I dont see the issue with the setInterval - forms

Question

In this code, I would like to clear the message after I successfully sent a message via the form I set up a setInterval but it does not work on the specified code but work when I try it in the console. log.
here is the code the component success-message have the message saying that the message has been sent successfully but won't update with the setInterval.
<template>
<success-message v-if="!successMessage" ></success-message>
<!-- <div v-show="successMessage"> -->
<form #submit.prevent="submitForm" >
<div class="form-control">
<label for='name'>Your Name</label>
<input type="name" id="name" v-model.trim="name"/>
</div>
<div class="form-control">
<label for='email'>Your email</label>
<input type="email" id="email" v-model.trim="email"/>
</div>
<div>
<label for='message'>Your message</label>
<textarea row="5" id="message" v-model.trim="message"></textarea>
</div>
<p class="errors" v-if="!formIsValid">Please you enter all requested informations.</p>
<div class="actions">
<button>Send Message</button>
</div>
</form>
<!-- </div> -->
</template>
<script>
export default {
data(){
return {
name: '',
email: '',
message: '',
successMessage: true,
formIsValid: true,
}
},
methods: {
submitForm(){
this.formIsValid = true;
if (this.name === '' || this.email === '' || !this.email.includes('#') || this.message === '') {
this.formIsValid = false;
return;
} else {
fetch("https://vue-http-demo-8aa03.firebaseio.com/stone.json", {
method: 'POST',
headers: {
'content-type': 'application/json'
},
body: JSON.stringify({name: this.name,
email: this.email,
message: this.message}),
}).then((data)=>{
if (data.status === 200) {
this.successMessage = false;
this.name ='';
this.email ='';
this.message ='';
setInterval(function(){ this.successMessage=true;}, 3000);
setInterval(function(){ console.log(this.successMessage=true);}, 3000);
}
});
}
},
},
}
</script>

Answer 1

If you want to access valid scope for this, you need to use arrow function for setInterval:
setInterval(() => {
this.successMessage = true;
}, 3000);