Embed annotation object in a Canvas page

README.md

@@ -99,3 +99,4 @@ In edX, the opaque `user_id` is unique within the scope of a course. In Canvas,
 **The meaning of the ORG variable:**
 
 Older versions of the tool used a global `ORG` variable to encode some differences, but this has been deprecated and should not be used.
+

hx_lti_assignment/models.py

@@ -45,7 +45,7 @@ def get_target_external_options_list(self):
         """
         Returns a list of options that are saved to the target_external_options model attribute
         in CSV format.
-        
+
         Notes:
         - since the model attribute could be null in the database, we have to
           check if it's None before trying parse it.
@@ -323,3 +323,6 @@ def getColorValues(color):
                 except:
                     concat_tag_name += res[0] + " "
             return result
+
+    def get_target_objects(self):
+        return self.assignment_objects.all()

hx_lti_initializer/forms.py

@@ -1,6 +1,8 @@
 from django import forms
 from django.db.models import Q
-from hx_lti_assignment.models import Assignment
+from oauthlib.common import Request as OAuthRequest
+from oauthlib.oauth1 import Client as OAuthClient
+
 from hx_lti_initializer.models import LTICourse, LTIProfile
 
 
@@ -21,3 +23,85 @@ def get_course_admins(self):
     class Meta:
         model = LTICourse
         fields = ("course_name", "course_admins", "course_external_css_default")
+
+
+class EmbedLtiSelectionForm(forms.Form):
+    '''
+    This form is intended to be used as part of the LTI content item embed workflow
+    to present a selection interface to the user.
+
+    Note: Attempted to use django-crispy-forms for layout, but the crispy template
+        for RadioSelect does not render subgroups of choices.
+    '''
+
+    def __init__(self, *args, **kwargs):
+        course_instance = kwargs.pop('course_instance')
+        content_item_return_url = kwargs.pop('content_item_return_url')
+        super().__init__(*args, **kwargs)
+
+        self.fields['content_item_return_url'] = forms.CharField(
+            widget=forms.HiddenInput(),
+            initial=content_item_return_url,
+        )
+
+        choices = self._get_choices(course_instance)
+        self.fields['content_item'] = forms.ChoiceField(
+            widget=forms.RadioSelect(attrs={'class':'content_item'}),
+            choices=choices,
+            initial=self._get_initial_choice(choices),
+            required=True,
+        )
+
+    def _get_choices(self, course_instance):
+        choices = []
+        for assignment in course_instance.get_published_assignments():
+            group_name = assignment.assignment_name
+            group_choices = []
+            for target in assignment.assignment_objects.all():
+                value = f"{assignment.assignment_id}/{target.pk}"
+                label = target.target_title
+                group_choices.append((value, label))
+            choices.append((group_name, group_choices))
+        return choices
+
+    def _get_initial_choice(self, choices):
+        if len(choices) == 0:
+            return None
+        group_name, group_choices = choices[0]
+        return group_choices[0][0]
+
+
+class EmbedLtiResponseForm(forms.Form):
+    '''
+    This form is intended to be used as part of the LTI content item embed workflow
+    to return a response back to the tool consumer. Mostly it encapsulates the oauth
+    signing process.
+    '''
+
+    lti_message_type = forms.CharField(widget=forms.HiddenInput(), initial="ContentItemSelection")
+    lti_version = forms.CharField(widget=forms.HiddenInput(), initial="LTI-1p0")
+    content_items = forms.CharField(widget=forms.HiddenInput())
+    oauth_version = forms.CharField(widget=forms.HiddenInput())
+    oauth_nonce = forms.CharField(widget=forms.HiddenInput())
+    oauth_timestamp = forms.CharField(widget=forms.HiddenInput())
+    oauth_consumer_key = forms.CharField(widget=forms.HiddenInput())
+    oauth_callback = forms.CharField(widget=forms.HiddenInput())
+    oauth_signature_method = forms.CharField(widget=forms.HiddenInput())
+    oauth_signature = forms.CharField(widget=forms.HiddenInput())
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.data['lti_message_type'] = self.fields['lti_message_type'].initial
+        self.data['lti_version'] = self.fields['lti_version'].initial
+
+    def set_oauth_signature(self, url=None, consumer_key=None, consumer_secret=None):
+        body = dict(self.data)  # shallow copy
+        headers = {}
+        request = OAuthRequest(url, "POST", body, headers)
+
+        # generate the oauth params and update the form data
+        client = OAuthClient(consumer_key, client_secret=consumer_secret, callback_uri='about:blank')
+        request.oauth_params = client.get_oauth_params(request)
+        oauth_signature = client.get_oauth_signature(request)
+        request.oauth_params.append(('oauth_signature', oauth_signature))
+        self.data.update(request.oauth_params)

