From 49217ebe8bd8eba20fb167831c8157a52b4d8b97 Mon Sep 17 00:00:00 2001
From: Calen Pennington <cale@edx.org>
Date: Fri, 13 Dec 2013 07:47:21 -0500
Subject: [PATCH] Allow multiple client-side runtimes on a single page

Make XBlock client-side runtimes proper classes, so that handlerUrl can
be defined in a per-runtime way, and we can have multiple runtimes on a
single page.

[LMS-1630][LMS-1421][LMS-1517]
---
 cms/djangoapps/contentstore/views/item.py     |  9 +-
 cms/djangoapps/contentstore/views/preview.py  | 22 ++---
 cms/lib/xblock/runtime.py                     |  2 -
 cms/static/coffee/spec/main.coffee            |  1 +
 cms/static/coffee/spec/main_squire.coffee     |  1 +
 .../coffee/src/views/module_edit.coffee       |  2 +-
 .../coffee/src/xblock/cms.runtime.v1.coffee   | 22 +++++
 cms/static/js_test.yml                        |  3 +-
 cms/static/js_test_squire.yml                 |  2 +
 common/djangoapps/xmodule_modifiers.py        | 14 +--
 common/static/coffee/src/xblock/core.coffee   |  9 +-
 .../coffee/src/xblock/runtime.v1.coffee       | 29 ++-----
 lms/djangoapps/courseware/module_render.py    |  7 +-
 .../instructor/views/instructor_dashboard.py  |  3 +-
 lms/djangoapps/instructor/views/legacy.py     |  3 +-
 lms/envs/common.py                            | 12 +--
 lms/lib/xblock/runtime.py                     | 86 ++++++-------------
 .../coffee/src/xblock/lms.runtime.v1.coffee   | 18 ++++
 lms/static/js_test.yml                        |  1 +
 19 files changed, 122 insertions(+), 124 deletions(-)
 create mode 100644 cms/static/coffee/src/xblock/cms.runtime.v1.coffee
 create mode 100644 lms/static/coffee/src/xblock/lms.runtime.v1.coffee

diff --git a/cms/djangoapps/contentstore/views/item.py b/cms/djangoapps/contentstore/views/item.py
index 3d8f81a6ef..725f394d14 100644
--- a/cms/djangoapps/contentstore/views/item.py
+++ b/cms/djangoapps/contentstore/views/item.py
@@ -10,6 +10,7 @@ from xmodule_modifiers import wrap_xblock
 from django.core.exceptions import PermissionDenied
 from django.contrib.auth.decorators import login_required
 from django.http import HttpResponseBadRequest
+from django.utils.translation import ugettext as _
 from django.views.decorators.http import require_http_methods
 
 from xblock.fields import Scope
@@ -34,7 +35,7 @@ from .helpers import _xmodule_recurse
 from preview import handler_prefix, get_preview_html
 from edxmako.shortcuts import render_to_response, render_to_string
 from models.settings.course_grading import CourseGradingModel
-from django.utils.translation import ugettext as _
+from cms.lib.xblock.runtime import handler_url
 
 __all__ = ['orphan_handler', 'xblock_handler']
 
@@ -43,6 +44,12 @@ log = logging.getLogger(__name__)
 CREATE_IF_NOT_FOUND = ['course_info']
 
 
+# In order to allow descriptors to use a handler url, we need to
+# monkey-patch the x_module library.
+# TODO: Remove this code when Runtimes are no longer created by modulestores
+xmodule.x_module.descriptor_global_handler_url = handler_url
+
+
 # pylint: disable=unused-argument
 @require_http_methods(("DELETE", "GET", "PUT", "POST"))
 @login_required
diff --git a/cms/djangoapps/contentstore/views/preview.py b/cms/djangoapps/contentstore/views/preview.py
index 11bea40f9f..732323e924 100644
--- a/cms/djangoapps/contentstore/views/preview.py
+++ b/cms/djangoapps/contentstore/views/preview.py
@@ -33,20 +33,6 @@ __all__ = ['preview_handler']
 log = logging.getLogger(__name__)
 
