如何从 JupyterLab 扩展激活方法访问笔记本？

Question

前段时间我为 JupyterNotebook 编写了一个扩展。现在我想将其改编为 JupyterLab。为了访问当前打开的笔记本，我使用了：var notebook = Jupyter.notebook;var firstCell = notebook.get_cells()[0];=> Jupyterlab对应的代码是什么？module.exports = [{    id: 'jupyterlab_workspace_module',    autoStart: true,    activate: function(app) {       //app.notebook is not defined       var notebook = getNotebook(app); // <= how to implement this?    }}];

Answer 1

var notebookPanel = __getFirstVisibleNotebookPanel(app);

var notebook = notebookPanel.content;

var cell = notebook.activeCell;

function __getFirstVisibleNotebookPanel(app){

    var mainWidgets = app.shell.widgets('main');

    var widget = mainWidgets.next();

    while(widget){

        var type = widget.constructor.name;

        if(type == 'NotebookPanel'){  //other wigets might be of type DocumentWidget

            if (widget.isVisible){

                return widget;

            }

        }

        widget = mainWidgets.next();

    }

    return null;

}