options_form is a regular configurable

now that we can assume User.spawner exists at all times

jupyterhub/handlers/base.py

@@ -452,12 +452,12 @@ class UserSpawnHandler(BaseHandler):
                 # spawn has supposedly finished, check on the status
                 status = yield current_user.spawner.poll()
                 if status is not None:
-                    if self.spawner_class.options_form:
+                    if current_user.spawner.options_form:
                         self.redirect(url_path_join(self.hub.server.base_url, 'spawn'))
                     else:
                         yield self.spawn_single_user(current_user)
             else:
-                if self.spawner_class.options_form:
+                if current_user.spawner.options_form:
                     self.redirect(url_path_join(self.hub.server.base_url, 'spawn'))
                 else:
                     yield self.spawn_single_user(current_user)

jupyterhub/handlers/login.py

@@ -68,7 +68,7 @@ class LoginHandler(BaseHandler):
             if user.spawner:
                 status = yield user.spawner.poll()
                 already_running = (status == None)
-            if not already_running and not self.spawner_class.options_form:
+            if not already_running and not user.spawner.options_form:
                 yield self.spawn_single_user(user)
             self.set_login_cookie(user)
             next_url = self.get_argument('next', default='')

jupyterhub/handlers/pages.py

@@ -63,10 +63,10 @@ class SpawnHandler(BaseHandler):
             self.log.debug("User is running: %s", url)
             self.redirect(url)
             return
-        if self.spawner_class.options_form:
+        if user.spawner.options_form:
             html = self.render_template('spawn.html',
                 user=self.get_current_user(),
-                spawner_options_form=self.spawner_class.options_form,
+                spawner_options_form=user.spawner.options_form,
             )
             self.finish(html)
         else:
@@ -87,7 +87,7 @@ class SpawnHandler(BaseHandler):
         form_options = {}
         for key, byte_list in self.request.body_arguments.items():
             form_options[key] = [ bs.decode('utf8') for bs in byte_list ]
-        options = self.spawner_class.options_from_form(form_options)
+        options = user.spawner.options_from_form(form_options)
         yield self.spawn_single_user(user, options=options)
         url = user.server.base_url
         self.redirect(url)

jupyterhub/spawner.py

@@ -73,24 +73,33 @@ class Spawner(LoggingConfigurable):
         help="Enable debug-logging of the single-user server"
     )
     
-    # options_form is a class attribute, defining an HTML form snippet,
-    # which can be used to specify whether
-    # (i.e. just the <input> elements, not submit button or the <form> tag).
-    # This is **not** a configurable, 
-    options_form = ""
-    @classmethod
-    def options_from_form(cls, form_data):
+    options_form = Unicode("", config=True, help="""
+        An HTML form for options a user can specify on launching their server.
+        The surrounding `<form>` element and the submit button are already provided.
+        
+        For example:
+        
+            Set your key:
+            <input name="key" val="default_key"></input>
+            <br>
+            Choose a letter:
+            <select name="letter" multiple="true">
+              <option value="A">The letter A</option>
+              <option value="B">The letter B</option>
+            </select>
+    """)
+
+    def options_from_form(self, form_data):
         """Interpret HTTP form data
         
         Form data will always arrive as a dict of lists of strings.
         Override this function to understand single-values, numbers, etc.
         
-        This should coerce form data into the structure expected by self.options,
+        This should coerce form data into the structure expected by self.user_options,
         which must be a dict.
         
-        Instances will receive this data on self.user_options, after passing through this function.
-        
-        This must be a @classmethod.
+        Instances will receive this data on self.user_options, after passing through this function,
+        prior to `Spawner.start`.
         """
         return form_data
     

jupyterhub/tests/mocking.py

@@ -76,8 +76,7 @@ class NeverSpawner(MockSpawner):
 class FormSpawner(MockSpawner):
     options_form = "IMAFORM"
     
-    @classmethod
-    def options_from_form(cls, form_data):
+    def options_from_form(self, form_data):
         options = {}
         options['notspecified'] = 5
         if 'bounds' in form_data:

jupyterhub/tests/test_pages.py

@@ -65,14 +65,14 @@ def test_spawn_redirect(app):
     assert r.url.endswith('/wash')
 
 def test_spawn_page(app):
-    with mock.patch.dict(app.tornado_application.settings, {'spawner_class': FormSpawner}):
+    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
         cookies = app.login_user('jones')
         r = get_page('spawn', app, cookies=cookies)
         assert r.url.endswith('/spawn')
         assert FormSpawner.options_form in r.text
 
 def test_spawn_form(app, io_loop):
-    with mock.patch.dict(app.tornado_application.settings, {'spawner_class': FormSpawner}):
+    with mock.patch.dict(app.users.settings, {'spawner_class': FormSpawner}):
         base_url = ujoin(app.proxy.public_server.host, app.hub.server.base_url)
         cookies = app.login_user('jones')
         orm_u = orm.User.find(app.db, 'jones')