CODEWITHSUNDEEP
javascriptreactjs
fluorspar
fluorspar

Reputation: 227

TypeError: Cannot read property 'contentWindow' of undefined

I am trying to make a rich text editor using React.js and I am using iframe with the designMode property set to 'ON'. I want to make the selected text bold on click of a button. I want to use the execCommand() function but I keep getting this error: TypeError: Cannot read property 'contentWindow' of undefined. I am a beginner in React and I'm unable to figure out how to tackle this problem.

I've attached my code for your reference.

import React, { Component } from 'react'
import 'font-awesome/css/font-awesome.css'


export default class Editor extends Component {

    constructor(){
        super()
        this.execComd = this.execComd.bind(this)
    }

    componentDidMount(){
       let editor = this.textField.contentWindow.document
       editor.designMode = 'on'
    }

    execComd(command){
        this.textField.contentWindow.execCommand(command, false, null)   
    }

    render() {
        return (
            <> 
                <div>
                    <button onClick={this.execComd('bold')}><i className="fa fa-bold"></i></button>
                </div>
                <iframe 
                    ref={textField => this.textField = textField} 
                    id="textField" 
                    name="textField" 
                    style={{width: "1000px",height: "500px"}} 
                    frameborder="1">
                </iframe>
            </>
        )
    }
}

Upvotes: 5

Views: 18629

Answers (1)

Asutosh
Asutosh

Reputation: 1828

You have to create a ref binded ti this,. Such as this.myRef = React.createRef(), inside the constructor. Then assign that in the render method.

ref={this.myRef}

Inside escCommand you can have now:

execComd(command){
       this.myRef.current.contentWindow.execCommand(command, false, null)   
    }

To create a working demo of my proposal, please ignore as I have removed few unwanted code which i am not aware:

import React, { Component } from 'react'


export default class Editor extends Component {

    constructor(){
        super()
        this.execComd = this.execComd.bind(this)
        this.myRef=React.createRef();
    }

    componentDidMount(){
      
    }

    execComd(command){
      console.log("fired");
      console.log(this.myRef.current.contentWindow);
    
    }

    render() {
        return (
            <> 
                <div>
                    <button onClick={()=>this.execComd('bold')}>Click<i className="fa fa-bold"></i></button>
                </div>
                <iframe 
                    ref={this.myRef} 
                    title="hello"
                    id="textField" 
                    name="textField" 
                    style={{width: "1000px",height: "500px"}} 
                    frameborder="1">
                </iframe>
            </>
        )
    }
}

Upvotes: 2

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