Can't use Vue.js Data in Created () - vue.js

I'm wondering if is it possible, how can I use Vue.js data in my Created() function.
I'll show some code so you can see why I say.
data (){
return {
model: {},
foo: 'boo'
}
},
created (){
const getModel = () => {
const modelId = this.$route.params.id
axios.get('/api/model', { params: {modelId: modelId}})
.then(res => {
this.model = res.data
this.boo = 'hello'
console.log(this.model)
console.log(this.foo)
})
.catch(err => console.log(err))
}
getModel()
const init = () =>{
console.log(this.model)
console.log(this.foo)
}
init()
The first console.log(foo) returns 'hello'.
The second one (init) returns 'boo'.
Also the first console.log(this.model) is what I expect to get but once is out of the axios method it's like empty again all over the mounted function.
I've tried a lot of things but none of them worked, hope I get a solution... Thanks in advance!

As soon as JS functions are non-blocking - your axios call isn't done (model is still empty) when you call for init
Define init as components method
Call this.init() in axios.get callback

It might have to do with the fact that in your created hook you're creating a function using the function keyword, which means your init function will have its own context(its own this).
A solution to this problem would be to use an arrow function.
data () { return { foo: 'bar' } }
created () {
const init = () => {
console.log(this.foo);
}
init(); // bar
}
More about arrow functions
UPDATE
Actually, the issue stems from not awaiting for getModel. Because you are making a request, you first need to wait for the promise to resolve, and then use its resolved data in the code that depends on it.
The async/await version would be:
async created () {
const getModel = async () => {
const modelId = this.$route.params.id
try {
const res = await axios.get('/api/model', { params: {modelId: modelId}})
this.model = res.data
this.boo = 'hello'
console.log(this.model)
console.log(this.foo)
} catch (err) {
console.error(err)
}
}
const init = () =>{
console.log(this.model)
console.log(this.foo)
}
// An async function always returns a promise
await getModel();
init();
}

Related

Vuejs created and mounted doesn't work properly even if at the same level than methods

I'm experiencing a strange behaviour with created() and mounted() in Vue.js. I need to set 2 lists in created() - so it means those 2 lists will help me to create a third list which is a merge.
Here is the code :
// return data
created () {
this.retrieveSellOffers();
this.getAllProducts();
},
mounted () {
this.mergeSellOffersProducts();
},
methods: {
retrieveSellOffers() {
this.sellerId = localStorage.sellerId;
SellOfferServices.getAllBySellerId(this.sellerId)
.then((response) => {
this.sellOffers = response.data;
console.log("this.sellOffers");
console.log(this.sellOffers);
})
.catch((e) => {
console.log(e);
});
},
getAllProducts() {
ProductServices.getAll()
.then((response) => {
this.products = response.data;
console.log("this.products");
console.log(this.products);
})
.catch((e) => {
console.log(e);
});
},
mergeSellOffersProducts () {
console.log(this.products) // print empty array
console.log(this.sellOffers) // print empty array
for (var i = 0; i < this.sellOffers.length; i++) {
if (this.sellOffers[i].productId === this.products[i]._id) {
this.arr3.push({id: this.sellOffers[i]._id, price: this.sellOffers[i].price, description: this.products[i].description});
}
}
this.arr3 = this.sellOffers;
},
}
//end of code
So my problem is when I enter in mergeSellOffersProducts(), my 2 lists are empty arrays :/
EDIT :
This way worked for me :
async mounted() {
await this.retrieveSellOffers();
await this.getAllProducts();
this.mergeSellOffersProducts();
},
methods: {
async retrieveSellOffers() {
this.sellerId = localStorage.sellerId;
this.sellOffers = (await axios.get('link/api/selloffer/seller/', { params: { sellerId: this.sellerId } })).data;
},
async getAllProducts() {
this.products = (await axios.get('link/api/product')).data;
},
}
I think the reason is: Vue does not wait for the promises to resolve before continuing with the component lifecycle.
Your functions retrieveSellOffers() and getAllProducts() contain Promise so maybe you have to await them in the created() hook:
async created: {
await this.retrieveSellOffers();
await this.getAllProducts();
}
So I tried to async my 2 methods :
async retrieveSellOffers() {
this.sellerId = localStorage.sellerId;
this.sellOffers = (await axios.get('linkhidden/api/selloffer/', { params: { sellerId: '615b1575fde0190ad80c3410' } })).data;
console.log("this.sellOffers")
console.log(this.sellOffers)
},
async getAllProducts() {
this.products = (await axios.get('linkhidden/api/product')).data;
console.log("this.products")
console.log(this.products)
},
mergeSellOffersProducts () {
console.log("here")
console.log(this.sellOffers)
console.log(this.products)
this.arr3 = this.sellOffers;
},
My data are well retrieved, but yet when I enter in created, the two lists are empty...
You are calling a bunch of asynchronous methods and don't properly wait for them to finish, that's why your data is not set in mounted. Since Vue does not await its lifecycle hooks, you have to deal with the synchronization yourself.
One Vue-ish way to fix it be to replace your method mergeSellOffersProducts with a computed prop (eg mergedSellOffersProducts). Instead of generating arr3 it would simply return the merged array. It will be automatically updated when products or sellOffers is changed. You would simply use mergedSellOffersProducts in your template, instead of your current arr3.
If you only want to update the merged list when both API calls have completed, you can either manually sync them with Promise.all, or you could handle this case in the computed prop and return [] if either of the arrays is not set yet.
When you're trying to merge the 2 lists, they aren't filled up yet. You need to await the calls.
async created () {
await this.retrieveSellOffers();
await this.getAllProducts();
},
async mounted () {
await this.mergeSellOffersProducts();
},