hx_lti_initializer/models.py

@@ -160,10 +160,16 @@ def add_user(self, lti_profile):
 
     def get_assignments(self):
         """
-        Returns a QuerySet of assignments for this course, ordered by name.
+        Returns a QuerySet of all assignments (published and unpublished) for this course, ordered by name.
         """
         return self.assignments.order_by(Lower("assignment_name"))
 
+    def get_published_assignments(self):
+        """
+        Returns a QuerySet of published assignments for this course.
+        """
+        return self.get_assignments().filter(is_published=True)
+
 
 class LTICourseAdmin(models.Model):
 

hx_lti_initializer/templates/hx_lti_initializer/embed_lti_response.html

@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <title>{% block title %}HarvardX Annotation Tool{% endblock %}</title>
+    </head>
+    <body>
+        <form id="content_item_return" action="{{ content_item_return_url }}" method="post" encType="application/x-www-form-urlencoded">
+            {{ embed_lti_response_form }}
+        </form>
+        <script>
+            var content_item_return_form = document.forms["content_item_return"];
+            console.log("HxAT submitting ContentItemSelection response...");
+            content_item_return_form.submit();
+        </script>
+    </body>
+</html>

hx_lti_initializer/templates/hx_lti_initializer/embed_lti_selection.html

@@ -0,0 +1,25 @@
+{% load staticfiles %}
+{% load bootstrap3 %}
+<!DOCTYPE html>
+<html lang="en">
+    <head>
+        <title>{% block title %}HarvardX Annotation Tool{% endblock %}</title>
+        {% bootstrap_css %}
+        <style type="text/css">
+            ul.content_item, ul.content_item ul { list-style-type: none; }
+        </style>
+    </head>
+    <body>
+        <main class="container" style="margin: 20px;">
+            {% if selection_form.fields.content_item.choices|length > 0 %}
+                <form id="lti_selection" action="{% url 'hx_lti_initializer:embed_lti_response' %}" method="post">
+                    {% csrf_token %}
+                    {{ selection_form }}
+                    <input type="submit" class="btn btn-primary" value="Insert this annotation content">
+                </form>
+            {% else %}
+                <p>No annotation content items available to add.</p>
+            {% endif %}
+        </main>
+    </body>
+</html>

hx_lti_initializer/urls.py

@@ -15,11 +15,15 @@
     instructor_dashboard_student_list_view,
     instructor_dashboard_view,
     launch_lti,
+    embed_lti,
+    embed_lti_response,
 )
 
 urlpatterns = [
     path("course/<int:id>/edit/", edit_course, name="edit_course",),
     path("launch_lti/", launch_lti, name="launch_lti",),
+    path("embed_lti/", embed_lti, name="embed_lti",),
+    path("embed_lti_response/", embed_lti_response, name="embed_lti_response",),
     path("admin_hub/", course_admin_hub, name="course_admin_hub",),
     path(
         "admin_hub/<path:course_id>/<slug:assignment_id>/<int:object_id>/preview/",