while trying to write a component test by using vue test utils, testing interaction between child components and stuff, I am stuck due to usage of Vuelidate from child components. Below is an example simplified:
// parent component code
<template>
<div>
<childA />
</div>
</template>
//childA code
<template>
<input v-model="value" />
</template>
<script>
...
validations: {
value: {
required
}
}
...
</script>
// parent component test
...
const wrapper = mount(MyParentComponent, {
...,
components: {
childA,
},
validations: {
value: required
},
...
})
I have tried to find a solution out there that I could mount (note here that I WANT to mount also the child components, so shallow-mount is not what I look for) the child component, with it's respective Vuelidate validation rules, but I still haven't found any solution.
Instead, my test gives me errors like:
Cannot read property `value` of undefined
which makes sense, since the test cannot access the child component's $v instance.
Has anyone achieved it so far?
For answering your question and after i've did some test i believe you missed the data part inside your mount
mount: render child components
shallowMount: doesn't render child components
MyParentComponent need to have in the options the structure of you're child component so this is why he is returning the error
And i saw that you're passing the import of your component directly but don't forget that your test folder is outside of your src folder
import ChildA from "#/components/ChildA";
will not work instead i propose to use absolute path directly to import your child component or use a configuration to resolve them
const wrapper = mount(MyParentComponent, {
data() {
return {
value: null
}
},
components: {
ChildA: () => import('../../src/components/ChildA'),
},
validations: {
value: required
},
})
Related
My app structure is as follows. The Parent app has an editable form, with a child component list placed at the side. The child component is a list of students in a table.
I'm trying to update a child component list. The child component uses a 'v-for', the list is generated through a web service call using Axios.
In my parent component, I am editing a students name, but the students new name is not reflected in the List that I have on screen.
Example:
Notice on the left the parent form has the updated name now stored in the DB. However, the list (child component) remains unchanged.
I have tried a few things such as using props, ref etc. I am starting to think that my app architecture may be incorrect.
Does anyone know how I might go about solving this issue.
Sections of the code below. You may understand that I am a novice at Vue.
Assistance much appreciated.
// Child component
<component>
..
<tr v-for="student in Students.slice().reverse()" :key="student._id">
..
</component>
export default {
env: '',
// list: this.Students,
props: {
inputData: Boolean,
},
data() {
return {
Students: [],
};
},
created() {
// AXIOS web call...
},
};
// Parent component
import List from "./components/students/listTerms";
export default {
name: "App",
components: {
Header,
Footer,
List,
},
};
// Implementation
<List />
I think that it is better to use vuex for this case and make changes with mutations. Because when you change an object in the data array, it is not overwritten. reactivity doesn't work that way read more about it here
If your list component doesn't make a fresh API call each time the form is submitted, the data won't reflect the changes. However, making a separate request each time doesn't make much sense when the component is a child of the form component.
To utilise Vue's reactivity and prevent overhead, it would be best to use props.
As a simplified example:
// Child component
<template>
...
<tr v-for="student in [...students].reverse()" :key="student._id">
...
</template>
<script>
export default {
props: {
students: Array,
},
};
</script>
// Parent component
<template>
<div>
<form #submit.prevent="submitForm">
<input v-model="studentData.name" />
<input type="submit" value="SUBMIT" />
</form>
<List :students="students" />
</div>
</template>
<script>
import List from "./components/students/listTerms";
export default {
name: "App",
components: {
List,
},
data() {
return {
students: [],
studentData: {
name: ''
}
}
},
methods: {
submitForm() {
this.$axios.post('/endpoint', this.studentData).then(() => {
this.students.push({ ...this.studentData });
}).catch(err => {
console.error(err)
})
}
}
};
</script>
Working example.
This ensures data that isn't stored successfully won't be displayed and data that is stored successfully reflects in the child component.
I am trying to make a visual representation of a component library. I am using dynamic <component>s to render each component. However, as I am populating the component with its slots, I am running into issues due to parent methods missing.
I want the components to be usable (demo) therefore I need to compensate for this.$parent not working.
<template>
<component v-bind:is="'s-' + comp.name" v-bind="props" ref="comp"> <!-- this is the corrent parent-->
<div v-if="comp.slots">
<div
v-for="(slot, i) in comp.slots"
v-bind:key="i"
v-bind:slot="slot.name"
>
<div v-if="slot.type == 'component'"> <!-- childs parent -->
<de-mo v-bind:comp="slot" /> <!-- this is the child calling a method on the parent -->
</div>
<div v-html="slot.value" v-else></div>
</div>
</div>
</component>
</template>
<script>
export default {
name: 'deMo',
computed: {
props() {
if (this.comp.props) {
return this.comp.props.reduce((a, r) => {
a[r.name] = r.value
return a
}, {})
}
}
},
props: {
comp: {
type: Object,
required: true
}
},
methods: this.$ref.comp.methods, //<-- this is an error
mounted(){
console.log(this.$ref.comp.methods)
}
},
</script>
<style></style>
1) Is there a way to copy the methods from the parent into this "demo" component via the ref attr
2) Alternatively, is there a better method to produce the same results?
Thanks
you can try to spread parent methods in a beforeCreate lifecycle as at this point your parent will be created and your component is going to register its all methods,
beforeCreate() {
this.$options.methods = { ...this.$parent.$options.methods };
},
however you can not access any refs in this as refs are only registered after mount of the component.
Note: Any library should use provide and inject to communicate with their component instead of referencing the parent component directly.
