Certain types of variables can create blank values when an end user does not input information.
Blank values are created when:
- an input was set as optional and then skipped by the end user, or
- the end user followed a different path through the module and did not reach the node and its variable.
You can work with blank values using the Rule Builder.
Number, Date, Text and Email Address variables can create blank values.
Build conditions with blank values
Using the Rule Builder, you can build conditions with blank values (variable = Blank or variable ≠ Blank). By leaving the value field blank you can build a condition based on whether or not an input was provided or an associated value exists.
When building conditions, you cannot always predict whether or not a variable will create a blank value. If you reference a variable in the value field of your condition, and this variable has a blank value, the following logic will be applied:
- If a condition is configured as
[variable] = [value]and the value is blank, the condition will return as false.
- If a condition is configured as
[variable] ≠ [value]and the value is blank, the condition will return as true.
- Referencing a blank text value will not return any text.
- A blank number variable creates the value 0. A condition configured as, e.g.,
[number variable] = Blankis synonymous with[number variable] = 0. Referencing a blank number variable will return the value 0. - A blank date variable creates the value 01-01-2000. Referencing a blank date variable will return the value 01-01-2000.
Note that when calculating with numbers or dates, a blank number variable also creates the value 0 and a blank date variable also creates the value 01-01-2000.
Some built-in values can return as blank, e.g., a name or email address when a module is public.
Related topics
- Find out what operators and values are available based on the type of variable in this article.
- Blank or empty values can be used to initialize a node and then populate its content through updating.