vue-axios-file-upload-example-feature-image

Vue File Upload example using Axios

In this tutorial, I will show you way to build a Vue File Upload example that uses Axios and Multipart File for making HTTP requests. You will also know how to add Bootstrap progress bar, show response message and display list of files’ information (with url).

More Practice:
Vue.js 2 CRUD Application with Vue Router & Axios
Vue.js JWT Authentication with Vuex and Vue Router
Vue Pagination with Axios and API example

Using Vuetify: Vuetify File Upload example


Overview

We’re gonna create a Vue File upload application in that user can:

  • see the upload process (percentage)
  • view all uploaded files
  • link to the file when clicking on the file name

vue-axios-file-upload-example-demo

Here are APIs that we will use Axios to make HTTP requests:

MethodsUrlsActions
POST/uploadupload a File
GET/filesget List of Files (name & url)
GET/files/[filename]download a File

You can find how to implement the Rest APIs Server at one of following posts:
Node.js Express File Upload Rest API example
Spring Boot Multipart File upload (to static folder) example

Or: Spring Boot Multipart File upload (to database) example

Technology

  • Vue 2.6
  • Axios 0.19.2
  • Bootstrap 4

Setup Vue File Upload Project

Open cmd at the folder you want to save Project folder, run command:
vue create vue-upload-files

You will see some options, choose default (babel, eslint).

Then we add Axios library with command: npm install axios.

Structure the Project

After the process is done. We create new folders and files like this:

vue-axios-file-upload-example-project-structure

UploadFilesService provides methods to save File and get Files using Axios.
UploadFiles component contains upload form, progress bar, display of list files.
App.vue is the container that we embed all Vue components.

index.html for importing the Bootstrap.
http-common.js initializes Axios with HTTP base Url and headers.
– We configure port for our App in vue.config.js

Add Bootstrap to the project

Open index.html and add following line into <head> tag:

<!DOCTYPE html>
<html lang="en">
  <head>
    ...
    <link type="text/css" rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css" />
  </head>
  ...
</html>

Initialize Axios for Vue HTTP Client

Under src folder, we create http-common.js file like this:

import axios from "axios";

export default axios.create({
  baseURL: "http://localhost:8080",
  headers: {
    "Content-type": "application/json"
  }
});

Remember to change the baseURL, it depends on REST APIs url that your Server configures.

Create Service for Upload Files

This service will use Axios to send HTTP requests.
There are 2 functions:

  • upload(file): POST form data with a callback for tracking upload progress
  • getFiles(): GET list of Files’ information

services/UploadFilesService.js

import http from "../http-common";

class UploadFilesService {
  upload(file, onUploadProgress) {
    let formData = new FormData();

    formData.append("file", file);

    return http.post("/upload", formData, {
      headers: {
        "Content-Type": "multipart/form-data"
      },
      onUploadProgress
    });
  }

  getFiles() {
    return http.get("/files");
  }
}

export default new UploadFilesService();

– First we import Axios as http from http-common.js.

FormData is a data structure that can be used to store key-value pairs. We use it to build an object which corresponds to an HTML form with append() method.

– We pass onUploadProgress to exposes progress events. This progress event are expensive (change detection for each event), so you should only use when you want to monitor it.

– We call the post() & get() method of Axios to send an HTTP POST & Get request to the File Upload server.

Create Component for Upload Files

Let’s create a File Upload UI with Progress Bar, Card, Button and Message.

First we create a Vue component template and import UploadFilesService:

components/UploadFiles.vue

<template>

</template>

<script>
import UploadService from "../services/UploadFilesService";

export default {
  name: "upload-files",
  data() {
    return {

    };
  },
  methods: {
  
  }
};
</script>

Then we define the some variables inside data()

export default {
  name: "upload-files",
  data() {
    return {
      selectedFiles: undefined,
      currentFile: undefined,
      progress: 0,
      message: "",

      fileInfos: []
    };
  },
};

Next we define selectFile() method which helps us to get the selected Files from ref="file" element in HTML template later.

export default {
  name: "upload-files",
  ...
  methods: {
    selectFile() {
      this.selectedFiles = this.$refs.file.files;
    }
  }
};

