Visual Studio Code Jupyter Notebook Watcher Extension API Demo - V1

extension.js

const vscode = require('vscode');

function sleep(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}


async function handleNotebookKernel(api, uri, context) {
    let kernelFound = false;
    let kernel = undefined;
    // Wait until a kernel is running. This requires the user to run the kernel, having the notebook document open in the workspace is not enough
    while(!kernelFound) {
        // Get the kernel for the notebook document URI passed to the function
        kernel = await api.kernels.getKernel(uri);
        if (kernel !== undefined) {
            kernelFound = true;
        }
        await sleep(1000);
    }
 
 
    // Notebook is open and the kernel is running. Add logic to handle the kernel’s status change
    context.subscriptions.push(kernel.onDidChangeStatus((e) => {
       vscode.window.showInformationMessage(e);
    }));
}
 

async function notebookWatcher(context) {
    // Get Jupyter Extension public API implementation and make sure the extension is installed
    const jupyterExt = vscode.extensions.getExtension('ms-toolsai.jupyter');
    if (jupyterExt) {
        // Wait for the extension to go through its activation function
        const api = await jupyterExt.activate();
       
        let existingDocs = [];
        // Iterate forever and continue checking for new notebook documents in the workspace
        while(true) {
            for (const document of vscode.workspace.notebookDocuments) {
                if (!existingDocs.includes(document.uri)) {
                    // If we haven’t seen this notebook yet, pass it to a handler function
                    handleNotebookKernel(api, document.uri, context);
                    existingDocs.push(document.uri);
                }
            }
            await sleep(1000);
        }  
    }
}
 

/**
 * @param {vscode.ExtensionContext} context
 */
async function activate(context) {
	//start async Jupyter notebook watcher for when a user opens new notebooks
	notebookWatcher(context);
}


// This method is called when your extension is deactivated
function deactivate() {}


module.exports = {
	activate,
	deactivate
}

This is the v1 reference extension that monitors Jupyter Notebook kernels implemented by MeerkatIO to trigger notifications on cell executions.