Vue.js - Write JSON object to local file

This is how I edit JSON files in my Vue projects. In this case, if you run the file, it will create a new data.json file and add Price to each JSON object:

const fs = require("fs");

let cars = [
  {
    Name: "chevrolet chevelle malibu",
    Miles_per_Gallon: 18,
    Cylinders: 8,
    Displacement: 307,
    Horsepower: 130,
    Weight_in_lbs: 3504,
    Acceleration: 12,
    Year: "1970-01-01",
    Origin: "USA"
  },
  {
    Name: "buick skylark 320",
    Miles_per_Gallon: 15,
    Cylinders: 8,
    Displacement: 350,
    Horsepower: 165,
    Weight_in_lbs: 3693,
    Acceleration: 11.5,
    Year: "1970-01-01",
    Origin: "USA"
  }
];
cars.forEach(car => {
  car.price = 12000;
});

let data = JSON.stringify(cars);
fs.writeFileSync("data.json", data);

There are 3 ways to do this.

  1. Write to local storage

  2. Create a Blob and invoke an event to download it

  3. Wrap it into a electron app and use node fs module to save file

I can show you a sample here for these 3 cases

index.html

<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Vue test</title>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/vue.js"></script>
</head>
<body>
<div id="vue-app">
    <form>
        <input type="text" v-model="name"/>{{name}}<br/>
        <input type="text" v-model="last"/>{{last}}<br/>
        <input type="text" v-model="index"/>{{index}}<br/>
        <select v-model="grade">
            <option>5</option>
            <option>6</option>
            <option>7</option>
            <option>8</option>
            <option>9</option>
            <option>10</option>
        </select>
        {{grade}}
        <button type="button" v-on:click="add()">Add To Table</button>
        <button type="button" v-on:click="saveFile()">saveFile</button>
    </form>
    <table border="1">
        <thead><td>Name</td><td>Last Name</td><td>Index</td><td>Grade</td></thead>
        <tbody>
        <tr v-for="x in arr">
            <td>{{x.first}}</td>
            <td>{{x.lastn}}</td>
            <td>{{x.index}}</td>
            <td>{{x.grade}}</td>
        </tr>
        </tbody>
    </table>
</div>
<script src="test.js"></script>
</body>
</html>

test.js (Write to local storage)

new Vue ({
  el: '#vue-app',
  data: {
      name: '',
      last: '',
      index: 0,
      grade: 0,
      arr: []
  },

  methods: {
      add: function (e) {
          this.arr.push({first: this.name, lastn: this.last, index: this.index, grade: this.grade});
          console.log(1);
      },
      saveFile: function() {
        const data = JSON.stringify(this.arr)
        window.localStorage.setItem('arr', data);
        console.log(JSON.parse(window.localStorage.getItem('arr')))
  }
});

Create a Blob and invoke a event to download it

only change for saveFile func

saveFile: function() {
    const data = JSON.stringify(this.arr)
    const blob = new Blob([data], {type: 'text/plain'})
    const e = document.createEvent('MouseEvents'),
    a = document.createElement('a');
    a.download = "test.json";
    a.href = window.URL.createObjectURL(blob);
    a.dataset.downloadurl = ['text/json', a.download, a.href].join(':');
    e.initEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    a.dispatchEvent(e);
}

Wrap it into an Electron app and use node fs module to save file

Change for saveFile func

saveFile: function() {
    const data = JSON.stringify(this.arr)
    const fs = require('fs');
    try { fs.writeFileSync('myfile.txt', data, 'utf-8'); }
    catch(e) { alert('Failed to save the file !'); }
}

Then use Electron to wrap it

electron ./index.html

Tags:

Javascript

Json

Node.Js

Vue.Js

Vuejs2

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