NotebookApp.ipynb

NotebookApp.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Working Interactively with `NotebookApp`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from uuid import uuid4\n",
    "import logging\n",
    "from IPython.display import HTML, IFrame, SVG\n",
    "from notebook.notebookapp import NotebookApp, web\n",
    "from notebook.base.handlers import IPythonHandler\n",
    "import ipywidgets as W\n",
    "from tornado.httpclient import AsyncHTTPClient"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "PORT = 9999\n",
    "TOKEN = str(uuid4())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "app = NotebookApp()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## The Magic Moment"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "app.initialize([\"--port\", f\"{PORT}\", f\"--NotebookApp.token={TOKEN}\"])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "> You're going to want to collapse that output.\n",
    "\n",
    "It's actually a little anticlimactic: once `initialize`d, the app is _already_ listening, as the `IOLoop` is already running, and the server is already listening on `PORT`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "SVG(app.contents_manager.get(\"example.svg\")[\"content\"])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# A little bit about logging\n",
    "\n",
    "We'll explore more here later. Extracted from [this issue](https://github.com/jupyter-widgets/ipywidgets/issues/1936)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "class LogViewer(logging.Handler):\n",
    "    def __init__(self, output_widget, *args, **kwargs):\n",
    "        logging.Handler.__init__(self, *args)\n",
    "        for key, value in kwargs.items():\n",
    "            if f\"{key}\" == \"format\":\n",
    "                self.setFormatter(value)\n",
    "        self.output_widget = output_widget\n",
    "\n",
    "    def emit(self, record):\n",
    "        w = self.output_widget\n",
    "        msg = self.format(record)\n",
    "        w.outputs = (dict(name=\"stdout\", output_type=\"stream\", text=f\"{msg}\\n\"),) + w.outputs"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "output = W.Output()\n",
    "app.log.addHandler(LogViewer(output))\n",
    "output"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Dynamically Adding a (Dyanmic) Handler"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "bar = W.IntSlider(99, description=\"bar\")\n",
    "bar"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "class Bar(IPythonHandler):\n",
    "    re = r\"^/foo/?$\"\n",
    "    @web.authenticated\n",
    "    def get(self):\n",
    "        self.finish(\"🍻\" * bar.value)\n",
    "app.web_app.add_handlers('.*', [[Bar.re, Bar]])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Use the right client"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fetch = AsyncHTTPClient().fetch"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Using a synchronous client, like vanilla `requests`, or the `!curl` magic, will deadlock your kernel (and app!)."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "(\n",
    "    await fetch(f\"http://localhost:{PORT}/foo/?token={TOKEN}\")\n",
    ").body.decode(\"utf-8\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "bar.value = 1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "(\n",
    "    await fetch(f\"http://localhost:{PORT}/foo/?token={TOKEN}\")\n",
    ").body.decode(\"utf-8\")"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.7.3"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}