CategoryDropdownReference handler is used to generate dependencies between category dropdowns. With this handler, it is possible to state that another dropdown gets its possible values according to this handler's selected dropdown value.

Editing a data card that holds multiple category dropdowns (each "Category X" attribute). The screenshot is taken with Firefox. Internet Explorer would leave the "Category 4" dropdown white, instead of grey:

The image above shows an example of a dependency category. 

• The value of the "Category 1" limits down the possible values that the "Category 2" can have, and the "Category 2" limits down the possible values of the "Category 3", and so on. 
• In this example, the root of the dropdown category ("Category 1") is configured to refer to all the data cards of a certain template. 
  • The next level category ("Category 2") is also configured to refer to all the data cards of a possibly different template (the template may be different that the referred template of the "Category 1"). 
  • But as the "Category 2" is the child of the "Category 1", there has to be a configuration that links the data cards of the referred template of the "Category 2" to the data card chosen from the category dropdown of the "Category 1". 
  • This means that the eligible data cards for the "Category 2" must refer to the already selected data card in the "Category 1". 
• In the image above, the "Application Services" data card refers to the "Servers and Storage" data card.

To enable "Reserve Ticket"-button function, please see Handler - TicketReservation 

Table 1. Attribute Settings

Table 2. Required Attribute Metadata

Table 3. Optional Attribute Metadata

Configuration Examples

An example setup of a dependency category with one category template:

1. Create a category template that has a parent data card referrer attribute (an attribute that refers to this same template just created) and a name field.
2. Create a template that has two (or any number of your choice) attributes with CategoryDropdownReference handler. Set this template to refer to the category template.
3. Give all the templates and attributes a unique code. (Attribute codes only need to be unique within one template.)
4. Configure the first attribute with the handler (the dependency category root). In metadata, set the "Category template" to have the code of the category template as its value. Set the "Attribute for parent category in category template" to have the code of the parent data card referrer attribute as its value. Set no "Attribute for parent category" configuration, because this is the dependency category root configuration.
5. Configure the other handler attribute: set the "Category template" and the "Attribute for parent category in category template" to be the same as in the first configuration explained above. Set the "Attribute for parent category" to have the value of the previous handler attribute.
6. Create data cards of the category template: create one or more data cards that have no parent, and the create one or more data cards that have a parent.
7. The dependency category is ready to be used.

Another example setup of a dependency category, but with multiple category templates:

1. Follow the above example to set up the basic configuration.
2. Create another category template with another parent data card referrer attribute, which refers to both this new category template and the category template previously created. This way the data cards of this template may belong to the category tree made up of the previously created template's data cards (a parent-child relation is created, which is a prerequisite for mapping data cards to a dependency category).
3. Create a new CategoryDropdownReference handler attribute to accompany the other previously created ones. Configure them to point to their parents (see "Attribute for parent category"). Set the "Category template" and the "Attribute for parent category in category template" to point to the new category template. Set this attribute to refer to the new category template just created.
4. We now have two category templates, one host template (the template holding these CategoryDropdownReference handlers) and three attributes with that handler. The first category dropdown lists category root data cards of the first category template, the second category dropdown lists the data cards that have the selected category data card as their parent, and the last category dropdown lists the data cards of the second category template that have the another selected category data card as their parent.

It is also possible to set the highest category dropdown to depend on a normal reference. Here is a use case for this kind of a situation: my company has a hierarchical organization. While editing a data card, I wish to enter my unit in the organization by selecting it from the dependency category.

Continent, Country, Strategic Business Unit and Team are disabled, since the Company has not yet been selected:

In this configuration, Continent's "Attribute for parent category" is the code of the Company attribute, Country's "Attribute for parent category" is the code of the Continent attribute, and so on.

Select a one of the available options in Company to enable selecting a Continent.

The Continent selection is now enabled, since Asia, Europe and America refer to My company.
 

Further, it is now possible to select the Country, the Strategic Business Unit, as well as the Team.

Notice how Europe, Asia and America refer to My company. This enables the highest category dropdown to depend on a normal reference.

Table 4. Glossary