Files
edx-platform/lms/djangoapps/certificates/api.py
Zia Fazal 2467d6971f ziafazal/SOL-1044: Database-Driven Certificate Templates
* added certificate template model
* added certificate template asset model
* added django admin configs and migration
* initial LMS template matching logic
* improved LMS template matching
* improved LMS template matching and rendering logic
* address Django admin form/model load order incongruence
* add missing unique constraint migration.
2015-08-13 08:01:34 -04:00

439 lines
14 KiB
Python

"""Certificates API
This is a Python API for generating certificates asynchronously.
Other Django apps should use the API functions defined in this module
rather than importing Django models directly.
"""
import logging
from django.conf import settings
from django.core.urlresolvers import reverse
from eventtracking import tracker
from opaque_keys.edx.keys import CourseKey
from openedx.core.djangoapps.content.course_overviews.models import CourseOverview
from xmodule.modulestore.django import modulestore
from util.organizations_helpers import get_course_organizations
from certificates.models import (
CertificateStatuses,
certificate_status_for_student,
CertificateGenerationCourseSetting,
CertificateGenerationConfiguration,
ExampleCertificateSet,
GeneratedCertificate,
CertificateTemplate,
)
from certificates.queue import XQueueCertInterface
log = logging.getLogger("edx.certificate")
def get_certificates_for_user(username):
"""
Retrieve certificate information for a particular user.
Arguments:
username (unicode): The identifier of the user.
Returns: list
Example Usage:
>>> get_certificates_for_user("bob")
[
{
"username": "bob",
"course_key": "edX/DemoX/Demo_Course",
"type": "verified",
"status": "downloadable",
"download_url": "http://www.example.com/cert.pdf",
"grade": "0.98",
"created": 2015-07-31T00:00:00Z,
"modified": 2015-07-31T00:00:00Z
}
]
"""
return [
{
"username": username,
"course_key": cert.course_id,
"type": cert.mode,
"status": cert.status,
"grade": cert.grade,
"created": cert.created_date,
"modified": cert.modified_date,
# NOTE: the download URL is not currently being set for webview certificates.
# In the future, we can update this to construct a URL to the webview certificate
# for courses that have this feature enabled.
"download_url": (
cert.download_url
if cert.status == CertificateStatuses.downloadable
else None
),
}
for cert in GeneratedCertificate.objects.filter(user__username=username).order_by("course_id")
]
def generate_user_certificates(student, course_key, course=None, insecure=False, generation_mode='batch',
forced_grade=None):
"""
It will add the add-cert request into the xqueue.
A new record will be created to track the certificate
generation task. If an error occurs while adding the certificate
to the queue, the task will have status 'error'. It also emits
`edx.certificate.created` event for analytics.
Args:
student (User)
course_key (CourseKey)
Keyword Arguments:
course (Course): Optionally provide the course object; if not provided
it will be loaded.
insecure - (Boolean)
generation_mode - who has requested certificate generation. Its value should `batch`
in case of django command and `self` if student initiated the request.
forced_grade - a string indicating to replace grade parameter. if present grading
will be skipped.
"""
xqueue = XQueueCertInterface()
if insecure:
xqueue.use_https = False
generate_pdf = not has_html_certificates_enabled(course_key, course)
status, cert = xqueue.add_cert(student, course_key,
course=course,
generate_pdf=generate_pdf,
forced_grade=forced_grade)
if status in [CertificateStatuses.generating, CertificateStatuses.downloadable]:
emit_certificate_event('created', student, course_key, course, {
'user_id': student.id,
'course_id': unicode(course_key),
'certificate_id': cert.verify_uuid,
'enrollment_mode': cert.mode,
'generation_mode': generation_mode
})
return status
def regenerate_user_certificates(student, course_key, course=None,
forced_grade=None, template_file=None, insecure=False):
"""
It will add the regen-cert request into the xqueue.