 
-def handler_prefix(block, handler='', suffix=''):
-    """
-    Return a url prefix for XBlock handler_url. The full handler_url
-    should be '{prefix}/{handler}/{suffix}?{query}'.
-
-    Trailing `/`s are removed from the returned url.
-    """
-    return reverse('preview_handler', kwargs={
-        'usage_id': quote_slashes(unicode(block.scope_ids.usage_id).encode('utf-8')),
-        'handler': handler,
-        'suffix': suffix,
-    }).rstrip('/?')
-
-
 @login_required
 def preview_handler(request, usage_id, handler, suffix=''):
     """
@@ -91,7 +77,11 @@ class PreviewModuleSystem(ModuleSystem):  # pylint: disable=abstract-method
     An XModule ModuleSystem for use in Studio previews
     """
     def handler_url(self, block, handler_name, suffix='', query='', thirdparty=False):
-        return handler_prefix(block, handler_name, suffix) + '?' + query
+        return reverse('preview_handler', kwargs={
+            'usage_id': quote_slashes(unicode(block.scope_ids.usage_id).encode('utf-8')),
+            'handler': handler_name,
+            'suffix': suffix,
+        }) + '?' + query
 
 
 def _preview_module_system(request, descriptor):
@@ -123,7 +113,7 @@ def _preview_module_system(request, descriptor):
         # Set up functions to modify the fragment produced by student_view
         wrappers=(
             # This wrapper wraps the module in the template specified above
-            partial(wrap_xblock, handler_prefix, display_name_only=descriptor.location.category == 'static_tab'),
+            partial(wrap_xblock, 'PreviewRuntime', display_name_only=descriptor.location.category == 'static_tab'),
 
             # This wrapper replaces urls in the output that start with /static
             # with the correct course-specific url for the static content
diff --git a/cms/lib/xblock/runtime.py b/cms/lib/xblock/runtime.py
index 5c749a34c6..36437c4750 100644
--- a/cms/lib/xblock/runtime.py
+++ b/cms/lib/xblock/runtime.py
@@ -4,7 +4,6 @@ XBlock runtime implementations for edX Studio
 
 from django.core.urlresolvers import reverse
 
-import xmodule.x_module
 from lms.lib.xblock.runtime import quote_slashes
 
 
@@ -27,4 +26,3 @@ def handler_url(block, handler_name, suffix='', query='', thirdparty=False):
 
