How to correctly implement IGV.js with React?

Question

I am trying to implement IGV.js with React, and I found that the following code creates two container divs instead of one:

var igvDiv = document.getElementById("igv-div");
      var options =
        {
            genome: "hg38",
            locus: "chr8:127,736,588-127,739,371",
            tracks: [
                {
                    "name": "HG00103",
                    "url": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram",
                    "indexURL": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram.crai",
                    "format": "cram"
                }
            ]
        };

        igv.createBrowser(igvDiv, options)
                .then(function (browser) {
                    console.log("Created IGV browser");
                })

My react code is this better useing useRef:

import React, { useRef, useEffect, Component } from 'react';

import igv from 'igv';

var igvStyle = {
  fontFamily: 'open sans,helveticaneue,helvetica neue,Helvetica,Arial,sans-serif',
    paddingTop: '60px',
    margin: '5px'
  }
  class IGViewerSection extends Component {

    componentDidMount() {
      var igvContainer = document.getElementById('igv-div');
      var igvOptions = {
        genome: "hg38",
        locus: "chr8:127,736,588-127,739,371",
        tracks: [
            {
                "name": "HG00103",
                "url": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram",
                "indexURL": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram.crai",
                "format": "cram"
            }
        ]
    };
      return igv.createBrowser(igvContainer, igvOptions);
    }
  
    render() {
      return (
        <div id="igv-div" style={igvStyle}></div>
      );
    }
  }
  

export default IGViewerSection;

I would like to implement IGV.js with React using the correct approach. Could you please guide me on the correct way to implement IGV.js with React, and how to fix

Answer 1

Here is the correct version, you attach your ref object with the ref prop and you can use it when the component is mounted.

import React, { createRef, Component } from 'react';
import igv from 'igv';

const igvStyle = {
  fontFamily: 'open sans,helveticaneue,helvetica neue,Helvetica,Arial,sans-serif',
  paddingTop: '60px',
  margin: '5px'
}

class IGViewerSection extends Component {
  constructor(props) {
    super(props)
    this.container = createRef(null)
  }

  componentDidMount() {
    const igvOptions = {
      genome: "hg38",
      locus: "chr8:127,736,588-127,739,371",
      tracks: [
        {
          "name": "HG00103",
          "url": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram",
          "indexURL": "https://s3.amazonaws.com/1000genomes/data/HG00103/alignment/HG00103.alt_bwamem_GRCh38DH.20150718.GBR.low_coverage.cram.crai",
          "format": "cram"
        }
      ]
    };
    return igv.createBrowser(this.container.current, igvOptions);
  }

  render() {
    return (
      <div id="igv-div" ref={this.container} style={igvStyle}></div>
    );
  }
}
  

export default IGViewerSection;