A new record will be created to track the certificate
generation task. If an error occurs while adding the certificate
to the queue, the task will have status 'error'.
Args:
student (User)
course_key (CourseKey)
Keyword Arguments:
course (Course): Optionally provide the course object; if not provided
it will be loaded.
grade_value - The grade string, such as "Distinction"
template_file - The template file used to render this certificate
insecure - (Boolean)
"""
xqueue = XQueueCertInterface()
if insecure:
xqueue.use_https = False
generate_pdf = not has_html_certificates_enabled(course_key, course)
return xqueue.regen_cert(
student,
course_key,
course=course,
forced_grade=forced_grade,
template_file=template_file,
generate_pdf=generate_pdf
)
def certificate_downloadable_status(student, course_key):
"""
Check the student existing certificates against a given course.
if status is not generating and not downloadable or error then user can view the generate button.
Args:
student (user object): logged-in user
course_key (CourseKey): ID associated with the course
Returns:
Dict containing student passed status also download url for cert if available
"""
current_status = certificate_status_for_student(student, course_key)
# If the certificate status is an error user should view that status is "generating".
# On the back-end, need to monitor those errors and re-submit the task.
response_data = {
'is_downloadable': False,
'is_generating': True if current_status['status'] in [CertificateStatuses.generating,
CertificateStatuses.error] else False,
'download_url': None
}
if current_status['status'] == CertificateStatuses.downloadable:
response_data['is_downloadable'] = True
response_data['download_url'] = current_status['download_url']
return response_data
def set_cert_generation_enabled(course_key, is_enabled):
"""Enable or disable self-generated certificates for a course.
There are two "switches" that control whether self-generated certificates
are enabled for a course:
1) Whether the self-generated certificates feature is enabled.
2) Whether self-generated certificates have been enabled for this particular course.
The second flag should be enabled *only* when someone has successfully
generated example certificates for the course. This helps avoid
configuration errors (for example, not having a template configured
for the course installed on the workers). The UI for the instructor
dashboard enforces this constraint.
Arguments:
course_key (CourseKey): The course identifier.
Keyword Arguments:
is_enabled (boolean): If provided, enable/disable self-generated
certificates for this course.
"""
CertificateGenerationCourseSetting.set_enabled_for_course(course_key, is_enabled)
cert_event_type = 'enabled' if is_enabled else 'disabled'
event_name = '.'.join(['edx', 'certificate', 'generation', cert_event_type])
tracker.emit(event_name, {
'course_id': unicode(course_key),
})
if is_enabled:
log.info(u"Enabled self-generated certificates for course '%s'.", unicode(course_key))
else:
log.info(u"Disabled self-generated certificates for course '%s'.", unicode(course_key))
def cert_generation_enabled(course_key):
"""Check whether certificate generation is enabled for a course.
There are two "switches" that control whether self-generated certificates
are enabled for a course:
1) Whether the self-generated certificates feature is enabled.
2) Whether self-generated certificates have been enabled for this particular course.
Certificates are enabled for a course only when both switches
are set to True.
Arguments:
course_key (CourseKey): The course identifier.
Returns:
boolean: Whether self-generated certificates are enabled
for the course.
"""
return (
CertificateGenerationConfiguration.current().enabled and
CertificateGenerationCourseSetting.is_enabled_for_course(course_key)
)
def generate_example_certificates(course_key):
"""Generate example certificates for a course.
Example certificates are used to validate that certificates
are configured correctly for the course. Staff members can
view the example certificates before enabling
the self-generated certificates button for students.
Several example certificates may be generated for a course.
For example, if a course offers both verified and honor certificates,
examples of both types of certificate will be generated.
If an error occurs while starting the certificate generation
job, the errors will be recorded in the database and
can be retrieved using `example_certificate_status()`.
Arguments:
course_key (CourseKey): The course identifier.