     return url
 
-xmodule.x_module.descriptor_global_handler_url = handler_url
diff --git a/cms/static/coffee/spec/main.coffee b/cms/static/coffee/spec/main.coffee
index 2cbc85d7c1..705ff08238 100644
--- a/cms/static/coffee/spec/main.coffee
+++ b/cms/static/coffee/spec/main.coffee
@@ -28,6 +28,7 @@ requirejs.config({
         "tinymce": "xmodule_js/common_static/js/vendor/tiny_mce/tiny_mce",
         "jquery.tinymce": "xmodule_js/common_static/js/vendor/tiny_mce/jquery.tinymce",
         "xmodule": "xmodule_js/src/xmodule",
+        "xblock/cms.runtime.v1": "coffee/src/xblock/cms.runtime.v1",
         "xblock": "xmodule_js/common_static/coffee/src/xblock",
         "utility": "xmodule_js/common_static/js/src/utility",
         "accessibility": "xmodule_js/common_static/js/src/accessibility_tools",
diff --git a/cms/static/coffee/spec/main_squire.coffee b/cms/static/coffee/spec/main_squire.coffee
index a8e052fd2e..bc19272283 100644
--- a/cms/static/coffee/spec/main_squire.coffee
+++ b/cms/static/coffee/spec/main_squire.coffee
@@ -27,6 +27,7 @@ requirejs.config({
         "tinymce": "xmodule_js/common_static/js/vendor/tiny_mce/tiny_mce",
         "jquery.tinymce": "xmodule_js/common_static/js/vendor/tiny_mce/jquery.tinymce",
         "xmodule": "xmodule_js/src/xmodule",
+        "xblock/cms.runtime.v1": "coffee/src/xblock/cms.runtime.v1",
         "xblock": "xmodule_js/common_static/coffee/src/xblock",
         "utility": "xmodule_js/common_static/js/src/utility",
         "sinon": "xmodule_js/common_static/js/vendor/sinon-1.7.1",
diff --git a/cms/static/coffee/src/views/module_edit.coffee b/cms/static/coffee/src/views/module_edit.coffee
index a9628b628f..a30fbe9db1 100644
--- a/cms/static/coffee/src/views/module_edit.coffee
+++ b/cms/static/coffee/src/views/module_edit.coffee
@@ -1,6 +1,6 @@
 define ["backbone", "jquery", "underscore", "gettext", "xblock/runtime.v1",
         "js/views/feedback_notification", "js/views/metadata", "js/collections/metadata"
-        "js/utils/modal", "jquery.inputnumber", "xmodule", "coffee/src/main"],
+        "js/utils/modal", "jquery.inputnumber", "xmodule", "coffee/src/main", "xblock/cms.runtime.v1"],
 (Backbone, $, _, gettext, XBlock, NotificationView, MetadataView, MetadataCollection, ModalUtils) ->
   class ModuleEdit extends Backbone.View
     tagName: 'li'
diff --git a/cms/static/coffee/src/xblock/cms.runtime.v1.coffee b/cms/static/coffee/src/xblock/cms.runtime.v1.coffee
new file mode 100644
index 0000000000..4eddd6ef3a
--- /dev/null
+++ b/cms/static/coffee/src/xblock/cms.runtime.v1.coffee
@@ -0,0 +1,22 @@
+define ["jquery", "xblock/runtime.v1", "URI"], ($, XBlock, URI) ->
+    @PreviewRuntime = {}
+
+    class PreviewRuntime.v1 extends XBlock.Runtime.v1
+      handlerUrl: (element, handlerName, suffix, query, thirdparty) ->
+        uri = URI("/preview/xblock").segment($(@element).data('usage-id'))
+                                    .segment('handler')
+                                    .segment(handlerName)
+        if suffix? then uri.segment(suffix)
+        if query? then uri.search(query)
+        uri.toString()
+
+    @StudioRuntime = {}
+
+    class StudioRuntime.v1 extends XBlock.Runtime.v1
+      handlerUrl: (element, handlerName, suffix, query, thirdparty) ->
+        uri = URI("/xblock").segment($(@element).data('usage-id'))
+                                    .segment('handler')
+                                    .segment(handlerName)
+        if suffix? then uri.segment(suffix)
+        if query? then uri.search(query)
+        uri.toString()
diff --git a/cms/static/js_test.yml b/cms/static/js_test.yml
index 17d4805be0..ce247967a9 100644
--- a/cms/static/js_test.yml
+++ b/cms/static/js_test.yml
@@ -59,7 +59,8 @@ lib_paths:
     - xmodule_js/common_static/js/vendor/URI.min.js
     - xmodule_js/common_static/js/vendor/jquery.smooth-scroll.min.js
     - xmodule_js/common_static/coffee/src/jquery.immediateDescendents.js
-    - xmodule_js/common_static/coffee/src/xblock
+    - xmodule_js/common_static/coffee/src/xblock/
+    - xmodule_js/common_static/js/vendor/URI.min.js
 
 # Paths to source JavaScript files
 src_paths:
diff --git a/cms/static/js_test_squire.yml b/cms/static/js_test_squire.yml
index 8f57291b3d..c8a5ff439d 100644
--- a/cms/static/js_test_squire.yml
+++ b/cms/static/js_test_squire.yml
@@ -54,6 +54,8 @@ lib_paths:
     - xmodule_js/src/xmodule.js
     - xmodule_js/common_static/coffee/src/jquery.immediateDescendents.js
     - xmodule_js/common_static/js/test/i18n.js
+    - xmodule_js/common_static/coffee/src/xblock/
+    - xmodule_js/common_static/js/vendor/URI.min.js
 
 # Paths to source JavaScript files
 src_paths:
diff --git a/common/djangoapps/xmodule_modifiers.py b/common/djangoapps/xmodule_modifiers.py
index f7b314d775..1b095bf917 100644
--- a/common/djangoapps/xmodule_modifiers.py
+++ b/common/djangoapps/xmodule_modifiers.py
@@ -15,6 +15,7 @@ from xblock.fragment import Fragment
 from xmodule.seq_module import SequenceModule
 from xmodule.vertical_module import VerticalModule
 from xmodule.x_module import shim_xmodule_js, XModuleDescriptor, XModule
+from lms.lib.xblock.runtime import quote_slashes
 
 log = logging.getLogger(__name__)
 
@@ -29,26 +30,28 @@ def wrap_fragment(fragment, new_content):
     return wrapper_frag
 
 
-def wrap_xblock(handler_prefix, block, view, frag, context, display_name_only=False):  # pylint: disable=unused-argument
+def wrap_xblock(runtime_class, block, view, frag, context, display_name_only=False, extra_data=None):  # pylint: disable=unused-argument
     """
     Wraps the results of rendering an XBlock view in a standard <section> with identifying
     data so that the appropriate javascript module can be loaded onto it.
 
