How to load data from a CSV file in D3 v5

Question

I'm trying to load data from a CSV file in D3; I have this code:

function update (error, data) {     if (error !== null) {         alert ("Couldn't load the dataset!");     } else {         //do something     };  function changeData () {     d3.csv ("data/dataset.csv", update); } 

If I use D3 v4 it works fine, but if I switch to v5 it doesn't work anymore. Can someone explain to me how to modify the code to make it work with D3 v5?

Answer 1

d3 v5 uses the fetch API and returns a promise requiring the below code.

d3.csv('yourcsv.csv')   .then(function(data) {       // data is now whole data set       // draw chart in here!   })   .catch(function(error){      // handle error      }) 

In case in the future people want v4. d3 v4 on the other hand uses the XMLHttpRequest method, and does not return a promise requiring this code

d3.csv('yourcsv.csv', function(data) {     //whole data set     // draw chart here }) 

csv loading is async so make sure to run your chart code within the csv function.