bonus points, use vuex) that handles the current state of the game and have to components render based on that value.
computed: {
currentState: function() {
switch(status){
case "beforeGameStart":
return "Start";
break;
...
}
}
}

Related

Async loading child component doesn't trigger v-if

Hi everyone and sorry for the title, I'm not really sure of how to describe my problem. If you have a better title feel free to edit !
A little bit of context
I'm working on a little personal project to help me learn headless & micro-services. So I have an API made with Node.js & Express that works pretty well. I then have my front project which is a simple one-page vue app that use vuex store.
On my single page I have several components and I want to add on each of them a possibility that when you're logged in as an Administrator you can click on every component to edit them.
I made it works well on static elements :
For example, here the plus button is shown as expected.
However, just bellow this one I have some components, that are loaded once the data are received. And in those components, I also have those buttons, but they're not shown. However, there's no data in this one except the title but that part is working very well, already tested and in production. It's just the "admin buttons" part that is not working as I expect it to be :
Sometimes when I edit some codes and the webpack watcher deal with my changes I have the result that appears :
And that's what I expect once the data are loaded.
There is something that I don't understand here and so I can't deal with the problem. Maybe a watch is missing or something ?
So and the code ?
First of all, we have a mixin for "Auth" that isn't implemented yet so for now it's just this :
Auth.js
export default {
computed: {
IsAdmin() {
return true;
}
},
}
Then we have a first component :
LCSkills.js
<template>
<div class="skills-container">
<h2 v-if="skills">{{ $t('skills') }}</h2>
<LCAdmin v-if="IsAdmin" :addModal="$refs.addModal" />
<LCModal ref="addModal"></LCModal>
<div class="skills" v-if="skills">
<LCSkillCategory
v-for="category in skills"
:key="category"
:category="category"
/>
</div>
</div>
</template>
<script>
import LCSkillCategory from './LCSkillCategory.vue';
import { mapState } from 'vuex';
import LCAdmin from '../LCAdmin.vue';
import LCModal from '../LCModal.vue';
import Auth from '../../mixins/Auth';
export default {
name: 'LCSkills',
components: {
LCSkillCategory,
LCAdmin,
LCModal,
},
computed: mapState({
skills: (state) => state.career.skills,
}),
mixins: [Auth],
};
</script>
<style scoped>
...
</style>
This component load each skills category with the LCSkillCategory component when the data is present in the store.
LCSkillCategory.js
<template>
<div class="skillsCategory">
<h2 v-if="category">{{ name }}</h2>
<LCAdmin
v-if="IsAdmin && category"
:editModal="$refs.editModal"
:deleteModal="$refs.deleteModal"
/>
<LCModal ref="editModal"></LCModal>
<LCModal ref="deleteModal"></LCModal>
<div v-if="category">
<LCSkill
v-for="skill in category.skills"
:key="skill"
:skill="skill"
/>
</div>
<LCAdmin v-if="IsAdmin" :addModal="$refs.addSkillModal" />
<LCModal ref="addSkillModal"></LCModal>
</div>
</template>
<script>
import LCSkill from './LCSkill.vue';
import { mapState } from 'vuex';
import LCAdmin from '../LCAdmin.vue';
import LCModal from '../LCModal.vue';
import Auth from '../../mixins/Auth';
export default {
name: 'LCSkillCategory',
components: { LCSkill, LCAdmin, LCModal },
props: ['category'],
mixins: [Auth],
computed: mapState({
name: function() {
return this.$store.getters['locale/getLocalizedValue']({
src: this.category,
attribute: 'name',
});
},
}),
};
</script>
<style scoped>
...
</style>
And so each category load a LCSkill component for each skill of this category.
<template>
<div class="skill-item">
<img :src="img(skill.icon.hash, 30, 30)" />