-    :param handler_prefix: A function that takes a block and returns the url prefix for
-        the javascript handler_url. This prefix should be able to have {handler_name}/{suffix}?{query}
-        appended to it to return a valid handler_url
+    :param runtime_class: The name of the javascript runtime class to use to load this block
     :param block: An XBlock (that may be an XModule or XModuleDescriptor)
     :param view: The name of the view that rendered the fragment being wrapped
     :param frag: The :class:`Fragment` to be wrapped
     :param context: The context passed to the view being rendered
     :param display_name_only: If true, don't render the fragment content at all.
         Instead, just render the `display_name` of `block`
+    :param extra_data: A dictionary with extra data values to be set on the wrapper
     """
+    if extra_data is None:
+        extra_data = {}
 
     # If any mixins have been applied, then use the unmixed class
     class_name = getattr(block, 'unmixed_class', block.__class__).__name__
 
     data = {}
+    data.update(extra_data)
     css_classes = ['xblock', 'xblock-' + view]
 
     if isinstance(block, (XModule, XModuleDescriptor)):
@@ -65,9 +68,10 @@ def wrap_xblock(handler_prefix, block, view, frag, context, display_name_only=Fa
 
     if frag.js_init_fn:
         data['init'] = frag.js_init_fn
+        data['runtime-class'] = runtime_class
         data['runtime-version'] = frag.js_init_version
-        data['handler-prefix'] = handler_prefix(block)
         data['block-type'] = block.scope_ids.block_type
+        data['usage-id'] = quote_slashes(str(block.scope_ids.usage_id))
 
     template_context = {
         'content': block.display_name if display_name_only else frag.content,
diff --git a/common/static/coffee/src/xblock/core.coffee b/common/static/coffee/src/xblock/core.coffee
index 71fbfd291e..9c5cc0961c 100644
--- a/common/static/coffee/src/xblock/core.coffee
+++ b/common/static/coffee/src/xblock/core.coffee
@@ -1,18 +1,19 @@
 @XBlock =
-  runtime: {}
+  Runtime: {}
 
   initializeBlock: (element) ->
     $element = $(element)
     children = @initializeBlocks($element)
+    runtime = $element.data("runtime-class")
     version = $element.data("runtime-version")
     initFnName = $element.data("init")
-    if version? and initFnName?
-      runtime = @runtime["v#{version}"](element, children)
+    if runtime? and version? and initFnName?
+      runtime = new window[runtime]["v#{version}"](element, children)
       initFn = window[initFnName]
       block = initFn(runtime, element) ? {}
     else
       elementTag = $('<div>').append($element.clone()).html();
-      console.log("Block #{elementTag} is missing data-runtime-version or data-init, and can't be initialized")
+      console.log("Block #{elementTag} is missing data-runtime, data-runtime-version or data-init, and can't be initialized")
       block = {}
 
