Drag and Drop XBlock v2

This XBlock implements a friendly drag-and-drop style problem, where the learner has to drag items to zones on a target image.

The editor is fully guided. Features include:

• custom target image
• free target zone positioning and sizing
• custom zone labels
• ability to show or hide zone borders
• custom text and background colors for items
• auto-alignment for items: left, right, center
• image items
• decoy items that don't have a zone
• feedback popups for both correct and incorrect attempts
• introductory and final feedback

The XBlock supports progressive grading and keeps progress across refreshes. All checking and record keeping is done on the server side.

The following screenshot shows the Drag and Drop XBlock rendered inside the edX LMS before the user starts solving the problem:

This screenshot shows the XBlock after the learner successfully completed the Drag and Drop problem:

Installation

Install the requirements into the Python virtual environment of your edx-platform installation by running the following command from the root folder:

$ pip install -r requirements.txt

Theming

The Drag and Drop XBlock ships with an alternate theme called "Apros" that you can enable by adding the following entry to XBLOCK_SETTINGS in lms.env.json:

        "drag-and-drop-v2": {
            "theme": {
                "package": "drag_and_drop_v2",
                "locations": ["public/themes/apros.css"]
            }
        }

You can use the same approach to apply a custom theme:

"package" can refer to any Python package in your virtualenv, which means you can develop and maintain your own theme in a separate package. There is no need to fork or modify this repository in any way to customize the look and feel of your Drag and Drop problems.

"locations" is a list of relative paths pointing to CSS files belonging to your theme. While the XBlock loads, files will be added to it in the order that they appear in this list. (This means that if there are rules with identical selectors spread out over different files, rules in files that appear later in the list will take precedence over those that appear earlier.)

Finally, note that the default (unthemed) appearance of the Drag and Drop XBlock has been optimized for accessibility, so its use is encouraged -- especially for courses targeting large and/or potentially diverse audiences.

Enabling in Studio

Drag and Drop v2 XBlock is already included in Open edX.

You will find it in "Add New Component" box in Studio: click the green Problem button, choose the the Advanced tab and choose Drag and Drop.

Usage

The Drag and Drop XBlock features an interactive editor. Add the Drag and Drop component to a lesson, then click the EDIT button.

In the first step, you can set some basic properties of the component, such as the title, the problem mode, the maximum number of attempts, the maximum score, the problem text to render above the background image, the introductory feedback (shown initially), and the final feedback (shown after the learner successfully completes the drag and drop problem, or when the learner runs out of attempts).

There are two problem modes available:

• Standard: In this mode, the learner gets immediate feedback on each attempt to place an item, and the number of attempts is not limited.
• Assessment: In this mode, the learner places all items on the board and then clicks a "Submit" button to get feedback.
  • The number of attempts can be limited.
  • The learner can click a "Show Answer" button to temporarily place items on their correct drop zones.
    You can select one of the pre-defined conditions for displaying this button. They work in the same way as in the Problem XBlock, so you can read about each them in the Problem Component documentation.
    By default, the value from the course "Advanced Settings" configuration is used. If you have modified this for a specific XBlock but want to switch back to using the default value, select the "Default" option.

In the next step, you set the URL and description for the background image and define the properties of the drop zones. For each zone you can specify the text that should be rendered inside it (the "zone label"), how wide and tall it should be, and where it should be placed on the background image. In this step you can also specify whether you would like zone labels to be shown to learners or not, as well as whether or not to display borders outlining the zones. It is possible to define an arbitrary number of drop zones as long as their labels are unique.

You can specify the alignment for items once they are dropped in the zone. Centered alignment is the default, and places items from top to bottom along the center of the zone. Left alignment causes dropped items to be placed from left to right across the zone. Right alignment causes the items to be placed from right to left across the zone. Items dropped in a zone will not overlap, but if the zone is not made large enough for all its items, they will overflow the bottom of the zone, and potentially overlap the zones below.

In the final step, you define the background and text color for drag items, as well as the drag items themselves. A drag item can contain either text or an image. You can define custom success and error feedback for each item. In standard mode, the feedback text is displayed in a popup after the learner drops the item on a zone - the success feedback is shown if the item is dropped on a correct zone, while the error feedback is shown when dropping the item on an incorrect drop zone. In assessment mode, the success feedback texts are not used, while error feedback texts are shown when learner submits a solution.

