Adding Graphics to a React App with D3 — Circle Chart

Check out my books on Amazon at https://www.amazon.com/John-Au-Yeung/e/B08FT5NT62

Subscribe to my email list now at http://jauyeung.net/subscribe/

D3 lets us add graphics to a front-end web app easily.

Vue is a popular front end web framework.

They work great together. In this article, we’ll look at how to add graphics to a Vue app with D3.

Circle Chart

We can create a circle chart with D3 in our React app.

For example, we can write:

import React, { useEffect } from "react";
import * as d3 from "d3";

export default function App() {
  useEffect(() => {
    const width = 400;
    const height = 400;
    const data = [10, 28, 35];
    const colors = ["green", "lightblue", "yellow"];

    const svg = d3
      .select("body")
      .append("svg")
      .attr("width", width)
      .attr("height", height);

    const g = svg
      .selectAll("g")
      .data(data)
      .enter()
      .append("g")
      .attr("transform", function (d, i) {
        return "translate(0,0)";
      });

    g.append("circle")
      .attr("cx", function (d, i) {
        return i * 75 + 50;
      })
      .attr("cy", function (d, i) {
        return 75;
      })
      .attr("r", function (d) {
        return d * 1.5;
      })
      .attr("fill", function (d, i) {
        return colors[i];
      });

    g.append("text")
      .attr("x", function (d, i) {
        return i * 75 + 25;
      })
      .attr("y", 80)
      .attr("stroke", "teal")
      .attr("font-size", "10px")
      .attr("font-family", "sans-serif")
      .text((d) => {
        return d;
      });
  }, []);

  return (
    <div className="App">
      <div id="svgcontainer"></div>
    </div>
  );
}

We create the svg by selecting the body and then add the svg to it.

And we also set the width and height of the SVG.

This is done with:

const svg = d3
  .select("body")
  .append("svg")
  .attr("width", width)
  .attr("height", height);

Then we create the group with the data by writing:

const g = svg
  .selectAll("g")
  .data(data)
  .enter()
  .append("g")
  .attr("transform", function(d, i) {
    return "translate(0,0)";
  });

data has the data.

Next, we add the circles by writing:

g.append("circle")
  .attr("cx", function(d, i) {
    return i * 75 + 50;
  })
  .attr("cy", function(d, i) {
    return 75;
  })
  .attr("r", function(d) {
    return d * 1.5;
  })
  .attr("fill", function(d, i) {
    return colors[i];
  });

We add the cx and cy attributes by call attr .

r has the radius, and fill has the background color for each circle.

Then we add the text that goes with the circles by writing:

g.append("text")
  .attr("x", function(d, i) {
    return i * 75 + 25;
  })
  .attr("y", 80)
  .attr("stroke", "teal")
  .attr("font-size", "10px")
  .attr("font-family", "sans-serif")
  .text((d) => {
    return d;
  });

We call append with the 'text' argument.

And then we set the x and y attributes of the position of the text.

Then we set the color of the text with the stroke .

font-size has the font size and font-family has the font family.

The text method takes a callback that returns the text.

Conclusion

We can add a circle chart into our React app with D3 easily.

The post Adding Graphics to a React App with D3 — Circle Chart appeared first on The Web Dev.