<p>{{ name }}</p>
<LCAdmin
v-if="IsAdmin"
:editModal="$refs.editModal"
:deleteModal="$refs.deleteModal"
/>
<LCModal ref="editModal"></LCModal>
<LCModal ref="deleteModal"></LCModal>
</div>
</template>
<script>
import LCImageRendering from '../../mixins/LCImageRendering';
import { mapState } from 'vuex';
import Auth from '../../mixins/Auth';
import LCAdmin from '../LCAdmin.vue';
import LCModal from '../LCModal.vue';
export default {
name: 'LCSkill',
mixins: [LCImageRendering, Auth],
props: ['skill'],
components: { LCAdmin, LCModal },
computed: mapState({
name: function() {
return this.$store.getters['locale/getLocalizedValue']({
src: this.skill,
attribute: 'name',
});
},
}),
};
</script>
<style scoped>
...
</style>
Then, the component with the button that is added everywhere :
LCAdmin.js
<template>
<div class="lc-admin">
<button v-if="addModal" #click="addModal.openModal()">
<i class="fas fa-plus"></i>
</button>
<button v-if="editModal" #click="editModal.openModal()">
<i class="fas fa-edit"></i>
</button>
<button v-if="deleteModal" #click="deleteModal.openModal()">
<i class="fas fa-trash"></i>
</button>
</div>
</template>
<script>
export default {
name: 'LCAdmin',
props: ['addModal', 'editModal', 'deleteModal'],
};
</script>
Again and I'm sorry it's not that I haven't look for a solution by myself, it's just that I don't know what to lookup for... And I'm also sorry for the very long post...
By the way, if you have some advice about how it is done and how I can improve it, feel free, Really. That how I can learn to do better !
EDIT :: ADDED The Store Code
Store Career Module
import { getCareer, getSkills } from '../../services/CareerService';
const state = () => {
// eslint-disable-next-line no-unused-labels
careerPath: [];
// eslint-disable-next-line no-unused-labels
skills: [];
};
const actions = {
async getCareerPath ({commit}) {
getCareer().then(response => {
commit('setCareerPath', response);
}).catch(err => console.log(err));
},
async getSkills ({commit}) {
getSkills().then(response => {
commit('setSkills', response);
}).catch(err => console.log(err));
}
};
const mutations = {
async setCareerPath(state, careerPath) {
state.careerPath = careerPath;
},
async setSkills(state, skills) {
state.skills = skills;
}
}
export default {
namespaced: true,
state,
actions,
mutations
}
Career Service
export async function getCareer() {
const response = await fetch('/api/career');
return await response.json();
}
export async function getSkills() {
const response = await fetch('/api/career/skill');
return await response.json();
}
Then App.vue, created() :
created() {
this.$store.dispatch('config/getConfigurations');
this.$store.dispatch('certs/getCerts');
this.$store.dispatch('career/getSkills');
this.$store.dispatch('projects/getProjects');
},
Clues
It seems that if I remove the v-if on the buttons of the LCAdmin, the button are shown as expected except that they all show even when I don't want them to. (If no modal are associated)
Which give me this result :
Problem is that refs are not reactive
$refs are only populated after the component has been rendered, and they are not reactive. It is only meant as an escape hatch for direct child manipulation - you should avoid accessing $refs from within templates or computed properties.
See simple demo below...
const vm = new Vue({
el: "#app",
components: {
MyComponent: {
props: ['modalRef'],
template: `
<div>
Hi!
<button v-if="modalRef">Click!</button>
</div>`
}
},
data() {
return {
}
}
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<my-component :modal-ref="$refs.modal"></my-component>
<div ref="modal">I'm modal placeholder</div>
</div>
The solution is to not pass $ref as prop at all. Pass simple true/false (which button to display). And on click event, $emit the event to the parent and pass the name of the ref as string...