     block.element = element
diff --git a/common/static/coffee/src/xblock/runtime.v1.coffee b/common/static/coffee/src/xblock/runtime.v1.coffee
index efb9944bd2..b3f28242ab 100644
--- a/common/static/coffee/src/xblock/runtime.v1.coffee
+++ b/common/static/coffee/src/xblock/runtime.v1.coffee
@@ -1,24 +1,5 @@
-@XBlock.runtime.v1 = (element, children) ->
-  childMap = {}
-  $.each children, (idx, child) ->
-    childMap[child.name] = child
-
-  return {
-    # Generate the handler url for the specified handler.
-    #
-    # element is the html element containing the xblock requesting the url
-    # handlerName is the name of the handler
-    # suffix is the optional url suffix to include in the handler url
-    # query is an optional query-string (note, this should not include a preceding ? or &)
-    handlerUrl: (element, handlerName, suffix, query) ->
-      handlerPrefix = $(element).data("handler-prefix")
-      suffix = if suffix? then "/#{suffix}" else ''
-      query = if query? then "?#{query}" else ''
-      "#{handlerPrefix}/#{handlerName}#{suffix}#{query}"
-
-    # A list of xblock children of this element
-    children: children
-
-    # A map of name -> child for the xblock children of this element
-    childMap: childMap
-  }
+class XBlock.Runtime.v1
+  constructor: (@element, @children) ->
+    @childMap = {}
+    $.each @children, (idx, child) =>
+      @childMap[child.name] = child
diff --git a/lms/djangoapps/courseware/module_render.py b/lms/djangoapps/courseware/module_render.py
index 207e46f638..952d3734df 100644
--- a/lms/djangoapps/courseware/module_render.py
+++ b/lms/djangoapps/courseware/module_render.py
@@ -21,7 +21,7 @@ from courseware.access import has_access, get_user_role
 from courseware.masquerade import setup_masquerade
 from courseware.model_data import FieldDataCache, DjangoKeyValueStore
 from lms.lib.xblock.field_data import LmsFieldData
-from lms.lib.xblock.runtime import LmsModuleSystem, handler_prefix, unquote_slashes
+from lms.lib.xblock.runtime import LmsModuleSystem, unquote_slashes
 from edxmako.shortcuts import render_to_string
 from psychometrics.psychoanalyze import make_psychometrics_data_update_handler
 from student.models import anonymous_id_for_user, user_by_anonymous_id
@@ -339,7 +339,7 @@ def get_module_for_descriptor_internal(user, descriptor, field_data_cache, cours
     # Wrap the output display in a single div to allow for the XModule
     # javascript to be bound correctly
     if wrap_xmodule_display is True:
-        block_wrappers.append(partial(wrap_xblock, partial(handler_prefix, course_id)))
+        block_wrappers.append(partial(wrap_xblock, 'LmsRuntime', extra_data={'course-id': course_id}))
 
     # TODO (cpennington): When modules are shared between courses, the static
     # prefix is going to have to be specific to the module, not the directory
@@ -379,7 +379,8 @@ def get_module_for_descriptor_internal(user, descriptor, field_data_cache, cours
     # As we have the time to manually test more modules, we can add to the list
     # of modules that get the per-course anonymized id.
     is_pure_xblock = isinstance(descriptor, XBlock) and not isinstance(descriptor, XModuleDescriptor)
-    is_lti_module = not is_pure_xblock and issubclass(descriptor.module_class, LTIModule)
+    module_class = getattr(descriptor, 'module_class', None)
+    is_lti_module = not is_pure_xblock and issubclass(module_class, LTIModule)
     if is_pure_xblock or is_lti_module:
         anonymous_student_id = anonymous_id_for_user(user, course_id)
     else:
diff --git a/lms/djangoapps/instructor/views/instructor_dashboard.py b/lms/djangoapps/instructor/views/instructor_dashboard.py
index 2000c83900..ef58761c54 100644
--- a/lms/djangoapps/instructor/views/instructor_dashboard.py
+++ b/lms/djangoapps/instructor/views/instructor_dashboard.py
@@ -24,7 +24,6 @@ from django_comment_client.utils import has_forum_access
 from django_comment_common.models import FORUM_ROLE_ADMINISTRATOR
 from student.models import CourseEnrollment
 from bulk_email.models import CourseAuthorization
-from lms.lib.xblock.runtime import handler_prefix
 
 
 from .tools import get_units_with_due_date, title_or_url
@@ -206,7 +205,7 @@ def _section_send_email(course_id, access, course):
         ScopeIds(None, None, None, 'i4x://dummy_org/dummy_course/html/dummy_name')
     )
     fragment = course.system.render(html_module, 'studio_view')
-    fragment = wrap_xblock(partial(handler_prefix, course_id), html_module, 'studio_view', fragment, None)
+    fragment = wrap_xblock('LmsRuntime', html_module, 'studio_view', fragment, None, extra_data={"course-id": course_id})
     email_editor = fragment.content
     section_data = {
         'section_key': 'send_email',
diff --git a/lms/djangoapps/instructor/views/legacy.py b/lms/djangoapps/instructor/views/legacy.py
index c671b28922..0fabf5d376 100644
--- a/lms/djangoapps/instructor/views/legacy.py
+++ b/lms/djangoapps/instructor/views/legacy.py
@@ -61,7 +61,6 @@ import track.views
 from xblock.field_data import DictFieldData
 from xblock.fields import ScopeIds
 from django.utils.translation import ugettext as _u
-from lms.lib.xblock.runtime import handler_prefix
 
