Ready to implement path_to_location

* Clean up test data for simple, toy courses
* clean up test_mongo.py
* write initial test for path_to_location
* hook up view to use path_to_location

Next: actually implement it :)

common/lib/xmodule/xmodule/modulestore/__init__.py

@@ -253,3 +253,26 @@ class ModuleStore(object):
         in this modulestore.
         '''
         raise NotImplementedError
+
+    def path_to_location(self, location, course=None, chapter=None, section=None):
+        '''
+        Try to find a course/chapter/section[/position] path to this location.
+
+        raise ItemNotFoundError if the location doesn't exist.
+
+        If course, chapter, section are not None, restrict search to paths with those
+            components as specified.
+            
+        raise NoPathToItem if the location exists, but isn't accessible via
+        a path that matches the course/chapter/section restrictions.
+
+        In general, a location may be accessible via many paths. This method may
+        return any valid path.
+
+        Return a tuple (course, chapter, section, position).
+
+        If the section a sequence, position should be the position of this location
+        in that sequence.  Otherwise, position should be None.
+        '''
+        raise NotImplementedError
+

common/lib/xmodule/xmodule/modulestore/exceptions.py

@@ -13,3 +13,6 @@ class InsufficientSpecificationError(Exception):
 
 class InvalidLocationError(Exception):
     pass
+
+class NoPathToItem(Exception):
+    pass

common/lib/xmodule/xmodule/modulestore/mongo.py

@@ -251,7 +251,7 @@ class MongoModuleStore(ModuleStore):
 
     def update_metadata(self, location, metadata):
         """
-        Set the children for the item specified by the location to
+        Set the metadata for the item specified by the location to
         metadata
 
         location: Something that can be passed to Location
@@ -264,3 +264,25 @@ class MongoModuleStore(ModuleStore):
             {'_id': Location(location).dict()},
             {'$set': {'metadata': metadata}}
         )
+
+    def path_to_location(self, location, course=None):
+        '''
+        Try to find a course/chapter/section[/position] path to this location.
+
+        raise ItemNotFoundError if the location doesn't exist.
+
+        If course is not None, restrict search to paths in that course.
+            
+        raise NoPathToItem if the location exists, but isn't accessible via
+        a chapter/section path in the course(s) being searched.
+
+        In general, a location may be accessible via many paths. This method may
+        return any valid path.
+
+        Return a tuple (course, chapter, section, position).
+
+        If the section a sequence, position should be the position of this location
+        in that sequence.  Otherwise, position should be None.
+        '''
+        raise NotImplementedError
+

common/lib/xmodule/xmodule/modulestore/tests/test_mongo.py

@@ -4,7 +4,7 @@ from nose.tools import assert_equals, assert_raises, assert_not_equals, with_set
 from path import path
 
 from xmodule.modulestore import Location
-from xmodule.modulestore.exceptions import InvalidLocationError
+from xmodule.modulestore.exceptions import InvalidLocationError, ItemNotFoundError
 from xmodule.modulestore.mongo import MongoModuleStore
 from xmodule.modulestore.xml_importer import import_from_xml
 
@@ -26,36 +26,60 @@ FS_ROOT = DATA_DIR  # TODO (vshnayder): will need a real fs_root for testing loa
 DEFAULT_CLASS = 'xmodule.raw_module.RawDescriptor'
 
 
-connection = None
+class TestMongoModuleStore(object):
 
-def setup():
-    global connection
-    connection = pymongo.connection.Connection(HOST, PORT)
-    
+    @classmethod
+    def setupClass(cls):
+        cls.connection = pymongo.connection.Connection(HOST, PORT)
+        cls.connection.drop_database(DB)
 
+    @classmethod
+    def teardownClass(cls):
+        pass
 
-def setup_func():
-    # connect to the db
-    global store
-    store = MongoModuleStore(HOST, DB, COLLECTION, FS_ROOT, default_class=DEFAULT_CLASS)
-    print 'data_dir: {0}'.format(DATA_DIR)
-    import_from_xml(store, DATA_DIR)
-    
-def teardown_func():
-    global store
-    store = None
-    # Destroy the test db.
-    connection.drop_database(DB)
+    def setUp(self):
+        # connect to the db
+        self.store = MongoModuleStore(HOST, DB, COLLECTION, FS_ROOT, default_class=DEFAULT_CLASS)
+        # Explicitly list the courses to load (don't want the big one)
+        courses = ['toy', 'simple']
+        import_from_xml(self.store, DATA_DIR, courses)
+        self.connection = TestMongoModuleStore.connection
     
+    def tearDown(self):
+        # Destroy the test db.
+        self.connection.drop_database(DB)
+        self.store = None    
 
