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Wait x seconds for new emitted value before triggering a function

I have a child component that emits a value, and in the parent I perform an axios call with this value each time it is emitted. My problem is that I want to trigger the axios call only if in x ms (or seconds) the child has not emmited another value in order to reduce the amount of calls I do.
Code here :
<script>
import axios from "axios";
import DataTable from './DataTable.vue';
export default {
name: 'Test',
data() {
return {
gamertags: [],
// Utils
timeout: 500,
delay: 500
}
},
methods: {
// API calls
async getGamerTags(string='') {
const path = `http://localhost:5000/gamertags?string=${string}`
await axios.get(path)
.then((res) => {
this.gamertags = res.data;
})
.catch((error) => {
console.error(error);
});
},
// DataTable
handleFilters(filters) {
clearTimeout(this.timeout);
this.timeout = setTimeout(this.getGamerTags(filters.find(o => o.field == "playerGamerTag").filter), this.delay);
}
}
components: {
DataTable
}
};
</script>
<template>
<DataTable
#filters="handleFilters"
/>
</template>
Thanks in advance.

What you need is debouncing. Here is an example:
var timeout, delay = 3000;
function func1() {
clearTimeout(timeout);
timeout = setTimeout(function(){
alert("3000 ms inactivity");
}, delay);
}
<input type="text" oninput="func1()">
When emitted, simply call func1(), and if there are no new emissions after 3000 ms, the function in timeout will be executed.

It would be better to understand the problem and use case if you add the code also.
but As I could understand the problem these is two way
if you using inside input and triggering based #changed event you can add #change.lazy this not trigger on each change.
second solution is to use setTimeout(function,delayInMs) inside parent
vuejs Docs link

By simply changing the handleFilters function to :
handleFilters(filters) {
clearTimeout(this.timeout);
this.timeout = setTimeout(
this.getGamerTags,
this.delay,
filters.find(o => o.field == "playerGamerTag").filter
);
},
the problem is solved.

Can I change and commit the state inside settimeout function in Vuex?

form(#submit.prevent="onSubmit")
input(type="text" v-model="platform" placeholder="Add platform name...")
input(type="submit" value="Submit" class="button" #click="clicked = true")
button(type="button" value="Cancel" class="btn" #click="cancelNew") Cancel
h3(v-if="clicked") Thank you for adding a new platform
span {{ countdown }}
This is my template and when the user submits the form, I want to count down from 3 using setTimeout function and submit after 3 seconds.
If I have it this way, it works;
data() {
return {
countdown: 3,
platform: ""
}
},
methods: {
countDownTimer() {
setTimeout(() => {
this.countdown -= 1
this.countDownTimer()
}, 1000)
},
onSubmit() {
let newplatform = {
name: this.platform
}
this.addPlatform(newplatform)
this.platform = ' '
this.countDownTimer()
}
}
However I have 3 more forms and I didn't want to repeat the code. So I wanted to put countdown in the store,
countDownTimer({commit}) {
setTimeout(() => {
countdown = state.countdown
countdown -= 1
commit('COUNTDOWN', countdown)
this.countDownTimer()
}, 1000)
}
and mutate it like
COUNTDOWN(state, countdown) {
state.countdown = countdown
}
This doesn't work and I am not sure If I am able to change the state, commit the changes inside of settimeout function? Is there a better way I can implement this?

The issues:
The recursive setTimeout isn't stopped.
The countdown timer isn't reset.
Use setInterval (and clearInterval) instead of the recursive setTimeout.
For async logic including setTimeout, use an action rather than a mutation.
Include state from the context object (where you get commit), or it will be undefined.
Try this:
actions: {
countDownTimer({ state, commit, dispatch }) { // state, commit, dispatch
commit('RESET');
const interval = setInterval(() => { // Use `setInterval` and store it
commit('COUNTDOWN');
if (state.countdown === 0) {
clearInterval(interval); // Clear the interval
dispatch('updateDatabase'); // Call another action
}
}, 1000)
}
}
mutations: {
RESET(state) {
state.countdown = 3;
},
COUNTDOWN(state) {
state.countdown--;
}
}

How do I use axios response in different components without using export?