 from microsite_configuration.middleware import MicrositeConfiguration
 
@@ -848,7 +847,7 @@ def instructor_dashboard(request, course_id):
             ScopeIds(None, None, None, 'i4x://dummy_org/dummy_course/html/dummy_name')
         )
         fragment = html_module.render('studio_view')
-        fragment = wrap_xblock(partial(handler_prefix, course_id), html_module, 'studio_view', fragment, None)
+        fragment = wrap_xblock('LmsRuntime', html_module, 'studio_view', fragment, None, extra_data={"course-id": course_id})
         email_editor = fragment.content
 
     # Enable instructor email only if the following conditions are met:
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 5bc8f27d32..7ffd64b4ea 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -754,6 +754,7 @@ main_vendor_js = [
     'js/vendor/ova/ova.js',
     'js/vendor/ova/catch/js/catch.js',
     'js/vendor/ova/catch/js/handlebars-1.1.2.js'
+    'js/vendor/URI.min.js'
 ]
 
 discussion_js = sorted(rooted_glob(COMMON_ROOT / 'static', 'coffee/src/discussion/**/*.js'))
@@ -819,17 +820,18 @@ PIPELINE_CSS = {
 }
 
 
+common_js = set(rooted_glob(COMMON_ROOT / 'static', 'coffee/src/**/*.js')) - set(courseware_js + discussion_js + staff_grading_js + open_ended_js + notes_js + instructor_dash_js)
+project_js = set(rooted_glob(PROJECT_ROOT / 'static', 'coffee/src/**/*.js')) - set(courseware_js + discussion_js + staff_grading_js + open_ended_js + notes_js + instructor_dash_js)
+
+
+
 # test_order: Determines the position of this chunk of javascript on
 # the jasmine test page
 PIPELINE_JS = {
     'application': {
 
         # Application will contain all paths not in courseware_only_js
-        'source_filenames': sorted(
-            set(rooted_glob(COMMON_ROOT / 'static', 'coffee/src/**/*.js') +
-                rooted_glob(PROJECT_ROOT / 'static', 'coffee/src/**/*.js')) -
-            set(courseware_js + discussion_js + staff_grading_js + open_ended_js + notes_js + instructor_dash_js)
-        ) + [
+        'source_filenames': sorted(common_js) + sorted(project_js) + [
             'js/form.ext.js',
             'js/my_courses_dropdown.js',
             'js/toggle_login_modal.js',
diff --git a/lms/lib/xblock/runtime.py b/lms/lib/xblock/runtime.py
index 74066a6af1..a339a0a98a 100644
--- a/lms/lib/xblock/runtime.py
+++ b/lms/lib/xblock/runtime.py
@@ -58,63 +58,6 @@ def unquote_slashes(text):
     return re.sub(r'(;;|;_)', _unquote_slashes, text)
 
