Clean up link_generator notebook / app

binder/link_generator.ipynb

@@ -6,11 +6,13 @@
    "source": [
     "# Generate `nbgitpuller` links for your JupyterHub\n",
     "\n",
-    "Below is an interactive widget that lets you compose interact links\n",
-    "with `nbgitpuller`. In the form below, input your JupyterHub\n",
-    "URL as well as the repository\n",
-    "URL and information for the content you wish to share, and your interact\n",
-    "link will be printed below."
+    "When users click an `nbgitpuller` link pointing to your JupyterHub,\n",
+    "\n",
+    "1. They are asked to log in to the JupyterHub if they have not already\n",
+    "2. The git repository referred to in the nbgitpuller link is made up to date in their home directory (keeping local changes if there are merge conflicts)\n",
+    "3. They are shown the specific notebook / directory referred to in the nbgitpuller link.\n",
+    "\n",
+    "This is a great way to distribute materials to students."
    ]
   },
   {
@@ -20,21 +22,41 @@
    "outputs": [],
    "source": [
     "from ipywidgets import interact\n",
+    "from urllib.parse import urlunparse, urlparse, urlencode, parse_qs\n",
+    "from IPython.display import Markdown\n",
     "\n",
     "@interact\n",
-    "def make_nbgitpuller_link(hub_url='', repo_url='', branch='', subPath='', app=''):\n",
+    "def make_nbgitpuller_link(hub_url='', repo_url='', branch='', filepath='', app=['notebook', 'lab']):\n",
     "    \"\"\"Generate an ipywidget form that creates an interact link.\"\"\"\n",
-    "    hub_url = hub_url.strip()\n",
-    "    kwargs = {}\n",
-    "    for name, val in [('repo', repo_url), ('branch', branch), ('subPath', subPath), ('app', app)]:\n",
-    "        if len(val) > 1:\n",
-    "            kwargs[name] = val.strip()\n",
-    "    params = f'&'.join(['{}={}'.format(nm, val) for nm, val in kwargs.items()])\n",
-    "    url = f'{hub_url}/hub/user-redirect/git-pull?{params}'\n",
-    "    if len(app) > 0 and app.strip() not in ['notebook', 'lab']:\n",
-    "        print('app must be one of [\"notebook\", \"lab\"]')\n",
-    "    elif (len(hub_url) > 0) and (len(repo_url) > 0):\n",
-    "        print(url)"
+    "    \n",
+    "    # Don't do anything if we don't have a hub_url or repo_url\n",
+    "    if not (len(hub_url) > 0 and len(repo_url) > 0):\n",
+    "        return\n",
+    "    \n",
+    "    # Parse the query to its constituent parts\n",
+    "    \n",
+    "    scheme, netloc, path, params, query_str, fragment = urlparse(hub_url.strip())\n",
+    "    \n",
+    "    # nbgitpuller takes arguments via query parameters.\n",
+    "    # However, your hub might already require query parameters to function (for example, to pick a profile to launch in)\n",
+    "    # So we preserve the parameters we get & amend them to include the git-pull info we want\n",
+    "    query = parse_qs(query_str, keep_blank_values=True)\n",
+    "    \n",
+    "    \n",
+    "    # Make sure the path doesn't contain multiple slashes\n",
+    "    if not path.endswith('/'):\n",
+    "        path += '/'\n",
+    "    path += 'hub/user-redirect/git-pull'\n",
+    "    \n",
+    "    # Construct query parameters from \n",
+    "    for name, val in [('repo', repo_url), ('branch', branch), ('subPath', filepath), ('app', app)]:\n",
+    "        if len(val) > 0:\n",
+    "            query[name] = val.strip()\n",
+    "    \n",
+    "    url = urlunparse((scheme, netloc, path, params, urlencode(query, doseq=True), fragment))\n",
+    "    \n",
+    "    # FIXME: Have this return something instead of print so we can unit test\n",
+    "    print(url)"
    ]
   }
  ],