REACT: Can´t pass parameter to a lifting up event handler

Question

I can´t pass the parameters from a child component to a parent component using the same event handler.

My components' tree follows this structure:

• ProductList
  • ProductsGrid
  • PaginationBar

In the ProducList component I have this event handler

handlePagination = (index) => { bla bla bla }

<PaginationBar
  OnPagination={(index) => this.handlePagination(index)}
  pages={this.state.pages}
/>

In the Pagination Bar when I render the page.

  render() {
    return (
      <nav aria-label="Catalog page navigation">
        <ul className="pagination">
          <li className={this.navButtonEnabled(0)} key="page-item-0">
            <a
              className="page-link"
              onClick={this.props.OnPagination(0)}
              href="#"
              aria-label="Previous"
            >
              <span aria-hidden="true">Previous 3</span>
            </a>
          </li>
          <li className={this.navButtonEnabled(1)} key="page-item-1">
            <a
              className="page-link"
              onClick={this.props.OnPagination(1)}
              href="#"
            >
              <span aria-hidden="true">
                {this.navButtonDisplay(this.props.pages.navigation[1])}
              </span>
            </a>
          </li>
          <li className={this.navButtonEnabled(2)} key="page-item-2">
            <a
              className="page-link"
              onClick={this.props.OnPagination(2)}
              href="#"
            >
              <span aria-hidden="true">
                {this.navButtonDisplay(this.props.pages.navigation[2])}
              </span>
            </a>
          </li>
          <li className={this.navButtonEnabled(3)} key="page-item-3">
            <a
              className="page-link"
              onClick={this.props.OnPagination(3)}
              href="#"
            >
              <span aria-hidden="true">
                {this.navButtonDisplay(this.props.pages.navigation[3])}
              </span>
            </a>
          </li>
          <li className={this.navButtonEnabled(4)} key="page-item-4">
            <a
              className="page-link"
              onClick={this.props.OnPagination(4)}
              href="#"
              aria-label="Next"
            >
              <span aria-hidden="true">Next 3</span>
            </a>
          </li>
        </ul>
      </nav>
    );
  }
}

In the onClick event, I call the event handler with the index number (this is the parameter I want to pass), according the button clicked I render correctly the ProductsGrid. But it doesn't work at all, I tried several approaches, I just want to pass a number via a parameter for a lifting up event handler. What am I doing wrong?

This is the error presented in the console.

react_devtools_backend.js:6 Warning: Cannot update during an existing state transition (such as within render). Render methods should be a pure function of props and state. in Pagination (created by Catalog) in Catalog (created by App) in main (created by App) in App

I am not changing any state during the render process, the event handler changes the status, when the button is clicked. This is not a render process.

Answer 1

Please replace

onClick={this.props.OnPagination(0)}

With

onClick={() => {this.props.OnPagination(0)}}

Here is complete code (I have commented some code so that I can run this easily to my end):

import React from "react";

export default class ProductList extends React.Component {
    handlePagination = (index) => {
        console.log(index, 'index');
    };

    render() {
        return (
            <PaginationBar OnPagination={(index) => this.handlePagination(index)}
                // pages={this.state.pages}
            />
        );
    }
}

class PaginationBar extends React.Component {
    render() {
        return (
            <nav aria-label="Catalog page navigation">
                <ul className="pagination">
                    <li key="page-item-0">
                        <a
                            className="page-link"
                            onClick={() => {this.props.OnPagination(0)}}
                            href="#"
                            aria-label="Previous"
                        >
                            <span aria-hidden="true">Previous 3</span>
                        </a>
                    </li>
                    <li key="page-item-1">
                        <a
                            className="page-link"
                            onClick={() => {this.props.OnPagination(1)}}
                            href="#"
                        >
              <span aria-hidden="true">
                {/*{this.navButtonDisplay(this.props.pages.navigation[1])}*/}
                Previous 2
              </span>
                        </a>
                    </li>
                    <li key="page-item-2">
                        <a
                            className="page-link"
                            onClick={() => {this.props.OnPagination(2)}}
                            href="#"
                        >
              <span aria-hidden="true">
                {/*{this.navButtonDisplay(this.props.pages.navigation[2])}*/}
                Previous 1
              </span>
                        </a>
                    </li>
                    <li key="page-item-3">
                        <a
                            className="page-link"
                            onClick={() => {this.props.OnPagination(3)}}
                            href="#"
                        >
              <span aria-hidden="true">
                {/*{this.navButtonDisplay(this.props.pages.navigation[3])}*/}
                Next 2
              </span>
                        </a>
                    </li>
                    <li key="page-item-4">
                        <a
                            className="page-link"
                            onClick={() => {this.props.OnPagination(4)}}
                            href="#"
                            aria-label="Next"
                        >
                            <span aria-hidden="true">Next 3</span>
                        </a>
                    </li>
                </ul>
            </nav>
        );
    }
}