 
-def handler_url(course_id, block, handler, suffix='', query='', thirdparty=False):
-    """
-    Return an XBlock handler url for the specified course, block and handler.
-
-    If handler is an empty string, this function is being used to create a
-    prefix of the general URL, which is assumed to be followed by handler name
-    and suffix.
-
-    If handler is specified, then it is checked for being a valid handler
-    function, and ValueError is raised if not.
-
-    """
-    view_name = 'xblock_handler'
-    if handler:
-        # Be sure this is really a handler.
-        func = getattr(block, handler, None)
-        if not func:
-            raise ValueError("{!r} is not a function name".format(handler))
-        if not getattr(func, "_is_xblock_handler", False):
-            raise ValueError("{!r} is not a handler name".format(handler))
-
-    if thirdparty:
-        view_name = 'xblock_handler_noauth'
-
-    url = reverse(view_name, kwargs={
-        'course_id': course_id,
-        'usage_id': quote_slashes(unicode(block.scope_ids.usage_id).encode('utf-8')),
-        'handler': handler,
-        'suffix': suffix,
-    })
-
-    # If suffix is an empty string, remove the trailing '/'
-    if not suffix:
-        url = url.rstrip('/')
-
-    # If there is a query string, append it
-    if query:
-        url += '?' + query
-
-    return url
-
-
-def handler_prefix(course_id, block):
-    """
-    Returns a prefix for use by the Javascript handler_url function.
-
-    The prefix is a valid handler url after the handler name is slash-appended
-    to it.
-    """
-    # This depends on handler url having the handler_name as the final piece of the url
-    # so that leaving an empty handler_name really does leave the opportunity to append
-    # the handler_name on the frontend
-
-    # This is relied on by the xblock/runtime.v1.coffee frontend handlerUrl function
-    return handler_url(course_id, block, '').rstrip('/?')
-
-
 class LmsHandlerUrls(object):
     """
     A runtime mixin that provides a handler_url function that routes
@@ -127,7 +70,34 @@ class LmsHandlerUrls(object):
     # pylint: disable=no-member
     def handler_url(self, block, handler_name, suffix='', query='', thirdparty=False):
         """See :method:`xblock.runtime:Runtime.handler_url`"""
-        return handler_url(self.course_id, block, handler_name, suffix='', query='', thirdparty=thirdparty)
+        view_name = 'xblock_handler'
+        if handler_name:
+            # Be sure this is really a handler.
+            func = getattr(block, handler_name, None)
+            if not func:
+                raise ValueError("{!r} is not a function name".format(handler_name))
+            if not getattr(func, "_is_xblock_handler", False):
+                raise ValueError("{!r} is not a handler name".format(handler_name))
+
+        if thirdparty:
+            view_name = 'xblock_handler_noauth'
+
+        url = reverse(view_name, kwargs={
+            'course_id': self.course_id,
+            'usage_id': quote_slashes(unicode(block.scope_ids.usage_id).encode('utf-8')),
+            'handler': handler_name,
+            'suffix': suffix,
+        })
+
+        # If suffix is an empty string, remove the trailing '/'
+        if not suffix:
+            url = url.rstrip('/')
+
+        # If there is a query string, append it
+        if query:
+            url += '?' + query
+
+        return url
 
 
 class LmsModuleSystem(LmsHandlerUrls, ModuleSystem):  # pylint: disable=abstract-method
diff --git a/lms/static/coffee/src/xblock/lms.runtime.v1.coffee b/lms/static/coffee/src/xblock/lms.runtime.v1.coffee
new file mode 100644
index 0000000000..9a999727a3
--- /dev/null
+++ b/lms/static/coffee/src/xblock/lms.runtime.v1.coffee
@@ -0,0 +1,18 @@
+@LmsRuntime = {}
+
+class LmsRuntime.v1 extends XBlock.Runtime.v1
+  handlerUrl: (element, handlerName, suffix, query, thirdparty) ->
+    courseId = $(@element).data("course-id")
+    usageId = $(@element).data("usage-id")
+    handlerAuth = if thirdparty then "handler_noauth" else "handler"
+
+    uri = URI('/courses').segment(courseId)
+                         .segment('xblock')
+                         .segment(usageId)
+                         .segment(handlerAuth)
+                         .segment(handlerName)
+
+    if suffix? then uri.segment(suffix)
+    if query? then uri.search(query)
+
+    uri.toString()
diff --git a/lms/static/js_test.yml b/lms/static/js_test.yml
index 6fa88250ff..4cec8c06e7 100644
--- a/lms/static/js_test.yml
+++ b/lms/static/js_test.yml
@@ -40,6 +40,7 @@ lib_paths:
     - xmodule_js/common_static/js/vendor/jquery.cookie.js
     - xmodule_js/common_static/js/vendor/flot/jquery.flot.js
     - xmodule_js/common_static/js/vendor/CodeMirror/codemirror.js
+    - xmodule_js/common_static/js/vendor/URI.min.js
     - xmodule_js/common_static/coffee/src/jquery.immediateDescendents.js
     - xmodule_js/common_static/coffee/src/xblock
     - xmodule_js/src/capa/