CODEWITHSUNDEEP
javascriptreactjsscrollonscroll
Eunicorn
Eunicorn

Reputation: 621

React.js Call function after scroll event

I have built a React component which is suppose to call the function on window scroll event.

I would like to call the function, "getCards('default'), when the user scroll to 90% of the scroll height.

The component looks as shown in below:

class Home extends React.Component {

  constructor(props) {
    super(props);
    this.handleScroll = this.handleScroll.bind(this);
  }

  componentDidMount() {
    // test
    this.props.getCards('default');
    window.addEventListener('scroll', this.handleScroll);
  }

  handleScroll(event) {
    console.log('scroll event');
  }

Could anyone help me achieve this?

Thank you.

Upvotes: 4

Views: 11340

Answers (2)

monteirobrena
monteirobrena

Reputation: 2620

I've got a similar problem and nothing with onScroll work to me.

constructor(props) {
  super(props);
  window.addEventListener('scroll', this.handleScroll, true);
}

handleScroll = (event) =>  { 
  // Your code
}

https://gist.github.com/koistya/934a4e452b61017ad611

Upvotes: 1

Roberto Conte Rosito
Roberto Conte Rosito

Reputation: 2098

You have to work with your component, please refer to this code:

class Home extends React.Component {

  constructor(props) {
    super(props);
  }

  componentDidMount() {
    // test
    this.props.getCards('default');
  }

  render() {
    return (<div onScroll={this.handleScroll}>...</div>)
  }

  handleScroll(event) {
    var heightBound = window.height * 0.8
    if (heightBound > window.scrollY) {
        // Probably you want to load new cards?
        this.props.getCards(...);
    } 
  }

The scroll event must be placed inside your component and binded using onScroll evt. The handler will check for percentage of used screen size and will load others elements if the lower bound limit is reached.

I hope this can help :)

Upvotes: 4

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