Javascript to export html table to Excel

Javascript to export html table to Excel

JSON to Excel for VUE 2

JSON to Excel for VUE 2

Download your JSON data as an excel file directly from the browser. This component it's based on the solution proposed on this thread https://stackoverflow.com/questions/17142427/javascript-to-export-html-table-to-excel

Important! Extra prompt in Microsoft Excel

The method implemented in this component use HTML tables to draw the .xls files, Microsoft Excel no longer recognize HTML as native content so will prompt a warning message before open the file. The content will be rendered perfectly but the message can't be avoid.

Getting started

Get the package:

npm install vue-json-excel

Register JsonExcel in your app entrypoint:

import Vue from 'vue'
import JsonExcel from 'vue-json-excel'

Vue.component('downloadExcel', JsonExcel)

In your template

<download-excel
    :data   = "json_data">
    Download Data
    <img src="download_icon.png">
</download-excel>

Props List

Name Type Description
data Array Data to be exported
fields Object fields inside the Json Object that you want to export. If no given, all the properties in the Json are exported
export-fields (exportFields) Object this prop is used to fix the problem with other components that use the variable fields, like vee-validate. exportFields works exactly like fields
type string mime type [xls, csv], default: xls
name string filename to export, deault: data.xls
title string/Array Title(s) for the data, could be a string or an array of strings (multiple titles)
footer string/Array Footer(s) for the data, could be a string or an array of strings (multiple footers)
default-value (defaultValue) string Use as fallback when the row has no field values, default: ''
worksheet string Name of the worksheet tab. default: 'Sheet1'
fetch Function Callback to fetch data before download, if it's set it runs immediately after mouse pressed and before download process. IMPORTANT: only works if no data prop is defined
before-generate Function Callback to call a method right before the generate / fetch data, eg:show loading progress
before-finish Function Callback to call a method right before the download box pops out, eg:hide loading progress

Example

import Vue from 'vue'
import JsonExcel from 'vue-json-excel'

Vue.component('downloadExcel', JsonExcel)

const app = new Vue({
    el: '#app',
    data: {
        json_fields: {
            'Complete name': 'name',
            'City': 'city',
            'Telephone': 'phone.mobile',
            'Telephone 2' : {
                field: 'phone.landline',
                callback: (value) => {
                    return `Landline Phone - ${value}`;
                }
            },
        },
        json_data: [
            {
                'name': 'Tony Peña',
                'city': 'New York',
                'country': 'United States',
                'birthdate': '1978-03-15',
                'phone': {
                    'mobile': '1-541-754-3010',
                    'landline': '(541) 754-3010'
                }
            },
            {
                'name': 'Thessaloniki',
                'city': 'Athens',
                'country': 'Greece',
                'birthdate': '1987-11-23',
                'phone': {
                    'mobile': '+1 855 275 5071',
                    'landline': '(2741) 2621-244'
                }
            }
        ],
        json_meta: [
            [
                {
                    'key': 'charset',
                    'value': 'utf-8'
                }
            ]
        ],
    }
})

In your HTML call it like

<download-excel
	class   = "btn btn-default"
	:data   = "json_data"
	:fields = "json_fields"
	worksheet = "My Worksheet"
	name    = "filename.xls">

	Download Excel (you can customize this with html code!)

</download-excel>

REQUIRED

  • json_data: Contains the data you want to export,
  • json_fields: You can select what fields to export, especify nested data and assign labels to the fields the key is the label, the value is the JSON field. This will export the field data 'as is'. If you need to customize the the exported data you can define a callback function. Thanks to @gucastiliao.
let json_fields = {
    // regular field (exported data 'as is')
    fieldLabel: attributeName, // nested attribute supported
    // callback function for data formatting
    anotherFieldLabel: {
        field: anotherAttributeName, // nested attribute supported
        callback: (value) => {
            return `formatted value ${value}`
        }
    },
}

Export CSV

To export JSON to CSV file just add the prop type with value "csv":

<download-excel
	class   = "btn btn-default"
	:data   = "json_data"
	:fields = "json_fields"
	type    = "csv"
	name    = "filename.xls">

	Download Excel (you can customize this with html code!)

</download-excel>

Multi-line values will appear in a single cell in Excel

A single text value in the data that contains newline characters will appear as a single cell in Excel. This avoids the undesired behavior of multi-line values getting split into multiple cells that must be merged before using data filters and pivot tables.

For example:

<template>
    <div>
        <json-excel :data="dataForExcel"></json-excel>
    </div>
</template>
<script>
import JsonExcel from "@/components/JsonExcel";

export default {
  components: {
    JsonExcel
  },
  data: () => {
    return {
      dataForExcel: [
        { colA: "Hello", colB: "World" },
        {
          colA: "Multi-line",
          /* Multi-line value: */
          colB:
            "This is a long paragraph\nwith multiple lines\nthat should show in a single cell."
        },
        { colA: "Another", colB: "Regular cell" }
      ]
    };
  }
};
</script>

Example of Excel showing multi-line cell

Fetch Data on Demand

In case you need to fetch data from the server, you could use the fetch prop that allows you to define a callback function that is executed when your user click the download button. This function has to return a json value containing the data to export. A basic use case is:

<template>
  <div id="app">
    
    <hr>
    <h2>Fetch Example</h2>
    <downloadexcel
      class = "btn"
      :fetch   = "fetchData"
      :fields = "json_fields"
      :before-generate = "startDownload"
      :before-finish = "finishDownload"
      type    = "csv">
      Download Excel
    </downloadexcel>
  </div>
</template>

<script>
import downloadexcel from "vue-json-excel";
import axios from 'axios';

export default {
  name: "App",
  components: {
    downloadexcel,
  },
  data(){
    return {
      json_fields: {
        'Complete name': 'name',
        'Date': 'date',
      },
    }
  }, //data
  methods:{
    async fetchData(){
      const response = await axios.get('https://holidayapi.com/v1/holidays?key=a4b2083b-1577-4acd-9408-6e529996b129&country=US&year=2017&month=09');
      console.log(response);
      return response.data.holidays;
    },
    startDownload(){
        alert('show loading');
    },
    finishDownload(){
        alert('hide loading');
    }
  }
};
</script>

Using callbacks

when using callbacks function in the fields description, you have three option to retrieve data:

  • field: 'path.to.nested.property' you can retrieve an especific value using the nested property notation.
    json_fields: {
        'Complete name': 'name',
        'City': 'city',
        'Telephone': 'phone.mobile',
        'Telephone 2' : {
            field: 'phone.landline',
            callback: (value) => {
                return `Landline Phone - ${value}`;
            }
        },
    },
  • field: 'define.nested.object' you can retrieve an nested object too
    json_fields: {
        'Complete name': 'name',
        'City': 'city',
        'Telephone': 'phone.mobile',
        'Telephone 2' : {
            field: 'phone',
            callback: (value) => {
                return `Landline Phone - ${value.landline}`;
            }
        },
    },
  • Or get the whole row if field it's undefined.
    json_fields: {
        'Complete name': 'name',
        'City': 'city',
        'Telephone': 'phone.mobile',
        'Telephone 2' : {
            callback: (value) => {
                return `Landline Phone - ${value.phone.landline}`;
            }
        },
    },

License

MIT

Status

This project is in an early stage of development. Any contribution is welcome :D

Github Repository

Tags: #VueJs #Json