CODEWITHSUNDEEP
reactjsecmascript-6jsxreact-rails
Santhosh
Santhosh

Reputation: 160

How to change the height of textarea with content?

I am trying to change the height of the textarea as per the content height. I see that the event handler doesn't change the height since it is getting overwritten by the bootstrap style. Please help!

class PostForm extends React.Component {
  constructor(props){
    super(props);
    this.state = {titleHeight: '30', storyHeight: 1};                                                    
    this.handleKeyUp = this.handleKeyUp.bind(this);
  }
  handleKeyUp(event){
    this.setState({titleHeight: document.getElementById('post_title').scrollHeight});
    this.setState({storyHeight: document.getElementById('post_story').scrollHeight});
  }
  render () {
        var csrfToken = $('meta[name=csrf-token]').attr('content');
        return (
          <form action='create' method='post' acceptCharset='UTF-8' className= "form-group">
            <input type='hidden' name='_method' value='patch'/>
            <input type='hidden' name='utf8' value='✓' />
            <input type='hidden' name='authenticity_token' value={csrfToken} />
            <textarea id="post_title" name="post[title]" className="form-control boldText" style={formStyle.textArea} height={this.state.titleHeight} onKeyUp={this.handleKeyUp} placeholder="Title"/>
            <textarea id="post_story" name="post[story]" className="form-control" style={formStyle.textArea} height={this.state.storyHeight} onKeyUp={this.handleKeyUp} placeholder="Start telling the story"/>
            <input name="commit" type="submit" value="Post" className="btn" style={formStyle.button}/>
          </form>
        );
  }
}

const formStyle = {
  textArea: {
    border: 5,
    boxShadow: 'none',
    margin: 5,
    overflow: 'hidden',
    resize: 'none',
    ariaHidden: 'true',
  },
  button: {
    backgroundColor: 'black',
    color: 'white',
    width: 70,
    marginLeft: 18,
    marginRight: 5,
  },
}

Upvotes: 9

Views: 31483

Answers (4)

Long Vuong
Long Vuong

Reputation: 181

For any newcomer, checkout react-textarea-autosize to see it it's what you need

Upvotes: -1

Arshdeep Singh
Arshdeep Singh

Reputation: 316

This code can change the textarea height even if it has some text initially, and even after on any change :)

export default class dynamicTextArea extends Component {
    constructor(props){
        super(props);

        this.textAreaRef = React.createRef();
    }

    componentDidMount() {
        this.textareaChange(this.textAreaRef.current);
    }

    textareaChange(ta) {
        ta.style.height = "auto";
        ta.style.height = ta.scrollHeight + "px";
    }

    render() {
        return(
            <textarea
                ref={this.textAreaRef}
                onChange={(e) => this.textAreaChange(e.target)}
            />
        );
    }
}

If you want to decrease the initial height even more then change:

ta.style.height = "auto";

to

ta.styel.height = "30px"; // better if equal to line-height

Upvotes: 1

user7103386
user7103386

Reputation:

You can do what you want with ref attribute

export default class Textarea extends Component {

  componentDidMount () {
    if (this.multilineTextarea) {
      this.multilineTextarea.style.height = 'auto';
    }
  }

  changeTextarea = () => {
    this.multilineTextarea.style.height = 'auto';
    this.multilineTextarea.style.height = this.multilineTextarea.scrollHeight + 'px';
  }

  render () {
    return (
      <textarea
        onChange={this.changeTextarea}
        ref={ref => this.multilineTextarea = ref}
      />
    );
  }
}

Also here is working DEMO

Upvotes: 5

JulienD
JulienD

Reputation: 7293

The textarea HTML component has no attribute height but an attribute rows that you can use for that purpose (e.g. <textarea rows={Math.round(this.state.storyHeight)} ... />).

No CSS style will override what you pass in the style attribute, it works the opposite way. But there is no height in your formStyle definition anyway.

Upvotes: 12

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