How to change the colour of multiple children components when triggered by a single child component in Vue

how do you affect multiple (in this case just 2) children components owned by two different parent components when an action is triggered by one of the children components?
For example I have a component, lets call it <component-one/>. Inside this component I have something like below:
<div #mouseover="hover=true" #mouseleave="hover=false" :class="setColour">
<div class="icon-wrapper commercial-layout position-relative">
<u-button icon color="transparent" #click="toggleCommercials">
<u-icon :icon="icon" color="white"/>
</u-button>
<small class="commercial-ind">COMMERCIAL ADS</small>
<div class="commercial-layout commercial-ind">{{hide}}</div>
</div>
</div>
computed: {
setColour () {
if (this.hover) {
return 'bg-danger'
}
else if (this.commercials) {
return 'bg-primary'
}
else if (!this.commercials) {
return 'bg-secondary'
}
},
watch: {
setColour: function(val) {
console.log("val",val)
}
}
But somewhere else in the code base I have two other components, lets call them <component-two/> and <component-three/>. Inside those components I use component-one. When I push on the button from component-two I want the same effect to also be triggered in component-three, and vice versa, but I'm not quite sure how to achieve that.
Currently both component-two and component-three just have component-one. I've tried adding a watch in component-one but it doesn't really do anything other than capturing changes to the setColour computed property. (I naively thought by capturing the change, all places where component-one is used will get updated)
I'm not sure I totally understand your specific component relationships, but in general I recommend using Vuex.
Using Vue 2 and the CLI, I created sample SFCs that use Vuex to store the background color CSS style. Each child is associated with a specific color, and clicking it's button updates the color of all sibling components.
/store/index.js
import Vue from 'vue'
import Vuex from 'vuex'
Vue.use(Vuex)
export default new Vuex.Store({
state: {
commonBgColor: 'navajowhite'
},
mutations: {
updateBgColor(state, newColor) {
state.commonBgColor = newColor;
}
}
})
Parent.vue
<template>
<div class="parent">
<child initBgColor="aquamarine" instanceName="One" />
<child initBgColor="mediumorchid" instanceName="Two" />
</div>
</template>
<script>
import Child from './Child.vue'
export default {
components: {
Child
}
}
</script>
Child.vue
<template>
<div class="child">
<div class="row">
<div class="col-md-6" :style="currentBgColor">
<span>Sibling Component {{ instanceName }}</span>
<button type="button" class="btn btn-secondary" #click="updateCommonBgColor">Change All Sibling Colors</button>
</div>
</div>
</div>
</template>
<script>
export default {
props: {
initBgColor: {
type: String,
required: true
},
instanceName: {
type: String,
required: true
}
},
data() {
return {
backgroundColor: this.initBgColor
}
},
computed: {
currentBgColor() {
return 'background-color: ' + this.$store.state.commonBgColor;
}
},
methods: {
updateCommonBgColor() {
this.$store.commit('updateBgColor', this.backgroundColor);
}
}
}
</script>
<style scoped>
.child {
margin-top: 0.5rem;
}
span {
font-size: 1.5rem;
padding: 0.5rem;
}
button {
float: right;
}
</style>

Is it possible to create a vue component to render a list of global components dynamically?

I have some global-registered base components to be listed & rendered on the UI as the user drag and drop it on the layout editor. Then, I want it to be processed on a <ComponentRenderer/> component.
Inside of <ComponentRenderer/>, I currently have this kind of logic:
<template>
<div class="component-renderer">
<radio-button
:pageId="pageId"
:input="input"
:preview="preview"
v-if="input.type == 'radio'"
></radio-button>
<check-box
:pageId="pageId"
:input="input"
:preview="preview"
v-if="input.type == 'checkbox'"
></check-box>
<standard-input
:pageId="pageId"
:input="input"
:preview="preview"
v-if="input.type == 'input'"
></standard-input>
...
...
</div>
</template>
Now instead of hard-coding & comparing it manually using v-if, I want it to dynamically compare itself and render it's element and properties so that I don't need to register the other one when a new component was added. Something that looks like this:
<template>
<div class="component-renderer" v-html="preRenderComponent"></div>
</template>
<script>
export default {
props: {
targetedComponent: {
type: Object,
required: true
}
},
computed: {
preRenderComponent() {
return this.$options.components.filter(
component =>
component.extendOptions.name.toLowerCase() == "base" + this.targetedComponent.type.toLowerCase() // E.g: 'input'
);
}
}
};
</script>
Is it possible? And if possible, how could I render the element and properties? Knowing that when I do console.log(Vue.options.components) and exploring it, it does not provide the element that gonna be rendered.
First thing first, I would say thanks for Steven Spungin & Phil for giving an information about this issue.
I tried to implements it on my code and it does work as I expected. For anyone who wondering what is it looks like, here I provides the code that have been implemented.
LayoutRenderer.vue :
<template>
<GridLayout
v-if="pageComponents.length != 0"
:layout.sync="pageComponents"
:col-num="12"
:row-height="30"
:is-draggable="true"
:is-resizable="true"
:is-mirrored="false"
:vertical-compact="true"
:margin="[10, 10]"
:use-css-transforms="true"
:responsive="true"
:auto-size="true"
>
<GridItem
v-for="component in pageComponents"
:key="component.i"
:x="component.x"
:y="component.y"
:w="component.w"
:h="component.h"
:i="component.i"
>
<!-- <ComponentRenderer :component="component"></ComponentRenderer> -->
<Component :is="named(component)"></Component>
</GridItem>
</GridLayout>
</template>
<script>
import VueGridLayout from "vue-grid-layout";
export default {
components: {
GridLayout: VueGridLayout.GridLayout,
GridItem: VueGridLayout.GridItem
},
data() {
return {
pageComponents: []
};
},
created() {
this.fetchComponents();
},
methods: {
fetchComponents() {
let pageId = this.$route.params.component.pageId;
this.$store.dispatch("components/fetchComponents", pageId).then(() => {
this.pageComponents = this.$store.getters["components/components"];
});
},
named(component) {
let componentName = this.$options.filters.capitalize(component.type);
return `Base${componentName}`;
}
}
};
</script>

