Holoviews rename issue

Broken Holoviews Example 1.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# This notebook reproduces a bug in Holoviews\n",
    "\n",
    "Renaming parameters in a stream using Stream.rename breaks the stream"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "import numpy as np\n",
    "%matplotlib inline"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import holoviews as hv\n",
    "from bokeh.io import output_notebook\n",
    "import param\n",
    "import parambokeh\n",
    "from holoviews.streams import Stream, Pipe, ParamValues, Tap, PointerX\n",
    "\n",
    "hv.notebook_extension('bokeh')\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "x = np.linspace(-2, 2, 100)\n",
    "x2 = x**2\n",
    "x3 = x**3"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# Show the data using a library that isn't the \"system under test\"\n",
    "df = pd.DataFrame({\"x\": x, \"x2\": x2, \"x3\": x3})\n",
    "df.plot()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "class ParamClass(Stream):\n",
    "    whichcurve = param.ObjectSelector(default=\"x3\", objects=df.columns)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "def simple_view(whichcurve):\n",
    "    \"\"\"\n",
    "    Generate a curve based on selected column\n",
    "    \"\"\"\n",
    "    plot_df = df.copy()\n",
    "    plot_df['y'] = plot_df[whichcurve]\n",
    "    plot_df = plot_df[[\"x\", \"y\"]]\n",
    "    \n",
    "    return hv.Curve(plot_df, \"x\", \"y\")\n",
    "\n",
    "def simple_view1(whichcurve1):\n",
    "    \"\"\"\n",
    "    Same as simple_view but with the argument renamed\n",
    "    \"\"\"\n",
    "    return simple_view(whichcurve=whichcurve1)\n",
    "\n",
    "\n",
    "def working_example():\n",
    "    param_instance = ParamClass()\n",
    "\n",
    "    parambokeh.Widgets(param_instance, continuous_update=True, callback=param_instance.event, on_init=True)\n",
    "    \n",
    "    return hv.DynamicMap(simple_view, streams=[param_instance])\n",
    "\n",
    "\n",
    "def broken_example():\n",
    "    param_instance = ParamClass()\n",
    "\n",
    "    parambokeh.Widgets(param_instance, continuous_update=True, callback=param_instance.event, on_init=True)\n",
    "    \n",
    "    # Renaming the stream parameter breaks the DynamicMap\n",
    "    return hv.DynamicMap(simple_view1, streams=[param_instance.rename(whichcurve=\"whichcurve1\")])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# This example lets you select which curve\n",
    "working_example()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "# In this example, selecting curve does not work\n",
    "#\n",
    "# Hard to see in a notebook, but in my bokeh app, when I use add_subscriber,\n",
    "# I can see that the renamed stream events do indeed get fired. However, my\n",
    "# graphs don't update.\n",
    "broken_example()"
   ]
  }
 ],
 "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
}