TDISCUS

This is a Tsugi Threaded Discussion Tool. It is intended to be a flexible backend with at least one UI but ready to support many different UI's.

Installation

You can install this as a module using the administration interface on your tsugi server, or just check it out into your mod folder.

Of course once you check it out, run the database upgrade from the admin UI or from the command line:

cd tsugi/admin
php upgrade.php

At this point it is a launchable tool and you can play with it in in the test environment like

https://www.wa4e.com/tsugi/store/

This test environment is great as it allows you to see both the instructor and several student views with test data all setup.

Use in lessons.json

You can add discussion entries into your lessons.json. You can add course-wide discussions at the top-level in the JSON:

"discussions" : [
    {
    "title" : "Welcome to Python for Everybody",
    "launch" : "mod/tdiscus/",
    "resource_link_id": "discussion_welcome"
    }
],
"modules": [
    ...

The format of a discussions entry is the same as an lti entry.

You can add one or more discussions to a module entry at the same level as an lti entry and using the same format. Of course make sure to keep resource_link_id values unique across the whole file.

"discussions" : [
    {
    "title" : "Hello World module",
    "launch" : "mod/tdiscus/",
    "resource_link_id": "discuss_01_hello"
    }
],
"lti" : [
    ...

Enabling tdiscus in config.php

You need to enable discussions in your tsugi/config.php by adding the following line:

$CFG->tdiscus = true;

This configuration is needed to keep Tsugi from having to look through the mod folder to see if tdisucs is installed.

Course-wide link to all discussions

If you are running a site with lessons.json you are using Koseu to make the lessons UI appear under the /lessons URL. There is a course wide disucssions tool automatically available at the /discussions URL. For example:

https://www.py4e.com/discussions

This tool works whether or not the session is logged in. If the user is not logged in the sessions are shown but cannot be entered.

History

What's in a name? The https://www.tdiscus.com/ domain was available when the project was started back in 2017.

This project was in tsugicontrib from 2017 through 2020 with a data model and minimal experimental JSON + Handlebars UI prototype. Over the holiday break 2020, the project went from prototype to MVP in six days. This is nice because in many ways a threaded discussion tool was the last big gap in Tsugi covering all the core use cases for an LMS.

TODO

This is a very early product. Its MVP UI is very much modelled after the Coursera threaded disussion tool because its features have a nod towards the scalable / MOOCs use cases.

The goals of the data model are pretty lofty - the idea is to support a wide range of UI's and pedagogies. If you look at the Settings in the tool you will see a lot of checkboxes - there will be a lot more by the time it is done.

Features yet to be added:

• The ability to get email updates when a comment is added to a thread.

• Image uploading into thread text. I added a feature to Tsugi's blob storage to improve the ability to delete unreferences images from the Tsugi single-instance blob store. I want to make sure this works really well before I let thread creators upload pictures.

• Rich text editor for comments. Right now for simplicity the current version uses server-based HTML cleaining using the http://htmlpurifier.org/ library, and does cleaning as data is presented. To avoid performance problems we don't enable the RTE for comments. But this could be done in-bound without too much effort. There are already cleaned fields in the tdiscus_thread and tdiscus_comment tables to allow for a flexible evolution on this front.

• Allow for version tracking and student editing of the thread text. This is a way to meet some Piazza-unique use cases which will likely be useful in general for various pedagogies. The verion tracking will be done in a general way and at some point version trcking will be added to the CKEditor tool.

In the long term there is a dream of a Piazza-style UI and Slack-style UI using this back-end - but that will require some UI / UI design talent that I do not posess.

References

http://htmlpurifier.org/

https://stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/192462#192462

https://www.slideshare.net/billkarwin/models-for-hierarchical-data

https://stackoverflow.com/questions/8252323/mysql-closure-table-hierarchical-database-how-to-pull-information-out-in-the-c