d3.js - Importing local json file using d3.json does not work

Question

I try to import a local .json-file using d3.json().

The file filename.json is stored in the same folder as my html file.

Yet the (json)-parameter is null.

d3.json("filename.json", function(json) {
    root = json;
    root.x0 = h / 2;
    root.y0 = 0;});
    . . . 
}

My code is basically the same as in this d3.js example

Answer 1

If you're running in a browser, you cannot load local files.

But it's fairly easy to run a dev server, on the commandline, simply cd into the directory with your files, then:

python -m SimpleHTTPServer

(or python -m http.server using python 3)

Now in your browser, go to localhost:3000 (or :8000 or whatever is shown on the commandline).

---

The following used to work in older versions of d3:

var json = {"my": "json"};
d3.json(json, function(json) {
    root = json;
    root.x0 = h / 2;
    root.y0 = 0;
});