-@with_setup(setup_func, teardown_func)
-def test_init():
-    '''Just make sure the db loads'''
-    pass
-        
-@with_setup(setup_func, teardown_func)
-def test_get_courses():
-    '''Make sure the course objects loaded properly'''
-    courses = store.get_courses()
-    print courses
+    def test_init(self):
+        '''Just make sure the db loads'''
+        ids = list(self.connection[DB][COLLECTION].find({}, {'_id': True}))
+        print len(ids)
         
+    def test_get_courses(self):
+        '''Make sure the course objects loaded properly'''
+        courses = self.store.get_courses()
+        assert_equals(len(courses), 2)
+        courses.sort(key=lambda c: c.id)
+        assert_equals(courses[0].id, 'edX/simple/2012_Fall')
+        assert_equals(courses[1].id, 'edX/toy/2012_Fall')
+
+    def Xtest_path_to_location(self):
+        '''Make sure that path_to_location works'''
+        should_work = (
+            ("i4x://edX/toy/video/Welcome", ("toy", "Overview", None, None)),
+            )
+        for location, expected in should_work:
+            assert_equals(self.store.path_to_location(location), expected)
+
+        not_found = (
+            "i4x://edX/toy/video/WelcomeX",
+            )
+        for location in not_found:
+            assert_raises(ItemNotFoundError, self.store.path_to_location, location)
+            
+        no_path = (
+            "i4x://edX/toy/video/Lost_Video",
+            )
+        for location in not_found:
+            assert_raises(ItemNotFoundError, self.store.path_to_location, location)
+            

common/test/data/simple/course.xml

+<course name="A Simple Course" org="edX" course="simple" graceperiod="1 day 5 hours 59 minutes 59 seconds" slug="2012_Fall">
+  <chapter name="Overview">
+    <video name="Welcome" youtube="0.75:izygArpw-Qo,1.0:p2Q6BrNhdh8,1.25:1EeWXzPdhSA,1.50:rABDYkeK0x8"/>
+    <videosequence format="Lecture Sequence" name="A simple sequence">
+      <html id="toylab" filename="toylab"/>
+      <video name="S0V1: Video Resources" youtube="0.75:EuzkdzfR0i8,1.0:1bK-WdDi6Qw,1.25:0v1VzoDVUTM,1.50:Bxk_-ZJb240"/>
+    </videosequence>
+    <section name="Lecture 2">
+    <sequential>
+        <video youtube="1.0:TBvX7HzxexQ"/>
+        <problem name="L1 Problem 1" points="1" type="lecture" showanswer="attempted" filename="L1_Problem_1" rerandomize="never"/>
+      </sequential>
+    </section>
+  </chapter>
+  <chapter name="Chapter 2">
+    <section name="Problem Set 1">
+      <sequential>
+        <problem type="lecture" showanswer="attempted" rerandomize="true" title="A simple coding problem" name="Simple coding problem" filename="ps01-simple"/>
+      </sequential>
+    </section>
+  </chapter>
+  <video name="Lost Video" youtube="1.0:TBvX7HzxexQ"/>
+
+</course>

common/test/data/simple/html/toylab.html

+<b>Lab 2A: Superposition Experiment</b>
+
+<p>Isn't the toy course great?</p>

common/test/data/simple/problems/L1_Problem_1.xml

+<?xml version="1.0"?>
+<problem>
+  <p>
+    <h1>Finger Exercise 1</h1>
+  </p>
+  <p>
+Here are two definitions: </p>
+  <ol class="enumerate">
+    <li>
+      <p>
+Declarative knowledge refers to statements of fact. </p>
+    </li>
+    <li>
+      <p>
+Imperative knowledge refers to 'how to' methods. </p>
+    </li>
+  </ol>
+  <p>
+Which of the following choices is correct? </p>
+  <ol class="enumerate">
+    <li>
+      <p>
+Statement 1 is true, Statement 2 is false </p>
+    </li>
+    <li>
+      <p>
+Statement 1 is false, Statement 2 is true </p>
+    </li>
+    <li>
+      <p>
+Statement 1 and Statement 2 are both false </p>
+    </li>
+    <li>
+      <p>
+Statement 1 and Statement 2 are both true </p>
+    </li>
+  </ol>
+  <p>
+    <symbolicresponse answer="4">
+      <textline size="90" math="1"/>
+    </symbolicresponse>
+  </p>
+</problem>

