This preset was developed on the use case to get a ranking of a list of items. In this special case there is a list of party games, proposed by team members and the team should pick the favourit game from the list. Each user has three choices which are mandatory. The user may pick one item as the first choice (awarded by 3 points), one item as a second choice (awarded by 2 points) and another item as the third choice (awarded by one point).
The result is a sorted list of items ordered from top with the most points down to bottom with the least points received.
This database activity makes sense of being the only one in a "single activity" course format.
The database fields consist of the three choices. Each dataset represents a pick
of a user where he makes his preferred choices on the items. Each field is a
number field, containing the item number that was choosen in that rank. To sum
up the result, the items in choice_first are multiplied by 3, the items in
choice_second by two and the items in choice_third are multiplied by one.
In the activity itself it probably makes sense to have the entries setup in the way that each one can enter one entry only, and results should be shown after the entry has been added.
The list of items is defined in the Custom JavaScript template along with functions to display the information in the other templates, mainly adding and displaying one entry as well as displaying the list of all entries.
From the field list, the description is used as well. It is displayed in the selection list in the Add entry template.
The fields itself are set as hidden fields in the Add entry template which are filled by the selection when the button "Save" button is hit in the add entry page. Because the fields are mandatory, the user needs to provide three picks. If none is provided, Moodle shows an error message telling that no field has been filled out. If there is at least one choice provided but not all, nothing happens, the user gets back the the entry page without an error message.
The items can be defined and configured in the Custom JavaScript template.
In this example, an item consists of two properties:
{
name: "Item name to choose",
user: "Some other information for that item"
}
Remove or add items as you wish, as long as you have no datasets (e.g. votes) yet.
This list is used to build up a list consisting of the item information and
a selection for the preferred choice. This is done via the function
displayChoices(). That function makes use of the template variable
TMPL_INPUT_ENTRY.
In the same way the ranking of all choices is displayed. This is done via
the function displayVotes() and the template variable TMPL_LIST_ENTRY.
When displaying the results, the votes must be submitted to that function.
This is done in the List view template. Each entry looks like this:
[ 3, 5, 1]
This code means the users first choice was item number 4, second choice was item number 6 and the third choice was item number 2 (starting to count the list of items at 0).
There are many of these entries, so the function needs to calculate the votes for each item respectively and also display the items ranked by the votes and not as they are defined in the list.
For some reason, placeholders like [[choice_first#name]] are not substituted in the
javascript template. Therefore, the string is hard coded there. In case you change
the names in the field list, make sure to change these here as well. In all
other templates, the placeholders are used, so the terms update automatically.
This template contains some logic to handle the selections for each item. This is done with javascript. The real fields of this activity are hidden input fields. An event is attached to the submit buttons in the footer that takes the selected options on the page and puts the value into the hidden field.
Also, when a choice is set for one item, this choice is disabled in all other selections. This should avoid that a user can set several first or second picks. There can be one first choice of an item only.