You can select any number of zones for an item to belong to using the checkboxes; all zones defined in the previous step are available. You can leave all of the checkboxes unchecked in order to create a "decoy" item that doesn't belong to any zone.

You can define an arbitrary number of drag items, each of which may be attached to any number of zones.

"Maximum items per Zone" setting controls how many items can be dropped into a single zone, allowing some degree of control over items overlapping zones below.

Scoring

Student assessment scores for the Drag and Drop XBlock are calculated according to the following formula:

score = (C + D) / T

Where C is the number of correctly placed regular items, D is the number of decoy items that were correctly left unplaced, and T is the total number of items available.

Example: consider a Drag and Drop instance configured with a total of four items, of which three are regular items and one is a decoy. If a learner places two of the normal items correctly and one incorrectly (C = 2), and wrongly places the decoy item onto a drop zone (D = 0), that learner's score will be 50%, as given by:

score = (2 + 0) / 4

If the learner were to then move the decoy item back to the bank (D = 1) and move the wrongly placed regular item to the correct dropzone (C = 3), their score would be 100%:

score = (3 + 1) / 4

Optionally, there is an alternative grading that can be enabled, by setting the waffle flag drag_and_drop_v2.grading_ignore_decoys, which will drop the decoy items entirely from the score calculation. The formula will change to:

score = C / R

Where C is the number of correctly placed regular items, R is the number of required regular items.

Demo Course

Export of a demo course that showcases various Drag and Drop v2 features is available at github.com/open-craft/demo-courses/archive/drag-and-drop-v2.tar.gz.

Analytics Events

The following analytics events are provided by this block.

edx.drag_and_drop_v2.loaded

Fired when the Drag and Drop XBlock is finished loading.

Example ("common" fields that are not interesting in this context have been left out):

{
...
    "event": {},
    "event_source": "server",                              --  Common field, contains event source.
    "event_type": "edx.drag_and_drop_v2.loaded",           --  Common field, contains event name.
...

Real event example (taken from a devstack):

{
    "username": "staff",
    "event_type": "edx.drag_and_drop_v2.loaded",
    "ip": "10.0.2.2",
    "agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0",
    "host": "precise64",
    "referer": "http://example.com/courses/course-v1:DnD+DnD+DnD/courseware/ec546c58d2f447b7a9223c57b5de7344/756071f8de7f47c3b0ae726586ebbe16/1?activate_block_id=block-v1%3ADnD%2BDnD%2BDnD%2Btype%40vertical%2Bblock%40d2fc47476ca14c55816c4a1264a27280",
    "accept_language": "en;q=1.0, en;q=0.5",
    "event": {},
    "event_source": "server",
    "context": {
        "course_user_tags": {},
        "user_id": 5,
        "org_id": "DnD",
        "module": {
            "usage_key": "block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3",
            "display_name": "Drag and Drop"
        },
        "course_id": "course-v1:DnD+DnD+DnD",
        "path": "/courses/course-v1:DnD+DnD+DnD/xblock/block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3/handler/publish_event"
    },
    "time": "2016-01-13T01:52:41.330049+00:00",
    "page": "x_module"
}

edx.drag_and_drop_v2.item.picked_up

Fired when a learner picks up a draggable item.

Example ("common" fields that are not interesting in this context have been left out):

{
...
    "event": {
      "item_id": 0,                                        --  ID of the draggable item.
    },
    "event_source": "server",                              --  Common field, contains event source.
    "event_type": "edx.drag_and_drop_v2.picked_up",        --  Common field, contains event name.
...

Real event example (taken from a devstack):

{
    "username": "staff",
    "event_type": "edx.drag_and_drop_v2.item.picked_up",
    "ip": "10.0.2.2",
    "agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0",
    "host": "precise64",
    "referer": "http://example.com/courses/course-v1:DnD+DnD+DnD/courseware/ec546c58d2f447b7a9223c57b5de7344/756071f8de7f47c3b0ae726586ebbe16/1?activate_block_id=block-v1%3ADnD%2BDnD%2BDnD%2Btype%40vertical%2Bblock%40d2fc47476ca14c55816c4a1264a27280",
    "accept_language": "en;q=1.0, en;q=0.5",
    "event": {
        "item_id": 0,
    },
    "event_source": "server",
    "context": {
        "course_user_tags": {},
        "user_id": 5,
        "org_id": "DnD",
        "module": {
            "usage_key": "block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3",
            "display_name": "Drag and Drop"
        },
        "course_id": "course-v1:DnD+DnD+DnD",
        "path": "/courses/course-v1:DnD+DnD+DnD/xblock/block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3/handler/publish_event"
    },
    "time": "2016-01-13T01:58:44.395935+00:00",
    "page": "x_module"
}

edx.drag_and_drop_v2.item.dropped

Fired when a learner drops a draggable item.