How to set mock nuxt asyncData in jest

I am using Nuxt.js and want to test my page which uses asyncData with Jest. I have a factory function to set up my wrapper, but it basically returns a shallowMount.
Expected
When clicking a button I want the function to behave differently depending on the query parameter. When running the test I want to mock this by setting it directly when creating the wrapper (Similar to setting propsData). E.g. const wrapper = factory({ propsData: { myQueryParam: 'some-value' } });
Result
However trying to set propsData still returns undefined: console.log(wrapper.vm.myQueryParam); // undefined while I would expect it to be 'some-value'
Question
Is there a different approach on how I can test this function that relies on query parameters?
Because asyncData is called before Vue is initialised, it means shallowMount doesn't work right out of the box.
Example:
page:
<template>
<div>Your template.</div>
</template>
<script>
export default {
data() {
return {}
},
async asyncData({
params,
error,
$axios
}) {
await $axios.get("something")
}
}
</script>
test:
import { shallowMount } from "#vue/test-utils";
describe('NewsletterConfirm', () => {
const axiosGetMock = jest.fn()
const axiosPostMock = jest.fn()
var getInitialised = async function (thumbprint) {
if (thumbprint == undefined) throw "thumbprint not provided"
let NewsletterConfirm = require('./_thumbprint').default
if (!NewsletterConfirm.asyncData) {
return shallowMount(NewsletterConfirm);
}
let originalData = {}
if (NewsletterConfirm.data != null) {
originalData = NewsletterConfirm.data()
}
const asyncData = await NewsletterConfirm.asyncData({
params: {
thumbprint
},
error: jest.fn(),
$axios: {
get: axiosGetMock,
post: axiosPostMock
}
})
NewsletterConfirm.data = function () {
return {
...originalData,
...asyncData
}
}
return shallowMount(NewsletterConfirm)
}
it('calls axios', async () => {
let result = await getInitialised("thumbprint")
expect(axiosGetMock).toHaveBeenCalledTimes(1)
});
});
Credits to VladDubrovskis for his comment: in this nuxt issue

How to use debounce with Vuex?

I am trying to debounce a method within a Vuex action that requires an external API.
// Vuex action:
async load ({ state, commit, dispatch }) {
const params = {
period: state.option.period,
from: state.option.from,
to: state.option.to
}
commit('SET_EVENTS_LOADING', true)
const res = loadDebounced.bind(this)
const data = await res(params)
console.log(data)
commit('SET_EVENTS', data.collection)
commit('SET_PAGINATION', data.pagination)
commit('SET_EVENTS_LOADING', false)
return data
}
// Debounced method
const loadDebounced = () => {
return debounce(async (params) => {
const { data } = await this.$axios.get('events', { params })
return data
}, 3000)
}
The output of the log is:
[Function] {
cancel: [Function]
}
It is not actually executing the debounced function, but returning to me another function.
I would like to present a custom debounce method which you can use in your vuex store as
let ongoingRequest = undefined;
const loadDebounced = () => {
clearTimeout(ongoingRequest);
ongoingRequest = setTimeout(_ => {
axios.get(<<your URL>>).then(({ data }) => data);
}, 3000);
}
This method first ensures to cancel any ongoing setTimeout in the pipeline and then executes it again.
This can be seen in action HERE