common/test/data/simple/problems/ps01-simple.xml

+<problem><style media="all" type="text/css"/>
+<text><h2>Paying Off Credit Card Debt</h2>
+<p> Each month, a credit
+      card statement will come with the option for you to pay a
+      minimum amount of your charge, usually 2% of the balance due.
+      However, the credit card company earns money by charging
+      interest on the balance that you don't pay. So even if you
+      pay credit card payments on time, interest is still accruing
+      on the outstanding balance.</p>
+<p >Say you've made a
+      $5,000 purchase on a credit card with 18% annual interest
+      rate and 2% minimum monthly payment rate. After a year, how
+      much is the remaining balance? Use the following
+      equations.</p>
+<blockquote>
+<p><strong>Minimum monthly payment</strong>
+= (Minimum monthly payment rate) x (Balance)<br/>
+        (Minimum monthly payment gets split into interest paid and
+        principal paid)<br/>
+<strong>Interest Paid</strong> = (Annual interest rate) / (12
+        months) x (Balance)<br/>
+<strong>Principal paid</strong> = (Minimum monthly payment) -
+        (Interest paid)<br/>
+<strong>Remaining balance</strong> = Balance - (Principal
+        paid)</p>
+</blockquote>
+<p >For month 1, compute the minimum monthly payment by taking 2% of the balance.</p>
+<blockquote xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:x="urn:schemas-microsoft-com:office:excel">
+<p><strong>Minimum monthly payment</strong>
+= .02 x $5000 = $100</p>
+<p>We can't simply deduct this from the balance because
+        there is compounding interest. Of this $100 monthly
+        payment, compute how much will go to paying off interest
+        and how much will go to paying off the principal. Remember
+        that it's the annual interest rate that is given, so we
+        need to divide it by 12 to get the monthly interest
+        rate.</p>
+<p><strong>Interest paid</strong> = .18/12 x $5000 =
+        $75<br/>
+<strong>Principal paid</strong> = $100 - $75 = $25</p>
+<p>The remaining balance at the end of the first month will
+        be the principal paid this month subtracted from the
+        balance at the start of the month.</p>
+<p><strong>Remaining balance</strong> = $5000 - $25 =
+        $4975</p>
+</blockquote>
+<p xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:x="urn:schemas-microsoft-com:office:excel">For month 2, we
+      repeat the same steps.</p>
+<blockquote xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:x="urn:schemas-microsoft-com:office:excel">
+<p><strong>Minimum monthly payment</strong>
+= .02 x $4975 = $99.50<br/>
+<strong>Interest Paid</strong> = .18/12 x $4975 =
+        $74.63<br/>
+<strong>Principal Paid</strong> = $99.50 - $74.63 =
+        $24.87<br/>
+<strong>Remaining Balance</strong> = $4975 - $24.87 =
+        $4950.13</p>
+</blockquote>
+<p xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:v="urn:schemas-microsoft-com:vml" xmlns:x="urn:schemas-microsoft-com:office:excel">After 12 months, the
+      total amount paid is $1167.55, leaving an outstanding balance
+      of $4708.10. Pretty depressing!</p>
+</text></problem>

common/test/data/toy/course.xml

 <course name="Toy Course" org="edX" course="toy" graceperiod="1 day 5 hours 59 minutes 59 seconds" slug="2012_Fall" start="2015-07-17T12:00">
   <chapter name="Overview">
-    <video name="Welcome" youtube="0.75:izygArpw-Qo,1.0:p2Q6BrNhdh8,1.25:1EeWXzPdhSA,1.50:rABDYkeK0x8"/>
+    <video name="Welcome" youtube="1.0:p2Q6BrNhdh8"/>
     <videosequence format="Lecture Sequence" name="System Usage Sequence">
       <html id="toylab" filename="toylab"/>
-      <video name="S0V1: Video Resources" youtube="0.75:EuzkdzfR0i8,1.0:1bK-WdDi6Qw,1.25:0v1VzoDVUTM,1.50:Bxk_-ZJb240"/>
+      <video name="S0V1: Video Resources" youtube="1.0:1bK-WdDi6Qw"/>
     </videosequence>
   </chapter>
 </course>

lms/djangoapps/courseware/views.py

@@ -21,7 +21,7 @@ from models import StudentModuleCache
 from student.models import UserProfile
 from multicourse import multicourse_settings
 from xmodule.modulestore import Location
-from xmodule.modulestore.exceptions import InvalidLocationError, ItemNotFoundError
+from xmodule.modulestore.exceptions import InvalidLocationError, ItemNotFoundError, NoPathToItem
 from xmodule.modulestore.django import modulestore
 from xmodule.course_module import CourseDescriptor
 
@@ -228,11 +228,14 @@ def jump_to(request, location):
 
     # Complain if there's not data for this location
     try:
-        item = modulestore().get_item(location)
+        (course, chapter, section, position) = modulestore().path_to_location(location)
     except ItemNotFoundError:
         raise Http404("No data at this location: {0}".format(location))
-        
-    return HttpResponse("O hai")
+    except NoPathToItem:
+        raise Http404("This location is not in any class: {0}".format(location))
+    
+
+    return index(course, chapter, section, position)
 
 @ensure_csrf_cookie
 def course_info(request, course_id):