Returns:
None
"""
xqueue = XQueueCertInterface()
for cert in ExampleCertificateSet.create_example_set(course_key):
xqueue.add_example_cert(cert)
def has_html_certificates_enabled(course_key, course=None):
"""
Determine if a course has html certificates enabled.
Arguments:
course_key (CourseKey|str): A course key or a string representation
of one.
course (CourseDescriptor|CourseOverview): A course.
"""
html_certificates_enabled = False
try:
if not isinstance(course_key, CourseKey):
course_key = CourseKey.from_string(course_key)
course = course if course else CourseOverview.get_from_id(course_key)
if settings.FEATURES.get('CERTIFICATES_HTML_VIEW', False) and course.cert_html_view_enabled:
html_certificates_enabled = True
except: # pylint: disable=bare-except
pass
return html_certificates_enabled
def example_certificates_status(course_key):
"""Check the status of example certificates for a course.
This will check the *latest* example certificate task.
This is generally what we care about in terms of enabling/disabling
self-generated certificates for a course.
Arguments:
course_key (CourseKey): The course identifier.
Returns:
list
Example Usage:
>>> from certificates import api as certs_api
>>> certs_api.example_certificate_status(course_key)
[
{
'description': 'honor',
'status': 'success',
'download_url': 'http://www.example.com/abcd/honor_cert.pdf'
},
{
'description': 'verified',
'status': 'error',
'error_reason': 'No template found!'
}
]
"""
return ExampleCertificateSet.latest_status(course_key)
def get_certificate_url(user_id, course_id):
"""
:return certificate url
"""
url = ""
if settings.FEATURES.get('CERTIFICATES_HTML_VIEW', False):
url = reverse(
'certificates:html_view',
kwargs={
"user_id": str(user_id),
"course_id": unicode(course_id),
}
)
else:
try:
if isinstance(course_id, basestring):
course_id = CourseKey.from_string(course_id)
user_certificate = GeneratedCertificate.objects.get(
user=user_id,
course_id=course_id
)
url = user_certificate.download_url
except GeneratedCertificate.DoesNotExist:
log.critical(
'Unable to lookup certificate\n'
'user id: %d\n'
'course: %s', user_id, unicode(course_id)
)
return url
def get_active_web_certificate(course, is_preview_mode=None):
"""
Retrieves the active web certificate configuration for the specified course
"""
certificates = getattr(course, 'certificates', '{}')
configurations = certificates.get('certificates', [])
for config in configurations:
if config.get('is_active') or is_preview_mode:
return config
return None
def get_certificate_template(course_key, mode):
"""
Retrieves the custom certificate template based on course_key and mode.
"""
org_id, template = None, None
# fetch organization of the course
course_organization = get_course_organizations(course_key)
if course_organization:
org_id = course_organization[0]['id']
if org_id and mode:
template = CertificateTemplate.objects.filter(
organization_id=org_id,
course_key=course_key,
mode=mode,
is_active=True
)
# if don't template find by org and mode
if not template and org_id and mode:
template = CertificateTemplate.objects.filter(
organization_id=org_id,
mode=mode,
is_active=True
)
# if don't template find by only org
if not template and org_id:
template = CertificateTemplate.objects.filter(
organization_id=org_id,
is_active=True
)
# if we still don't template find by only course mode
if not template and mode:
template = CertificateTemplate.objects.filter(
mode=mode,
is_active=True
)
return template[0].template if template else None
def emit_certificate_event(event_name, user, course_id, course=None, event_data=None):
"""
Emits certificate event.
"""
event_name = '.'.join(['edx', 'certificate', event_name])
if course is None:
course = modulestore().get_course(course_id, depth=0)
context = {
'org_id': course.org,
'course_id': unicode(course_id)
}
data = {
'user_id': user.id,
'course_id': unicode(course_id),
'certificate_url': get_certificate_url(user.id, course_id)
}
event_data = event_data or {}
event_data.update(data)
with tracker.get_tracker().context(event_name, context):
tracker.emit(event_name, event_data)