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New Feature
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Resolution: Fixed
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Minor
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1.9.9
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None
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MOODLE_19_STABLE
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MOODLE_19_STABLE
The enrol_shebang module is used to import Banner/LMB course, person, and enrollment messages into Moodle. It is still in beta and being tested. The README.txt file contents are pasted below.
README.txt for SHEBanG enrolment plugin/module
DISCLAIMER AND LICENSING
------------------------
SHEBanG enrolment plugin/module for SunGard HE Banner(r) data import
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
GENERAL INFORMATION
-------------------
The SHEBanG enrolment plugin is designed to import Luminis Message
Broker (LMB) messages containing data sent from a SunGard HE Banner
installation. The messages are POSTed by LMB to a specified URL;
that URL should end up resolving to enrol/shebang/secure/post.php
either by means of direct address, symbolic link, or Apache server
configuration (e.g. alias). An alternate method of import is the
file upload feature.
There already is an enrolment plugin, LMB, developed by Eric Merrill
<merrill@oakland.edu> that processes Banner data, and has many more
configuration options and features. We have been using this plugin
for several years at Appalachian State with only a few basic alter-
ations.
So why write a new one? Why reinvent? There were a few reasons.
In our particular installtion of Banner/LMB, we kept getting several
essentially identical messages which resulted in duplicate rows in
one of the staging tables. Normally not a big problem, but eventually
the staging table becomes bloated with duplicates. We also wanted to
log each of the XML messages received, but not in the database.
Putting them in a text file is more practical for us. Messages sent
by the LMB are logged to the file-system in the Moodle data directory
rather than the database; this message log file is locked while the
message is being processed in order to serialize message processing.
In the case where additional data from the XML message was needed, a
regular expression had to be added--most often this is simple enough
given an existing pattern from which to start, but in some instances
where the message format changes ever so slightly (e.g. recstatus),
it makes more sense to use DOMXPath queries to extract message data.
XMLParser is used to break up the input, whether from file or posted
XML, into the principle elements we want (<group>, <person>, and
<membership>), and from that point use the DOMDocument and DOMXPath
to query for the needed values.
Some other differences:
Messages imported from a file are not logged since there's already a
source file;
A cross-list course parent is created only when the first <membership>
message for that cross-list arrives, and then it will be created by
making a copy of the child course.
The Moodle user's idnumber column is populated with the SCTID/Banner
userid, rather than the Luminis sourcedid/id.
The only cron activity is the monitor for last message arrival time.
Some Moodle sites may have a very frequent cron activity (5-10 min)
so it didn't seem practical to put dir/file check tasks in a common
script--rather use a dedicated cron task, if needed at all, for the
Banner extract/batch-file imports.
INSTALLATION
------------
Place the shebang directory in the site's enrol directory. Access the
notifications page (Admin block->Notifications) to initiate database
setup.
Enable and configure the plugin (Courses->Enrolments->SHEBanG[Edit]).
Configure your Banner/LMB to POST messages to the URL corresponding
to the enrol/shebang/secure/post.php file, for example:
http://moodle.someuniversity.edu/enrol/shebang/secure/post.php
- * * * * * * * * I M P O R T A N T * * * * * * * * *
THIS URL NEEDS TO BE SECURED IN SOME FASHION TO PREVENT UNAUTHORIZED
USERS FROM INJECTING ERRANT DATA INTO YOUR DATABASE. THE METHODS FOR
SECURING THIS URL INCLUDE, BUT ARE NOT LIMITED TO, APACHE HTTP AUTH
CONFIGURED-IDEALLY WITH SSL-AT THE SERVER/VHOST/DIRECTORY LEVEL OR
WITH AN .htaccess FILE. ANOTHER OPTION, IS TO USE THE AUTHENTICATION
FEATURE IN THE MODULE, BUT AGAIN IT IS STRONGLY RECOMMENDED TO USE A
SECURE SOCKET CONNECTION IN ADDITION TO HTTP BASIC OR DIGEST AUTHEN-
TICATION SINCE EITHER THE USERID/PWD INFORMATION WILL BE EXPOSED
WHEN SENT IN CLEAR-TEXT (BASIC) OR THE (DIGEST) HASH WILL BE EXPOSED.
There is no Moodle authentication protection in the post.php since it
is intended that only Banner LMB will be accessing this URL and a
separate userid/password will be configured by the Moodle server admin
and shared with the Luminis admins.
CONSIDERATIONS FOR BLOCKING ISSUES
----------------------------------
Because SHEBanG serializes message processing using a file lock, it
is possible, in some cases likely, that a blocking bottleneck will
take place when a large number of messages are sent by Banner/LMB at
or near the same time. To mitigate the risk of the all the Apache
worker processes being occupied and blocked, and thus freezing out
the application end-users, consider setting up another Apache daemon
to handle LMB messages exclusively on an alternate port such as 8080.
In this way you can tailor the configured number of initial, max-min
spare worker processes, etc., and if these processes should become
consumed, the end-users will not be impacted.
HOW ENTITIES ARE ASSOICATED AND REFERENCED
------------------------------------------
Courses:
A staging record in the [mdl_enrol_shebang_section] table is inserted
or updated, using the <sourcedid><id> value (the CRN) as the alternate
key. This same value is placed in the [mdl_course](idnumber) column so
that table can be queried directory. The course's (idnumber) value can
not be changed after that or the association will be lost.
Users:
A staging record in the [mdl_enrol_shebang_person] table is inserted
or updated, using the <sourcedid><id> value (the Luminis Id for that
Banner identity, distinct from the Banner identity value). Susbsequent
<membership> messages for this person will use this <sourcedid><id> so
we need to use this as an alternate identifying key value. A <person>
message also contains the <userid useridtype="SCTID"> value, the
Banner identity, and it's this value that is placed in the [mdl_user]
(idnumber) column.
So, upon arrival of a <person> message, and after the staging record
is handled, the [mdl_user] table is queried on the (idnumber) column
for the SCTID value--if no record is found, then an attempt is made to
insert one, otherwise the found record is updated. Because other
columns in the [mdl_user] table are unique (enforced either by the
application or the database), a collision on email or username by
prevent the insert. In such cases, manual inspection of the existing
user account should be done to determine if it can be deleted (no
access, no enrolments, etc.) or if it should be associated with the
corresponding [mdl_enrol_shebang_person] row by placing the appro-
priate Banner identity value in the user's (idnumber) column.
Until any such collision is resolved, course enrollments for that
person/user will fail since no association exists between the person
entity and the user entity.
- will be (partly) resolved by
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MDLSITE-1030 developer page not shown AND "CVS admin" button not working
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- Closed
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