As the tittle says, I would like to be able to use the same axios response for differents components.
I have some restrictions like, I'm onlyl able to use react by adding scripts tags to my html so things like exports or jsx are impossible for me.
This is my react code:
class User extends React.Component {
state = {
user: {}
}
componentWillMount() {
console.log(localStorage.getItem("user"))
axios.get('http://localhost:8080/dashboard?user=' + localStorage.getItem("user"))
.then(res => {
const userResponse = res.data
setTimeout(() =>
this.setState({user: userResponse.user}), 1000);
})
}
render () {
const {user} = this.state
if (user.fullName === undefined)
return React.createElement("div", null, 'loading..');
return React.createElement("span", {className: "mr-2 d-none d-lg-inline text-gray-600 small" }, user.fullName);
}
}
ReactDOM.render( React.createElement(User, {}, null), document.getElementById('userDropdown') );
class Roles extends React.Component{
state = {
user: {}
}
componentWillMount() {
console.log(localStorage.getItem("user"))
axios.get('http://localhost:8080/dashboard?user=' + localStorage.getItem("user"))
.then(res => {
const userResponse = res.data
setTimeout(() =>
this.setState({user: userResponse.user}), 1000);
})
}
render () {
const {user} = this.state
const roles = user.user.roles.map((rol) => rol.roleName)
if (user.fullName === undefined)
return React.createElement("div", null, 'loading..');
return React.createElement("a", {className: "dropdown-item" }, user.fullName);
}
}
ReactDOM.render( React.createElement(Roles, {}, null), document.getElementById('dropdownRol') );
I would like to be able to manage different components(rendering each one) with data of the same axios response.
Is this possible considering my limitations?
Thanks in advance

Here's a working example of how you might do it. I've tried to annotate everything with comments, but I'm happy to try to clarify if you have questions.
// Fake response object for the store's "load" request
const fakeResponse = {
user: {
fullName: "Carolina Ponce",
roles: [
{ roleName: "administrator" },
{ roleName: "editor" },
{ roleName: "moderator" },
{ roleName: "generally awesome person" }
]
}
};
// this class is responsible for loading the data
// and making it available to other components.
// we'll create a singleton for this example, but
// it might make sense to have more than one instance
// for other use cases.
class UserStore {
constructor() {
// kick off the data load upon instantiation
this.load();
}
// statically available singleton instance.
// not accessed outside the UserStore class itself
static instance = new this();
// UserStore.connect creates a higher-order component
// that provides a 'store' prop and automatically updates
// the connected component when the store changes. in this
// example the only change occurs when the data loads, but
// it could be extended for other uses.
static connect = function(Component) {
// get the UserStore instance to pass as a prop
const store = this.instance;
// return a new higher-order component that wraps the connected one.
return class Connected extends React.Component {
// when the store changes just force a re-render of the component
onStoreChange = () => this.forceUpdate();
// listen for store changes on mount
componentWillMount = () => store.listen(this.onStoreChange);
// stop listening for store changes when we unmount
componentWillUnmount = () => store.unlisten(this.onStoreChange);
render() {
// render the connected component with an additional 'store' prop
return React.createElement(Component, { store });
}
};
};
// The following listen, unlisten, and onChange methods would
// normally be achieved by having UserStore extend EventEmitter
// instead of re-inventing it, but I wasn't sure whether EventEmitter
// would be available to you given your build restrictions.
// Adds a listener function to be invoked when the store changes.
// Called by componentWillMount for connected components so they
// get updated when data loads, etc.
// The store just keeps a simple array of listener functions. This
// method creates the array if it doesn't already exist, and
// adds the new function (fn) to the array.
listen = fn => (this.listeners = [...(this.listeners || []), fn]);
// Remove a listener; the inverse of listen.
// Invoked by componentWillUnmount to disconnect from the store and
// stop receiving change notifications. We don't want to attempt to
// update unmounted components.
unlisten = fn => {
// get this.listeners
const { listeners = [] } = this;
// delete the specified function from the array.
// array.splice modifies the original array so we don't
// need to reassign it to this.listeners or anything.
listeners.splice(listeners.indexOf(fn), 1);
};
// Invoke all the listener functions when the store changes.
// (onChange is invoked by the load method below)
onChange = () => (this.listeners || []).forEach(fn => fn());
// do whatever data loading you need to do here, then
// invoke this.onChange to update connected components.
async load() {
// the loading and loaded fields aren't used by the connected
// components in this example. just including them as food
// for thought. components could rely on these explicit fields
// for store status instead of pivoting on the presence of the
// data.user object, which is what the User and Role components
// are doing (below) in this example.
this.loaded = false;
this.loading = true;
try {
// faking the data request. wait two seconds and return our
// hard-coded data from above.
// (Replace this with your network fetch.)
this.data = await new Promise(fulfill =>
setTimeout(() => fulfill(fakeResponse), 2000)
);
// update the loading/loaded status fields
this.loaded = true;
this.loading = false;
// call onChange to trigger component updates.
this.onChange();
} catch (e) {
// If something blows up during the network request,
// make the error available to connected components
// as store.error so they can display an error message
// or a retry button or whatever.
this.error = e;
}
}
}
// With all the loading logic in the store, we can
// use a much simpler function component to render
// the user's name.
// (This component gets connected to the store in the
// React.createElement call below.)
function User({ store }) {
const { data: { user } = {} } = store || {};
return React.createElement(
"span",
{ className: "mr-2 d-none d-lg-inline text-gray-600 small" },
user ? user.fullName : "loading (User)…"
);
}
ReactDOM.render(
// Connect the User component to the store via UserStore.connect(User)
React.createElement(UserStore.connect(User), {}, null),
document.getElementById("userDropdown")
);
// Again, with all the data loading in the store, we can
// use a much simpler functional component to render the
// roles. (You may still need a class if you need it to do
// other stuff, but this is all we need for this example.)
function Roles({ store }) {
// get the info from the store prop
const { data: { user } = {}, loaded, loading, error } = store || {};
// handle store errors
if (error) {
return React.createElement("div", null, "oh noes!");
}
// store not loaded yet?
if (!loaded || loading) {
return React.createElement("div", null, "loading (Roles)…");
}
// if we made it this far, we have user data. do your thing.
const roles = user.roles.map(rol => rol.roleName);
return React.createElement(
"a",
{ className: "dropdown-item" },
roles.join(", ")
);
}
ReactDOM.render(
// connect the Roles component to the store like before
React.createElement(UserStore.connect(Roles), {}, null),
document.getElementById("dropdownRol")
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="userDropdown"></div>
<div id="dropdownRol"></div>