We also define upload() method for upload file:

export default {
  name: "upload-files",
  ...
  methods: {
    ...
    upload() {
      this.progress = 0;

      this.currentFile = this.selectedFiles.item(0);
      UploadService.upload(this.currentFile, event => {
        this.progress = Math.round((100 * event.loaded) / event.total);
      })
        .then(response => {
          this.message = response.data.message;
          return UploadService.getFiles();
        })
        .then(files => {
          this.fileInfos = files.data;
        })
        .catch(() => {
          this.progress = 0;
          this.message = "Could not upload the file!";
          this.currentFile = undefined;
        });

      this.selectedFiles = undefined;
    }
  }
};

We use selectedFiles for accessing current File as the first Item. Then we call UploadService.upload() method on the currentFile with a callback.

The progress will be calculated basing on event.loaded and event.total.
If the transmission is done, we call UploadService.getFiles() to get the files’ information and assign the result to fileInfos variable.

Here, fileInfos is an array of {name, url} objects.

We also need to do this work in mounted() method:

export default {
  name: "upload-files",
  ...
  mounted() {
    UploadService.getFiles().then(response => {
      this.fileInfos = response.data;
    });
  }
};

Now we implement the HTML template of the Upload File UI. Add the following content to <template>:

<template>
  <div>
    <div v-if="currentFile" class="progress">
      <div
        class="progress-bar progress-bar-info progress-bar-striped"
        role="progressbar"
        :aria-valuenow="progress"
        aria-valuemin="0"
        aria-valuemax="100"
        :style="{ width: progress + '%' }"
      >
        {{ progress }}%
      </div>
    </div>

    <label class="btn btn-default">
      <input type="file" ref="file" @change="selectFile" />
    </label>

    <button class="btn btn-success" :disabled="!selectedFiles" @click="upload">
      Upload
    </button>

    <div class="alert alert-light" role="alert">{{ message }}</div>

    <div class="card">
      <div class="card-header">List of Files</div>
      <ul class="list-group list-group-flush">
        <li
          class="list-group-item"
          v-for="(file, index) in fileInfos"
          :key="index"
        >
          <a :href="file.url">{{ file.name }}</a>
        </li>
      </ul>
    </div>
  </div>
</template>

In the code above, we use Bootstrap Progress Bar:

  • .progress as a wrapper
  • inner .progress-bar to indicate the progress
  • .progress-bar requires style to set the width by percentage
  • .progress-bar also requires role and some aria attributes to make it accessible
  • Labels to progress bar is the text within it

Add Upload File Component to App Component

Open App.vue and embed the UploadFiles Component with <upload-files> tag.

<template>
  <div id="app">
    <div class="container" style="width:600px">
      <div style="margin: 20px">
        <h3>bezkoder.com</h3>
        <h4>Vue.js upload Files</h4>
      </div>

      <upload-files></upload-files>
    </div>
  </div>
</template>

<script>
import UploadFiles from "./components/UploadFiles";

export default {
  name: "App",
  components: {
    UploadFiles
  }
};
</script>

Configure Port for Vue File Upload App

Because most of HTTP Server use CORS configuration that accepts resource sharing retricted to some sites or ports. And if you use the Project in this post for making Server, you need to configure port for our App.

In src folder, create vue.config.js file with following content:

module.exports = {
  devServer: {
    port: 8081
  }
}

We’ve set our app running at port 8081. vue.config.js will be automatically loaded by @vue/cli-service.

Run the App

Run this Vue File Upload App with command: npm run serve.

Open Browser with url http://localhost:8081/ and check the result.

Further Reading

Fullstack CRUD App:

Conclusion

Today we’re learned how to build an example for upload Files using Vue and Axios. We also provide the ability to show list of files, upload progress with Bootstrap, and to download file from the server.

You can find how to implement the Rest APIs Server at one of following posts:
Node.js Express File Upload Rest API example
Spring Boot Multipart File upload (to static folder) example

Or: Spring Boot Multipart File upload (to database) example

If you want to use Vuetify for File Upload, you can visit the tutorial:
Vuetify File Upload example

Source code

The source code for this Vue Client is uploaded to Github.

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