How to include external javascript library in reac

问题:

I would like to know how it's possible to include an external javascript library in a react project. For exemple, I would like to import the jspdf library : https://github.com/MrRio/jsPDF/blob/master/jspdf.js and use it in my reactjs app.

So far I tried to use require like this : 

let React = require('react');
let { Spacing, Typography } = Styles;
let DoughnutChart = require("react-chartjs").Doughnut;
let Chart = require('react-google-charts').Chart;
let { StylePropable, StyleResizable } = Mixins;
let EditableDiv = require('../EditableDiv.jsx');
//some other library
//the library that matter for me
var pdfConverter = require('../utils/jspdf.source.js');

//then I have my classical react code which works and a function to generate ad pdf
_generatePdf: function(){
    console.log('Genrating pdf');
    var doc = new pdfConverter.jsPDF('p','pt');
    var img = new Image();
}

I have the following error : TypeError: pdfConverter.jsPDF is not a function.

To make it work, I made something ugly, I copy the source of jspdf-source.js into my react.jsx file and just call jsPDF instead of pdfConverter.jsPDF. It's definitly no the right way, but can't succed to import and use the library.

Can you tell me what I'm doing wrong and how I can correct this? Thank you

-EDIT-

When I was using my ugly solution (copying the source into my file) I just had to do the following :

var doc = new jsPDF('p','pt);

And it was working perfectly, expect that I had a very big file

After the suggested solution from @dannyjolie bellow, I've imported jspdf directly from the npm package, but I'm still not able to use the library. I tried the following code wich lead to an error:

var pdfConverter = require('jspdf');
var converter = new pdfConverter();
var doc = converter.jsPDF('p', 'pt');

TypeError: pdfConverter is not a constructor Meaning that I have to import the jsPDF coming from the package, not only jspdf ?

Then I try

let pdfConverter = require('jspdf');
var converter = pdfConverter.jsPDF;
var doc = new converter('p', 'pt');

ReferenceError: jsPDF is not defined

TypeError: converter is not a constructor

Ok obviously, I'm not importing the right thing or not the right way. What I'm doing wrong ?

回答1:

First of all, don't use the source file. Just npm install jspdf --save like any other package, and import it with var pdfConverter = require('jspdf');

Secondly, you're missing a () in this line var doc = new pdfConverter.jsPDF('p','pt');

Do something like this:

var converter = new pdfConverter();
var doc = converter.jsPDF('p', 'pt');

回答2:

If you include the external js file link in your /public/index.html, you can use the external library with the window prefix.

Take JQuery as an example. Put the following line in your /public/index.html:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>

Use it in your project like so:

window.$("#btn1").click(function(){
  alert("Text: " + $("#test").text());
});

回答3:

I know this is old, but I thought it would be helpful if someone posted a full working sample. It took me a while to figure this out, using this other post as a starting point:

How to make PDF from React?

Assuming you are using create-react-app, overwrite your App.js with the following below...

import React, { Component } from 'react';
import pdfConverter from 'jspdf';
import logo from './logo.svg';
import './App.css';

class App extends Component {
  constructor(props) {
    super(props);
    this.onClick = this.onClick.bind(this);
    this.toDataUrl = this.toDataUrl.bind(this);
  }

  toDataUrl(url, callback) {
    var xhr = new XMLHttpRequest();
    xhr.onload = function() {
      var reader = new FileReader();
      reader.onloadend = function() {
        callback(reader.result);
      }
      reader.readAsDataURL(xhr.response);
    };
    xhr.open('GET', url);
    xhr.responseType = 'blob';
    xhr.send();
  }

  onClick() {
      var doc = new pdfConverter('p','pt','letter');
      //console.log(doc.getFontList() );
      this.toDataUrl('background.jpg', function(base64Img) {
        var imgData = base64Img;
        console.log(imgData);
        console.log('Adding to doc.');
        doc.addImage(imgData, 'JPEG', 0, 0, 612, 792);
        console.log('Image added.');
        doc.setFont('Times', 'Roman');
        doc.setFontSize(22);
        doc.text(20, 50, 'Park Entry Ticket');
        doc.setFontSize(16);
        doc.text(20, 80, 'Address1: ' );
        doc.text(20, 100, 'Address2: ' );
        doc.text(20, 120, 'Entry Date & time: ');
        doc.text(20, 140, 'Expiry date & time: ' );
        console.log('About to save');
        doc.save("test.pdf");
      });
  }

  render() {
    return (
      <div className="App">
        <div className="App-header">
          <img src={logo} className="App-logo" alt="logo" />
          <h2>Welcome to React</h2>
        </div>
        <p className="App-intro">
          To get started, edit <code>src/App.js</code> and save to reload.
            <input type='button'
        onClick={this.onClick} value="Print"/>
        </p>
      </div>
    );
  }
}

export default App;