Extension that executes shell or python code

Problem

I’d like to create an extension that runs some shell or python code. From what I’ve been able to find (mainly this: https://github.com/enlznep/jupyterlab-shell-file/blob/master/src/index.ts) and a failed attempt at using child_process or zx from the src/index.ts file I have not managed to execute any shell code from an extension. I am trying to replicate the toolbar button example but executing some shell code (could be python too - but ideally shell) when the button is clicked

Proposed Solution

I have also tried adding the following (to no success):

const { exec } = require("child_process");

exec("ls -la", (error, stdout, stderr) => {
    if (error) {
        console.log(`error: ${error.message}`);
        return;
    }
    if (stderr) {
        console.log(`stderr: ${stderr}`);
        return;
    }
    console.log(`stdout: ${stdout}`);
});

Any help is appreciated, also I’d love to see an example of this feature if it’s possible at all

[bollwyvl]

Where possible, you’ll want to use existing jupyterlab_server or jupyter_server REST API endpoints. These cover a lot of cases… indeed everything you see in JupyterLab!

To get really custom behavior, you’d extend the REST API with a python serverextension, and you can distribute both the static assets of the labextension and the handler in the same pip-installable package.

Of note: when the things you are calling are possible to be called directly from python, it can be useful to call them there, as you don’t have to worry as much about cross-platform concerns. nbconvert is such an example… but doesn’t have an asynchronous API. However, any time your code “blocks”, e.g. with subrocess.check_output it will block the whole system, and no other server methods will fire. For a while now, we’ve had anyio at our disposal, which has good support for cross-platform, async processes .

[luis-chaves-visa]

Hey @bollwyvl and @jasongrout, thanks for your replies!

After some digging I’ve gone down the server extension way. I still have some issues though, regarding how to get the current notebook path as @paugier is asking in #203. I’ll write another issue for clarity