You can use an Event bus to communicate between components that aren't directly related to each other. Also, this is the recommended way of communication from child to parent in Vue.
bus.js
import Vue from 'vue'
export default new Vue()
demo.vue // child component that wants to call a method in the parent
import Bus from './bus.js'
export default {
mounted () {
// [1] child component will emit an event in the bus when it want to call a method of parent
Bus.$emit('invoke-parent-fn', 'param')
}
}
parent.vue // parent component where you want to render other components dynamically
import Bus from './bus.js'
export default {
methods: {
fn (param) {
console.log('// do something ' + param)
}
},
mounted () {
// [2] parent will be listening to the bus event, when child will emit an event, the handler passed in to the listener will be invoked
// [3] invoke the required method in the handler
Bus.$on('invoke-parent-fn', param => this.fn(param))
}
}
I'm writing some tests using vue-test-util for a component I've made. I have boiled my code down to the actual problem.
The component is of the form:
<template>
<inner-component>
</template>
<script>
export default {
name: 'MyList'
}
</script>
and my inner component looks something like this:
<template>
<div v-if="open">Some stuff</div>
</template>
<script>
export default {
name: 'InnerComponent',
props: {
open: false,
}
}
</script>
Now the test I'm writing is testing for the existence of the div in the inner-component when the open prop is set to true, but it is set to false by default. I need a way to set the prop of this child component before I test it.
My test:
import { createLocalVue, mount } from '#vue/test-utils'
import MyList from '#/components/MyList.vue'
describe('My Test', () => {
const localVue = createLocalVue()
const wrapper = mount(MyList)
it('Tests', () => {
// need to set the prop here
expect(wrapper.find('div').exists()).toBeTruthy()
}
}
I can use:
wrapper.vm.$children[0].$options.propsData.open = true
Which does appear to set the prop, but my tests still come up as receiving false.
I can change the component so the default is true and then my tests pass so I don't think it's the way I'm checking.
If anyone can spot why this isn't working or knows a better way to come at it, please let me know!
According to the guide:
vm.$options
The instantiation options used for the current Vue instance.
So, $options is not what we write in props.
Use $props to set property for a child component:
wrapper.vm.$children[0].$props.open = true
But this way leads to the warning:
Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or computed property based on the prop's value.
So, let's follow the advice and bind property of the child component with data of the parent component. Here I bind it with isOpen variable:
<template>
<inner-component :open='isOpen'></inner-component>
</template>
<script>
import InnerComponent from '#/components/InnerComponent.vue'
export default {
name: 'MyList',
data() {
return {
isOpen: false
}
},
components:{InnerComponent}
}
</script>
Then in your test, you can just change the value of isOpen when you want to change the value of open property in the child component:
wrapper.setData({isOpen:true})
With the vue-test-util you can use the methods setProps from the wrapper, check the relative docs here
For example
const wrapper = mount(Foo)
wrapper.setProps({ foo: 'bar' })
I would like to create Side Panel as a reusable component in Framework7 with VueJS. Here is my code..
Card.vue
<f7-card>
<f7-card-header>Card header content</f7-card-header>
<f7-card-content><img src="https://wiki.videolan.org/images/Ubuntu-logo.png"></img></f7-card-content>
<f7-card-footer>Card footer content</f7-card-footer>
</f7-card>
Now i registered as a component like below,
import Vue from 'vue'
export default [
{
path: '/card/',
component: require('./Card')
},
]
In later vues i imported as,
import Card from './Card.vue'
and i try to access in another vues like,
Now i'm getting an error like
[Vue warn]: Unknown custom element: - did you register the
component correctly? For recursive components, make sure to provide
the "name" option.
Can anyone help me where have i mistaken?
Thanks,
It's not really clear from your code exactly what you are doing, but the error you are getting happens when you try to use a component as a child of another component without registering it in the parent's components setting like this:
<script>
import Card from './Card.vue'
export default {
data () {
return {
somedata: 'some value'
}
},
components: {Card: Card}, // <- you're missing this
// etc...
}
</script>
You can also register components globally. More here: https://v2.vuejs.org/v2/guide/components.html#Local-Registration
Are you showing us all of Card.vue? For a valid single-file vue component, I would expect to see <template>, <script> and <style> elements. The render function will be generated from whatever you put in the <template> element.
Make sure that the component that you want to reuse is wrapped inside a template tag
As follows
<template>
<div>
<component data/>
<div/>
<template/>
Then register it inside the parent
Like so
export default {
name: "Card",
components: {
Card
},
};
I don't understand how to pass data loaded by a 'route Component' to a 'subRoute Component'..
(I'm using Vue.js with Vue-router)
My router looks like that:
router.map({
'/a': {
component: A,
subRoutes: {
'/b': {
component: B
},
'/c': {
component: C
}
}
}
});
I just want to share data loaded by component A with component B and C.
Thanks in advance !
You have two simple options.
The ugly
Use the $parent option from the subroute components. That give you access to the parent instance, it's not the recommended way, but it's effective
// from the child component
this.$parent.someData
The good
Use props. Props give you the chance to pass any data from the parent to a child. It's better, because prevents error (you pass data not an instance) and you pass only what you need, even if it isn't part of the parent data.
// parent component
<template>
<child :childsdata="parentdata"></child>
</template
<script>
export default {
data: function () {
return {
parentdata: 'Hello!'
}
}
}
</script>
// child component
<template>
{{ childsdata }} <!-- prints "Hello!" -->
</template>
<script>
export default {
props: {
childsdata: {
type: String
}
}
}
</script>