react component this.value is null even when it's populated

Here a simplified version of a React component I have:
class Example extends Component {
constructor(props) {
super(props);
this.state = {key : 10 };
this.value = null;
}
componentDidMount() {
this.fetchValueFromServer();
this.fetchSecondValueFromServer();
}
fetchValueFromServer() {
fetch_value_from_server(this.state.key).then( (value) => {
this.value = value;
});
}
fetchSecondValueFromServer() {
is_ready(this.value).then(() => {
console.log("there");
});
}
}
I expect to see the console.log("there") printed but this.value always remains null, even thou is set in the fetchValueFromServer. Why is this?
if you are curious to how is_ready looks it's a simple promise:
function is_ready(variable) {
return new Promise((resolve, reject) => {
let interval = setInterval(() =>
{
if (variable) {
clearInterval(interval);
resolve();
}
}, 100);
});
}

The problem is with the logic of the is_ready function. It looks like you want that function to repeatedly check if that value is there, then resolve when it is. However, because of how closures in JS work, that variable argument will only ever have one value in the context of that function's body, even after this.value changes. Look at this small example:
let secret = 'not found yet'
function checkSecret(secretArg) {
setInterval(() => {
console.log(secretArg)
}, 500)
}
checkSecret(secret)
setTimeout(() => { secret = 'secret found!' }, 1000)
This code will always print 'not found yet', because it's checking the secretArg variable that's been assigned locally, and not the secret variable directly.

Looks like you need to resolve with the variable value within the function is_ready, like so:
resolve(variable);
Then add a param to your console log to determine more, like so:
fetchSecondValueFromServer() {
is_ready(this.value).then((returnValue) => {
console.log("there", returnValue);
});
}

figured it, the value in is_ready is passed by value! Javascript needs to implement & so we can pass crap by ref!

Autosave to database after timeout

I want to perform autosave when a user fills out a form in a React component. The ajax call should be triggered when 3 seconds has passed since last onChange event.
My code below is inspired from an instructive article which shows how to accomplish this with setTimeout and clearTimeout. But I'm doing something wrong in my React implementation - the 3 sec delay isn't respected when typing.
Any ideas what's wrong here? Or is my thinking all together wrong about how to solve this?
class Form extends Component {
constructor() {
super();
this.state = {
isSaved: false
};
this.handleUserInput = this.handleUserInput.bind(this);
this.saveToDatabase = this.saveToDatabase.bind(this);
}
saveToDatabase() {
var timeoutId;
this.setState({isSaved: false});
if (timeoutId) {
clearTimeout(timeoutId)
};
timeoutId = setTimeout( () => {
// Make ajax call to save data.
this.setState({isSaved: true});
}, 3000);
}
handleUserInput(e) {
const name = e.target.name;
const value = e.target.value;
this.setState({[name]: value});
this.saveToDatabase();
}
render() {
return (
<div>
{this.state.isSaved ? 'Saved' : 'Not saved'}
// My form.
</div>
)
}

Inside saveToDatabase method you are defining a new and undefined timeoutId variable every time the method is called. That's why the if statement never gets called.
Instead, you need to scope out the variable and create a class data property in the constructor.
constructor() {
super();
this.state = {
isSaved: false
};
this.timeoutId = null;
this.handleUserInput = this.handleUserInput.bind(this);
this.saveToDatabase = this.saveToDatabase.bind(this);
}
saveToDatabase() {
this.setState({isSaved: false});
if (this.timeoutId) {
clearTimeout(this.timeoutId)
};
this.timeoutId = setTimeout( () => {
// Make ajax call to save data.
this.setState({isSaved: true});
}, 3000);
}