Files
edx-platform/lms/djangoapps/completion/models.py
2017-12-14 16:40:15 -06:00

187 lines
7.0 KiB
Python

"""
Completion tracking and aggregation models.
"""
from __future__ import absolute_import, division, print_function, unicode_literals
from django.contrib.auth.models import User
from django.core.exceptions import ValidationError
from django.db import models, transaction, connection
from django.utils.translation import ugettext as _
from model_utils.models import TimeStampedModel
from opaque_keys.edx.keys import CourseKey
from openedx.core.djangoapps.xmodule_django.models import CourseKeyField, UsageKeyField
from . import waffle
# pylint: disable=ungrouped-imports
try:
from django.models import BigAutoField # New in django 1.10
except ImportError:
from openedx.core.djangolib.fields import BigAutoField
# pylint: enable=ungrouped-imports
def validate_percent(value):
"""
Verify that the passed value is between 0.0 and 1.0.
"""
if not 0.0 <= value <= 1.0:
raise ValidationError(_('{value} must be between 0.0 and 1.0').format(value=value))
class BlockCompletionManager(models.Manager):
"""
Custom manager for BlockCompletion model.
Adds submit_completion and submit_batch_completion methods.
"""
def submit_completion(self, user, course_key, block_key, completion):
"""
Update the completion value for the specified record.
Parameters:
* user (django.contrib.auth.models.User): The user for whom the
completion is being submitted.
* course_key (opaque_keys.edx.keys.CourseKey): The course in
which the submitted block is found.
* block_key (opaque_keys.edx.keys.UsageKey): The block that has had
its completion changed.
* completion (float in range [0.0, 1.0]): The fractional completion
value of the block (0.0 = incomplete, 1.0 = complete).
Return Value:
(BlockCompletion, bool): A tuple comprising the created or updated
BlockCompletion object and a boolean value indicating whether the
object was newly created by this call.
Raises:
ValueError:
If the wrong type is passed for one of the parameters.
django.core.exceptions.ValidationError:
If a float is passed that is not between 0.0 and 1.0.
django.db.DatabaseError:
If there was a problem getting, creating, or updating the
BlockCompletion record in the database.
This will also be a more specific error, as described here:
https://docs.djangoproject.com/en/1.11/ref/exceptions/#database-exceptions.
IntegrityError and OperationalError are relatively common
subclasses.
"""
# Raise ValueError to match normal django semantics for wrong type of field.
if not isinstance(course_key, CourseKey):
raise ValueError(
"course_key must be an instance of `opaque_keys.edx.keys.CourseKey`. Got {}".format(type(course_key))
)
try:
block_type = block_key.block_type
except AttributeError:
raise ValueError(
"block_key must be an instance of `opaque_keys.edx.keys.UsageKey`. Got {}".format(type(block_key))
)
if waffle.waffle().is_enabled(waffle.ENABLE_COMPLETION_TRACKING):
obj, is_new = self.get_or_create(
user=user,
course_key=course_key,
block_type=block_type,
block_key=block_key,
defaults={'completion': completion},
)
if not is_new and obj.completion != completion:
obj.completion = completion
obj.full_clean()
obj.save()
else:
# If the feature is not enabled, this method should not be called. Error out with a RuntimeError.
raise RuntimeError(
"BlockCompletion.objects.submit_completion should not be called when the feature is disabled."
)
return obj, is_new
@transaction.atomic()
def submit_batch_completion(self, user, course_key, blocks):
"""
Performs a batch insertion of completion objects.
Parameters:
* user (django.contrib.auth.models.User): The user for whom the
completions are being submitted.
* course_key (opaque_keys.edx.keys.CourseKey): The course in
which the submitted blocks are found.
* blocks: A list of tuples of UsageKey to float completion values.
(float in range [0.0, 1.0]): The fractional completion
value of the block (0.0 = incomplete, 1.0 = complete).
Return Value:
Dict of (BlockCompletion, bool): A dictionary with a
BlockCompletion object key and a value of bool. The boolean value
indicates whether the object was newly created by this call.
Raises:
ValueError:
If the wrong type is passed for one of the parameters.
django.core.exceptions.ValidationError:
If a float is passed that is not between 0.0 and 1.0.
django.db.DatabaseError:
If there was a problem getting, creating, or updating the
BlockCompletion record in the database.
"""
block_completions = {}
for block, completion in blocks:
(block_completion, is_new) = self.submit_completion(user, course_key, block, completion)
block_completions[block_completion] = is_new
return block_completions
class BlockCompletion(TimeStampedModel, models.Model):
"""
Track completion of completable blocks.
A completion is unique for each (user, course_key, block_key).
The block_type field is included separately from the block_key to
facilitate distinct aggregations of the completion of particular types of
block.
The completion value is stored as a float in the range [0.0, 1.0], and all
calculations are performed on this float, though current practice is to
only track binary completion, where 1.0 indicates that the block is
complete, and 0.0 indicates that the block is incomplete.
"""
id = BigAutoField(primary_key=True) # pylint: disable=invalid-name
user = models.ForeignKey(User)
course_key = CourseKeyField(max_length=255)
block_key = UsageKeyField(max_length=255)
block_type = models.CharField(max_length=64)
completion = models.FloatField(validators=[validate_percent])
objects = BlockCompletionManager()
class Meta(object):
index_together = [
('course_key', 'block_type', 'user'),
('user', 'course_key', 'modified'),
]
unique_together = [
('course_key', 'block_key', 'user')
]
def __unicode__(self):
return 'BlockCompletion: {username}, {course_key}, {block_key}: {completion}'.format(
username=self.user.username,
course_key=self.course_key,
block_key=self.block_key,
completion=self.completion,
)