This event will be emitted when a learner drops a draggable item.

Example ("common" fields that are not interesting in this context have been left out):

{
...
    "event": {
      "is_correct": true,                                  --  Whether the draggable item has been placed in the correct location.
      "item": "Goes to the top",                           --  Name, or in the absence thereof, image URL of the draggable item.
      "item_id": 0,                                        --  ID of the draggable item.
      "location": "The Top Zone",                          --  Name of the location the item was dragged to.
      "location_id": 1,                                    --  ID of the location the item was dragged to.
    },
    "event_source": "server",                              --  Common field, contains event source.
    "event_type": "edx.drag_and_drop_v2.dropped",          --  Common field, contains event name.
...

Real event example (taken from a devstack):

{
    "username": "staff",
    "event_type": "edx.drag_and_drop_v2.item.dropped",
    "ip": "10.0.2.2",
    "agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0",
    "host": "precise64",
    "referer": "http://example.com/courses/course-v1:DnD+DnD+DnD/courseware/ec546c58d2f447b7a9223c57b5de7344/756071f8de7f47c3b0ae726586ebbe16/1?activate_block_id=block-v1%3ADnD%2BDnD%2BDnD%2Btype%40vertical%2Bblock%40d2fc47476ca14c55816c4a1264a27280",
    "accept_language": "en;q=1.0, en;q=0.5",
    "event": {
        "is_correct": true,
        "location": "The Top Zone",
        "location_id": 1,
        "item": "Goes to the top",
        "item_id": 0,
    },
    "event_source": "server",
    "context": {
        "course_user_tags": {},
        "user_id": 5,
        "org_id": "DnD",
        "module": {
            "usage_key": "block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3",
            "display_name": "Drag and Drop"
        },
        "course_id": "course-v1:DnD+DnD+DnD",
        "path": "/courses/course-v1:DnD+DnD+DnD/xblock/block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3/handler/do_attempt"
    },
    "time": "2016-01-13T01:58:45.202313+00:00",
    "page": "x_module"
}

edx.drag_and_drop_v2.feedback.opened

Fired when the feedback pop-up is opened.

Example ("common" fields that are not interesting in this context have been left out):

{
...
    "event": {
      "content": "Correct! This one belongs to The Top Zone.",  --  Content of the feedback popup.
      "truncated": false,                                       --  Boolean indicating whether "content" field was truncated.
    },
    "event_source": "server",                                   --  Common field, contains event source.
    "event_type": "edx.drag_and_drop_v2.feedback.opened",       --  Common field, contains event name.
...

Real event example (taken from a devstack):

{
    "username": "staff",
    "event_type": "edx.drag_and_drop_v2.feedback.opened",
    "ip": "10.0.2.2",
    "agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0",
    "host": "precise64",
    "referer": "http://example.com/courses/course-v1:DnD+DnD+DnD/courseware/ec546c58d2f447b7a9223c57b5de7344/756071f8de7f47c3b0ae726586ebbe16/1?activate_block_id=block-v1%3ADnD%2BDnD%2BDnD%2Btype%40vertical%2Bblock%40d2fc47476ca14c55816c4a1264a27280",
    "accept_language": "en;q=1.0, en;q=0.5",
    "event": {
        "content": "Correct! This one belongs to The Top Zone.",
        "truncated": false,
    },
    "event_source": "server",
    "context": {
        "course_user_tags": {},
        "user_id": 5,
        "org_id": "DnD",
        "module": {
            "usage_key": "block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3",
            "display_name": "Drag and Drop"
        },
        "course_id": "course-v1:DnD+DnD+DnD",
        "path": "/courses/course-v1:DnD+DnD+DnD/xblock/block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@6b80ce1e8b78426898b47a834d72ffd3/handler/publish_event"
    },
    "time": "2016-01-13T01:58:45.844986+00:00",
    "page": "x_module"
}

edx.drag_and_drop_v2.feedback.closed

Fired when the feedback popup is closed.

