Krdytkyu

Edit: if there's a better way to make this reproducible, please let me know. I can create some dummy data and put this in a codepen, but that wouldn't really reflect the interaction with React that's required.

I am going to need to build several React d3 components for a web application that I am building - I'd like to make sure the first one is done correctly before moving onto the next.

It is difficult to get a fully-working reproducable example, however here's the code for the full component (with my thoughts below):

Note: The component may seem long, but a lot of the code is simply getting the axis and grid drawn. In total i think it's a short component..

import React, { Component } from 'react';

import * as d3 from "d3";



class D3Scatter extends Component {



    // When component mounts, get

    componentDidMount() {

        const context = this.setContext();

        this.drawScatter(context);  

    }



    componentDidUpdate() {

        var context = d3.select(`#${this.props.svgID}`);

        context.remove();



        context = this.setContext();

        this.drawScatter(context);  

    }



    // This adds the SVG to the <div ref="scatter"> with some attrs

    setContext() {

        const { height, width, svgID } = this.props;

        return d3.select(this.refs.scatter).append('svg')

            .attr('id', svgID)

            .attr('width', '100%')

            .attr('height', '100%')

            .attr('viewBox', "0 0 " + width + " " + height)

            .attr('preserveAspectRatio', "xMaxYMax")



            .append('g')

            .attr('transform', `translate(25, 25)`);

    }



    // drawScatter called each time new props are passed

    drawScatter(context) {    

        const { 

            // data

            playerData,

            colorData,



            // formatting vals

            padding,

            margin, 

            height, 

            width,



            // chart parameters

            chartType,

            position,

            teamName, 

            playerName,

            xColname,

            yColname



        } = this.props;





        // Fit The Data to the SVG size and width

        var xScale = d3.scaleLinear()

            .domain(d3.extent(playerData, d => d[xColname]))

            .range([padding, width - padding])



        var yScale = d3.scaleLinear()

            .domain(d3.extent(playerData, d => d[yColname]))

            .range([height - padding, padding])



        var xAxis = d3.axisBottom(xScale)

            .tickSize(2*padding-height)

            .tickSizeOuter(0);



        var yAxis = d3.axisLeft(yScale)

            .tickSize(-width - 2*padding)

            .tickSizeOuter(0);





        // Size Scale for the markers

        // if a certain playerName or teamName is passed, change marker size

        var sizeScale = (player) => {

            // console.log("playerName:", playerName)

            // console.log("teamName:", teamName)

            if(player.playerFullName === playerName) {

                return "24px";

            } else if(player.teamName === teamName) {

                return "12px";

            } else {

                return "6px";

            }

        }



        // also change color for certain teamName or playerName passed

        var colorScale = (player) => {

            if(player.playerFullName === playerName) {

                var playersTeam = playerData

                    .filter(d => d.playerFullName === playerName)

                    .map(d => d.teamName)

                var thisColor = colorData

                    .filter(d => d.teamname === playersTeam)

                    .map(d => d.colorhex1)

                return thisColor;

            }

            else if(player.teamName === teamName) {

                var teamColor = colorData

                    .filter(d => d.teamname === teamName)

                    .map(d => d.colorhex1);

                return teamColor;

            } else {

                return '#DDD'; 

            }

        }



        // append the circles onto the page

        context

            .append('g')

            .selectAll("circle")

            .data(playerData)

            .enter()

            .append("circle")

                .attr("cx", d => xScale(d[xColname]))

                .attr("cy", d => yScale(d[yColname]))

                .attr("r", d => sizeScale(d))

                .attr("fill", d => colorScale(d))

                .attr("stroke", "#FFF")





        // Title, Y-Axis Name, X-Axis Name, Y-Axis Lines, X-Axis Lines

        context

            .append("text")

                .attr("x", width/2)

                .attr("y", padding)

                .attr("dy", "-1.5em")

                .style("text-anchor", "middle")

                .style("font-size", "2.5em") 

                .text(`Highlighting ${teamName} and ${playerName}!`)



        context

            .append("text")

                .attr("transform", "rotate(-90)")

                .attr("x", -height/2) // 

                .attr("y", padding)

                .attr("dy", "-2.5em") // gap from axis numbers

                .style("font-size", "1.5em") // axis name size

                .style("text-anchor", "middle")

                .text(`Player ${yColname}`)



        context

            .append("text")

                .attr("x", width/2)

                .attr("y", height - padding)

                .attr("dy", "2.5em")

                .style("font-size", "1.5em")

                .style("text-anchor", "middle")

                .text(`Player ${xColname}`)



        context

            .append("g")

                .attr("transform", "translate(0," + (height-padding) + ")")

                .call(xAxis);



        context

            .append("g")

            .attr("transform", "translate(" + padding + ",0)")

            .call(yAxis);



        return context

    }



    render() {



        const { gridID } = this.props;

        return (

            <div id={gridID} ref="scatter"></div>

        )

    }

}



export default D3Scatter;

There are a number of props passed to this component, which I've grouped into 3 different buckets:

1. 
   

   data props

   
   
   
   
   
   • 
     playerData: has all of the data that gets plotted
   
   
   • 
     colorData: has colors for each team (maps teamName to color)
   
   
   
   


2. 
   

   formatting props

   
   
   
   
   
   • 
     padding, margin, height, width all used for the SVG
   
   
   
   


3. 
   

   parent component state props (for filtering playerData)

   
   
   
   
   
   • 
     chartType: (not used here yet)
   
   
   • 
     position: (not used here yet)
   
   
   • `teamName: used for setting colors / sizes
   
   
   • 
     playerName: used for setting colors / sizes
   
   
   • 
     xColname: changes which key in playerData is used for x axis values
   
   
   • 
     yColname: changes which key in playerData is used for y axis values
   
   
   
   

My container app (the one that calls D3Scatter) has chartType, position, teamName, playerName, xColname and yColname in its state, and passes those down to D3Scatter depending on which buttons / select widgets are selected.

Eventually, I want to add transitions / animations so that when xColname and yColname are updated, the points slide to their new spots. I also plan on adding a tooltip and potentially other onClick effects, but I haven't done those yet. Currently I'm worried about whether I'm updating the chart right (if I'm using lifecycle components correctly), and other general best practices.

Last, an example of how this is called in its parent component:

<D3Scatter

    gridID="graph1"

    svgID={'d3-scatterplot'}

    playerData={playerSeasonData}

    colorData={mlbLogos}



    height={window.innerWidth*0.425}

    width={window.innerWidth*0.85}

    padding={50}

    margins={{top: 80, right: 35, bottom: 80, left: 25}}



    chartType={null}

    xColname={statNameX}

    yColname={statNameY}

    position={position}

    teamName={selectedTeam && selectedTeam.label}

    playerName={"Jay Bruce"} />

I've thought about the unholy union of D3 and React before, and I would be careful. I'd say that so far, your code looks fine, and if you know with a high degree of certainty you won't need much more than this, then you're fine.

However, I suspect you've only gotten started, and it's all the future improvements that will leave you banging your head (especially input handlers and animations).

I don't think the problem is that D3 doesn't like playing with React (although I know there are quirks), but rather that charts are a complex subject. They have their own abstract language, and most people aren't fluent.

You might consider using the new chart-parts. If you want a better foundation to build on, you might look at wrapping Vega in your own components. Or you might want to just see what else is out there: https://npms.io/search?q=react+charts.

Here's a great video with a deeper explanation of my warnings: The Missing Abstraction of Charting - Chris Trevino - React Conf 2018