{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Custom Callbacks\n",
    "\n",
    "## Configuration"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib widget\n",
    "import matplotlib.pyplot as plt\n",
    "\n",
    "# Make plots live-update while scans run.\n",
    "from bluesky.utils import install_nb_kicker\n",
    "install_nb_kicker()\n",
    "\n",
    "import numpy as np\n",
    "from bluesky import RunEngine\n",
    "from bluesky.plans import scan\n",
    "from bluesky.examples import motor, noisy_det\n",
    "\n",
    "RE = RunEngine({})"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Data Acquisition\n",
    "\n",
    "### Simple Custom Callbacks"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# No callbacks\n",
    "RE(scan([noisy_det], motor, 1, 5, 5))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Print the type of document as each one is emitted.\n",
    "\n",
    "def cb(name, doc):\n",
    "    print(name)\n",
    "\n",
    "RE(scan([noisy_det], motor, 1, 5, 5), cb)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Print the event documents as they are emitted.\n",
    "\n",
    "def cb(name, doc):\n",
    "    if name == 'event':\n",
    "        print(doc)\n",
    "\n",
    "RE(scan([noisy_det], motor, 1, 5, 5), cb)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Make a simple table with sequence number, motor setpoint, and detector reading.\n",
    "\n",
    "def cb(name, doc):\n",
    "    if name == 'event':\n",
    "        print(doc['seq_num'], doc['data']['motor_setpoint'], doc['data']['noisy_det'])\n",
    "\n",
    "RE(scan([noisy_det], motor, 1, 5, 5), cb)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Compute the duration between the 'start' document and the 'stop' document.\n",
    "# Version 1 -- using a global variable (simple, but not recommended)\n",
    "\n",
    "start_time = None\n",
    "\n",
    "def cb(name, doc):\n",
    "    global start_time\n",
    "    if name == 'start':\n",
    "        start_time = doc['time']\n",
    "    if name == 'stop':\n",
    "        stop_time = doc['time']\n",
    "        duration = stop_time - start_time\n",
    "        print('Duration:', duration, 'seconds')\n",
    "\n",
    "RE(scan([noisy_det], motor, 1, 5, 5), cb)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Compute the duration between the 'start' document and the 'stop' document.\n",
    "# Version 2 -- using a class variable (recommended)\n",
    "\n",
    "from bluesky.callbacks import CallbackBase\n",
    "\n",
    "\n",
    "class Timer(CallbackBase):\n",
    "    def start(self, doc):\n",
    "        self.start_time = doc['time']\n",
    "    def stop(self, doc):\n",
    "        stop_time = doc['time']\n",
    "        duration = stop_time - self.start_time\n",
    "        print('Duration:', duration, 'seconds')\n",
    "\n",
    "RE(scan([noisy_det], motor, 1, 5, 5), Timer())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Binding Callbacks to Plans"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from bluesky.preprocessors import subs_decorator\n",
    "\n",
    "\n",
    "@subs_decorator(cb)\n",
    "def my_scan(detectors, motor, start, stop, num):\n",
    "    yield from scan(detectors, motor, start, stop, num)\n",
    "\n",
    "RE(my_scan([noisy_det], motor, 1, 5, 5))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# A useful pattern: Pass positional and keyword arguments through, blindly.\n",
    "\n",
    "@subs_decorator(cb)\n",
    "def my_scan(*args, **kwargs):\n",
    "    yield from scan(*args, **kwargs)\n",
    "\n",
    "RE(my_scan([noisy_det], motor, 1, 5, 5))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Exercises\n",
    "\n",
    "1. Write a custom callback that prints the detector reading divided by the motor position.\n",
    "2. Use `subs_decorator` to bind it to a custom variant of the `scan` plan.\n",
    "3. Write a custom callback that prints the contents of the start document. Then, if you can, make the output more readable by put each key/value pair on its own line."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "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": "3.6.6"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}