Vue Js - Sending axios request after file input changes

Question

EDIT

This answer does solve a problem on running two different functions back to back. Nevertheless, my question deals specifically with the behavior of a file handling input and the moment in which to chain a second event (solved by the second example in @Igor 's answer).

QUESTION

I have a file upload Vue component which works perfectly fine. The improvement I would like to make is for it to work on "one click", meaning the upload() method should be triggered in response to the createImage() finishing. How would I do that?

<template>
<div>
    <div>
        <label>Image:</label>
        <img :src="(image) ? image : tempImage" class="img-fluid">
        <div class="custom-file">
            <input type="file" v-on:change="onFileChange" class="custom-file-input"
            :class="{ 'border-0':image }">
            <label class="custom-file-label" for="customFile">
                {{ filename ? filename : 'Choose pic' }}
            </label>
        </div>
    </div>
    <div>
        <button class="btn btn-success btn-block" 
        :disabled="!image"
        @click.prevent="upload">
            Upload
        </button>
    </div>
</div>
</template>
<script>
    export default{
        props: ['tempImage'],
        data(){
            return {
                image: '',
                filename: ''
            }
        },
        methods: {
            onFileChange(e) {
                let files = e.target.files || e.dataTransfer.files;
                this.$parent.uploading = true;
                if (!files.length)
                    return;
                this.createImage(files[0]);
            },
            createImage(file) {
                let reader = new FileReader();
                let vm = this;
                reader.onload = (e) => {
                    vm.image = e.target.result;
                };
                reader.readAsDataURL(file);
                vm.filename = file.name;
            },
            upload(){
                console.log(this.image);
                axios.post('/api/upload',{image: this.image}).then(res => {
                    if( !res.data.errors ){
                       this.$parent.tempData.image = res.data.src;
                       this.$parent.uploading = false;
                    } else {
                        console.log(res.data.errors);
                    }
                });
            }
        }
    }
</script>

Answer 1

What about calling upload() from createImage() ?

createImage(file) {
  let reader = new FileReader();
  let vm = this;
  reader.onload = (e) => {
    vm.image = e.target.result;
    vm.filename = file.name;
    this.upload();
  };
  reader.readAsDataURL(file);
}

Or passing upload() as a callback:

onFileChange(e) {
  let files = e.target.files || e.dataTransfer.files;
  this.$parent.uploading = true;
  if (!files.length)
    return;
  this.createImage(files[0], this.upload);
},
createImage(file, callback) {
  let reader = new FileReader();
  let vm = this;
  reader.onload = (e) => {
    vm.image = e.target.result;
    vm.filename = file.name;
    if (callback) callback();
  };
  reader.readAsDataURL(file);
}

Fiddle

Answer 2

You start off by creating a variable isUploading with an initial value of false . Then in your method upload you first check if the isUploading variable is false, if it is false , start upload , otherwise, either do nothing or inform the user that the page is still uploading image.

The code could look like this:

 var isUploading = false; export default { // ... upload() { // If not uploading anything start the upload if (!isUploading) { isUploading = true; console.log(this.image); axios.post('/api/upload', { image: this.image }).then(res => { if (!res.data.errors) { this.$parent.tempData.image = res.data.src; this.$parent.uploading = false; } else { console.log(res.data.errors); } }); } else { // Do other stuff here } } // ... }