how to receive a take with runSaga / redux-saga

I created a recordSaga function, its target is to record what actions have been dispatched during the saga.
export const recordSaga = async (saga, initialAction, state) => {
const dispatched = [];
const done = await runSaga(
{
dispatch: action => dispatched.push(action),
getState: () => state,
},
saga,
initialAction,
).done;
return {
dispatched,
done,
};
};
so let's say my saga is this one
export function* mySaga() {
const needToSave = yield select(needToSaveDocument);
if (needToSave) {
yield put(saveDocument());
yield take(SAVE_DOCUMENT_SUCCESS);
}
yield put(doSomethingElse())
}
I want to write two tests, which I expect to be the following
describe('mySaga', async () => {
it('test 1: no need to save', async () => {
const state = { needToSave: false }
const { dispatched } = await recordSaga(mySaga, {}, state);
expect(dispatched).toEqual([
doSomethingElse()
])
})
it('test 2: need to save', async () => {
const state = { needToSave: true }
const { dispatched } = await recordSaga(mySaga, {}, state);
expect(dispatched).toEqual([
saveDocument(),
doSomethingElse()
])
})
})
However, for the test 2 where there is a take in between, and of course jest (or its girlfriend jasmine) is yelling at me: Timeout - Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL.
I know it is because runSaga is waiting for the take(SAVE_DOCUMENT_SUCCESS), but how can I mock that up ?
The answer stdChannel().put({type, payload})
Why ?
Using stdChannel you can dispatch after the first run.
How ?
import stdChannel;
add to the first param in runSaga;
call stdChannel().put(SAVE_DOCUMENT_SUCCESS);
Example
what worked for me
I left the first test as it is the expected final result, but the solution comes on the last 2.
import { runSaga, stdchannel } from 'redux-saga'
let dispatchedActions = [];
let channel;
let fakeStore;
beforeEach(() => {
channel = stdChannel(); // you have to declare the channel to have access to it later
fakeStore = {
channel, // add it to the store in runSaga
getState: () => "initial",
dispatch: (action) => dispatchedActions.push(action),
};
});
afterEach(() => {
global.fetch.mockClear();
});
it("executes getData correctly", async () => {
await runSaga(fakeStore, getData, getAsyncData("test")).toPromise();
expect(global.fetch.mock.calls.length).toEqual(1);
expect(dispatchedActions[0]).toEqual(setData(set_value));
});
it("triggers takeLatest and call getData(), but unfortunately doesn't resolve promise", async () => {
await runSaga(fakeStore, rootSaga)// .toPromise() cannot be used here, as will throw Timeout error
channel.put(getAsyncData("test")); // if remove this line, the next 2 expects() will fail
expect(global.fetch.mock.calls.length).toEqual(1);
// expect(dispatchedActions[1]).toEqual(setData(set_value)); // will fail here, but pass on the next it()
});
it("takes the promised data from test above", () => {
expect(dispatchedActions[1]).toEqual(setData(set_value));
});
this answer (about true code, not tests) helped me
By looking at recordSaga:
export const recordSaga = async (saga, initialAction, state) => {
It seems that you should pass {type: SAVE_DOCUMENT_SUCCESS} as a second argument (i.e initialAction). That should trigger the take effect.

Promise isn't working in react component when testing component using jest

Good day. I have the following problem:
I have an item editor.
How it works: I push 'Add' button, fill some information, click 'Save' button.
_onSaveClicked function in my react component handles click event and call function from service, which sends params from edit form to server and return promise.
_onSaveClicked implements
.then(response => {
console.log('I\'m in then() block.');
console.log('response', response.data);
})
function and waits for promise result. It works in real situation.
I created fake service and placed it instead of real service.
Service's function contains:
return Promise.resolve({data: 'test response'});
As you can see fake service return resolved promise and .then() block should work immediatly. But .then() block never works.
Jest test:
jest.autoMockOff();
const React = require('react');
const ReactDOM = require('react-dom');
const TestUtils = require('react-addons-test-utils');
const expect = require('expect');
const TestService = require('./service/TestService ').default;
let testService = new TestService ();
describe('TestComponent', () => {
it('correct test component', () => {
//... some initial code here
let saveButton = TestUtils.findRenderedDOMComponentWithClass(editForm, 'btn-primary');
TestUtils.Simulate.click(saveButton);
// here I should see response in my console, but I don't
});
});
React component save function:
_onSaveClicked = (data) => {
this.context.testService.saveData(data)
.then(response => {
console.log('I\'m in then() block.');
console.log('response', response.data);
});
};
Service:
export default class TestService {
saveData = (data) => {
console.log('I\'m in services saveData function');
return Promise.resolve({data: data});
};
}
I see only "I'm in services saveData function" in my console.
How to make it works? I need to immitate server response.
Thank you for your time.
You can wrap your testing component in another one like:
class ContextInitContainer extends React.Component {
static childContextTypes = {
testService: React.PropTypes.object
};
getChildContext = () => {
return {
testService: {
saveData: (data) => {
return {
then: function(callback) {
return callback({
// here should be your response body object
})
}
}
}
}
};
};
render() {
return this.props.children;
}
}
then:
<ContextInitContainer>
<YourTestingComponent />
</ContextInitContainer>
So your promise will be executed immediately.