How to include a local JS file into Vue template

I want to import a JS file to be run along with a template in browser. I tried this, but it didn't work because I need everything loaded before my script can run.
Let me show you the problematic vue file:
<template>
<div id="canvaspage">
<canvas id="canvas"></canvas>
<div id="buttonlist">
<h5>Select your action:</h5>
<div class="col">
<button id="btn1">JS file custom action 1</button>
<button id="btn2">JS file custom action 2</button>
</div>
</div>
</div>
</template>
<script>
export default {
name: 'CanvasPage'
}
</script>
...
See that canvas and buttons on template? I want to interact with it using pure JS.
Here is an example of what the JS file is trying to do:
let canvas = document.getElementById('canvas')
let button1 = document.getElementById('btn1')
let button2 = document.getElementById('btn2')
canvas.addEventListener('click', () => {
console.log('Canvas clicked')
})
button1.addEventListener('click', () => {
console.log('Button 1 clicked')
})
button2.addEventListener('click', () => {
console.log('Button 2 clicked')
})
If I try the solution linked above, what happens is that 'canvas', 'button1' and 'button2' are all null, because JS cannot find them. How can I make it work on Vue?
I don't see a reason- in this example- why you want to do anything in external js file, why not just interact with dom the vue way - I mean, proper way? Vue can destroy or replace your element with any v-if or rerender action. You can always link to your elements with this.$refs if you want to interact with DOM directly which is lots better than querySelector thingy. But anyway, here's a dummy example:
// external js file - ./extfile.js
export function canvasClick(...args) {
console.log('canvas clicked with: ', args);
}
export function button1Click(...args) {
console.log('button1 clicked with: ', args);
}
export function button2Click(...args) {
console.log('button2 clicked with: ', args);
}
// vue component
<template>
<div id="canvaspage">
<canvas id="canvas" #click="canvasAction"></canvas>
<div id="buttonlist">
<h5>Select your action:</h5>
<div class="col">
<button id="btn1" #click.prevent="button1Action">JS file custom action 1</button>
<button id="btn2" #click.prevent="button2Action">JS file custom action 2</button>
</div>
</div>
</div>
</template>
<script>
import { canvasClick, button1Click, button2Click } from './extfile';
export default {
name: 'CanvasPage',
methods: {
canvasAction(event) { canvasClick(event, this) },
button1Action(event) { button1Click(event, this) },
button2Action(event) { button2Click(event, this) },
}
}
</script>
Objects managed by Vue are create/destroyed according to Vue' lifecycle. This means that any external code you use to query vue-managed elements should be somewhat coupled to Vue's lifecycle.
This means that, ideally, you should use Vue itself to add the behaviour you want. You should, for instance, add this new function you want into a Vue component. This guarantees a simpler design.
Alternative: If the Vue components are from third-parties, perhaps from another team which you can't count on, you could hook those event listeners to the document and check the target's id attribute instead of hooking the event listeners directly to the canvas element (which may be destroyed by Vue and the hooks lost).
document.body.addEventListener('click', (event) => {
switch (event.target.id) {
case 'canvas':
console.log('Canvas clicked');
break;
case 'btn1':
console.log('Button 1 clicked');
break;
case 'btn2':
console.log('Button 2 clicked');
break;
}
}, true);
This code makes it very obvious that if you have more than one element in the DOM with those IDs, all of them will trigger the code.
Demo:
const CanvasComponent = Vue.component('canvas-component', {
template: `#canvas-component`,
});
const BlankComponent = Vue.component('blank-component', {
template: `<div><h3>Now click back to canvas and see that the listeners still work.</h3></div>`,
});
var router = new VueRouter({
routes: [{
path: '/',
component: {template: '<div>Click one link above</div>'}
},{
path: '/blank',
component: BlankComponent,
name: 'blank'
},
{
path: '/canvas',
component: CanvasComponent,
name: 'canvas'
}
]
});
var app = new Vue({
el: '#app',
router: router,
template: `
<div>
<router-link :to="{name: 'canvas'}">canvas</router-link> |
<router-link :to="{name: 'blank'}">blank</router-link>
<router-view></router-view>
</div>
`
});
document.body.addEventListener('click', (event) => {
switch (event.target.id) {
case 'canvas':
console.log('Canvas clicked');
break;
case 'btn1':
console.log('Button 1 clicked');
break;
case 'btn2':
console.log('Button 2 clicked');
break;
}
}, true);
<script src="//unpkg.com/vue#2.6.9/dist/vue.min.js"></script>
<script src="//unpkg.com/vue-router#3.1.3/dist/vue-router.min.js"></script>
<div id="app">
<canvas-component></canvas-component>
</div>
<template id="canvas-component">
<div id="canvaspage">
<canvas id="canvas"></canvas>
<div id="buttonlist">
<h5>Select your action:</h5>
<div class="col">
<button id="btn1">JS file custom action 1</button>
<button id="btn2">JS file custom action 2</button>
</div>
</div>
</div>
</template>