Example ("common" fields that are not interesting in this context have been left out):

{
...
    "event": {
      "content": "No, this item does not belong here. Try again." --  Message of the feedback popup that was closed.
      "manually": true,                                           --  Whether or not the user closed the feedback window manually or if it was auto-closed.
      "truncated": false,                                         --  Boolean indicating whether "content" field was truncated.
    },
    "event_source": "server",                                     --  Common field, contains event source.
    "event_type": "edx.drag_and_drop_v2.feedback.closed",         --  Common field, contains event name.
...

Real event example (taken from a devstack):

{
    "username": "staff",
    "event_type": "edx.drag_and_drop_v2.feedback.closed",
    "ip": "10.0.2.2",
    "agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:43.0) Gecko/20100101 Firefox/43.0",
    "host": "precise64",
    "referer": "http://example.com/courses/course-v1:DnD+DnD+DnD/courseware/ec546c58d2f447b7a9223c57b5de7344/756071f8de7f47c3b0ae726586ebbe16/1?activate_block_id=block-v1%3ADnD%2BDnD%2BDnD%2Btype%40vertical%2Bblock%40d2fc47476ca14c55816c4a1264a27280",
    "accept_language": "en;q=1.0, en;q=0.5",
    "event": {
        "content": "No, this item does not belong here. Try again."
        "manually": true
        "truncated": false,
    },
    "event_source": "server",
    "context": {
        "course_user_tags": {},
        "user_id": 5,
        "org_id": "DnD",
        "module": {
            "usage_key": "block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@13d1b859a2304c858e1810ccc23f29b2",
            "display_name": "Drag and Drop"
        },
        "course_id": "course-v1:DnD+DnD+DnD",
        "path": "/courses/course-v1:DnD+DnD+DnD/xblock/block-v1:DnD+DnD+DnD+type@drag-and-drop-v2+block@13d1b859a2304c858e1810ccc23f29b2/handler/publish_event"
    },
    "time": "2016-01-13T02:07:00.988534+00:00",
    "page": "x_module"
}

Testing with tox

Inside a fresh virtualenv, cd into the root folder of this repository (xblock-drag-and-drop-v2) and run:

$ make requirements

You can then run the entire test suite via:

$ make test

To run specific test groups, use one of the following commands:

$ make test.unit
$ make test.quality
$ make test.translations

To run individual unit tests, use:

$ make test.unit TEST=tests/unit/test_basics.py::BasicTests::test_student_view_data

Manual testing (without tox)

To run tests without tox, use:

$ make requirements_python
$ make test.python TEST=tests/unit/test_basics.py::BasicTests::test_student_view_data

i18n compatibility

According to edX docs on XBlock i18n, LMS runtime is capable of supporting XBlock i18n and l10n. To comply with l10n requirements, XBlock is supposed to provide translations in xblock_package_root/translations/locale_code/LC_MESSAGES/text.po folder in GNU Gettext Portable Object file format.

Drag and Drop v2 XBlock aims to comply with i18n requirements for Open edX platform, including a stricter set of requirements for edx.org itself, thus providing the required files. So far only two translations are available:

• Default English translation
• Fake "Esperanto" translation used to test i18n/l10n.

Updates to translated strings are supposed to be propagated to text.po files. EdX i18n_tools is used here along GNU Gettext and a Makefile for automation.

Note: currently translations directory is a symbolic link to conf/locale directory. Also, 'text.po' file for locale code en is a symbolic link to conf/locale/en/LC_MESSAGES/django.po file. Both links works as a transition step to fully moving translation files to openedx-translations repository

Translatable strings

$ make extract_translations

Note that this command generates text.po which is supposed to contain all translatable strings.

To check if text.po is correct, one can run:

$ make compile_translations

If everything is correct, it will create translations/en/LC_MESSAGES/text.mo and locale/en/LC_MESSAGES/text.js files.

Building fake "Esperanto" translation

As previously said, this fake translation mainly exists for testing reasons. For edX platform it is built using Dummy translator from edX i18n-tools.

$ make dummy_translations

Native API

Further information on the API for native mobile applications can be found here.

Releasing

To release a new version, update .travis.yml and setup.py to point to your new intended version number and create a new release with that version tag via Github.