We've seen that it's possible to add a free-text filter on an event attribute in an event form.
It is also possible to filter based on a list of possible attribute values for one or more attributes on an event form.
In order to have a drop-down list on an attribute in the first place, you need to configure the attribute in the event to be associated with an enumeration.
Then, when you add that attribute to an event form, additional filtering options are available upon selecting the attribute and right-clicking in the filter configuration area of the form editor.
Notice the options to add an "Enumeration" or an "Enumeration Group" filter. More about the Enumeration Group filter later.
With an Enumeration filter, you can configure your form so that only certain attribute values may be selected by users capturing data with that particular form.
For example, you may want to create a form for downtime reason capturing, where the discipline (e.g. Mechanical, Electrical, Instrumentation) responsible for the downtime is selectable in a drop-down list for an attribute named "Discipline". At the same time though, you want to configure your form so that the users that have access to this form can only select the "Mechanical" discipline.
This may be done with an Enumeration Filter.
After selecting “Enumeration”, the filter may be configured in the third pane. Based on the enumeration that is linked to the attribute in the event attribute configuration, you will get a list of options that you can check/uncheck to indicate whether the option must be hidden or available for selection in the form.
You have the option to either "Include" the selected items in the drop-down list available to the form user on the front-end, or the "Exclude" the selected items.
If a prior selection was made before the filter was applied, or if the attribute value was automatically set from another source, but the value is not in the filtered list that you've now configured in the form editor, the form front-end will highlight this in red for the specific attribute value.
If a user attempts to use this form to modify the attribute value highlighted in red, s/he will only be able to change the value to one of the available values in the filter list.