Vue.js Dynamic Component - Template not showing components data

I'm trying to build a quiz-game with VueJs and up until now everything worked out smoothly, but now that I'm started using dynamic components I'm running into issues with displaying the data.
I have a start component (Start View) that I want to be replaced by the actual Quiz component ("In Progress") when the user clicks on the start button. This works smoothly. But then, in the second components template, the data referenced with {{ self.foo }} does not show up anymore, without any error message.
The way I implemented is the following:
startComponent:
startComponent = {
template: '#start-component',
data: function () {
return {
QuizStore: QuizStore.data
}
},
methods: {
startQuiz: function () {
this.QuizStore.currentComponent = 'quiz-component';
}
}
}
};
And the template:
<script type="x-template" id="start-component">
<div>
<button v-on:click="startQuiz()">
<span>Start Quiz</span>
</button>
</div>
</script>
Note: I'm using x-templates since it somehow makes the most sense with the rest of the application being Python/Flask. But everything is wrapped in {% raw %} so the brackets are not the issue.
Quiz Component:
quizComponent = {
template: '#quiz-component',
data: function () {
return {
QuizStore: QuizStore.data,
question: 'foo',
}
};
And the template:
<script type="x-template" id="quiz-component">
<div>
<p>{{ self.question }}</p>
</div>
</script>
And as you might have seen I'm using a QuizStore that stores all the states.
The store:
const QuizStore = {
data: {
currentComponent: 'start-component',
}
};
In the main .html I'm implementing the dynamic component as follows:
<div id="app">
<component :is="QuizStore.currentComponent"></component>
</div>
So what works:
The Start screen with the button shows up.
When I click on the Start Button, the quizComponent shows up as expected.
What does not work:
The {{ self.question }} data in the QuizComponent template does not show up. And it does not throw an error message.
it also does not work with {{ question }}.
What I don't understand:
If I first render the quizComponent with setting QuizStore.currentComponent = 'startComponent', the data shows up neatly.
If I switch back to <quiz-component></quiz-component> (rather than the dynamic components), it works as well.
So it seems to be the issue that this. does not refer to currently active dynamic component - so I guess here is the mistake? But then again I don't understand why there is no error message...
I can't figure out what the issue is here - anyone?
You may have some issues with your parent component not knowing about its child components, and your construct for QuizStore has a data layer that you don't account for when you set currentComponent.
const startComponent = {
template: '#start-component',
data: function() {
return {
QuizStore: QuizStore.data
}
},
methods: {
startQuiz: function() {
this.QuizStore.currentComponent = 'quiz-component';
}
}
};
const QuizStore = {
data: {
currentComponent: 'start-component',
}
};
new Vue({
el: '#app',
data: {
QuizStore
},
components: {
quizComponent: {
template: '#quiz-component',
data: function() {
return {
QuizStore: QuizStore.data,
question: 'foo'
}
}
},
startComponent
}
});
<script src="//cdnjs.cloudflare.com/ajax/libs/vue/2.4.2/vue.min.js"></script>
<script type="x-template" id="start-component">
<div>
<button v-on:click="startQuiz()">
<span>Start Quiz</span>
</button>
</div>
</script>
<script type="x-template" id="quiz-component">
<div>
<p>{{ question }}</p>
</div>
</script>
<div id="app">
<component :is="QuizStore.data.currentComponent"></component>
</div>
The following worked in the end:
I just wrapped <component :is="QuizStore.currentComponent"></component> in a parent component ("index-component") instead of putting it directly in the main html file:
<div id="app">
<index-component></index-component>
</div>
And within the index-component:
<script type="x-template" id="index-component">
<div>
<component :is="QuizStore.currentComponent"></component>
</div>
</script>
Maybe this would have been the right way all along, or maybe not, but it works now :) Thanks a lot Roy for your help!