View this page in the latest version of Appian. a!defaultValue Function Share Share via LinkedIn Reddit Email Copy Link Print On This Page How to Handle Null and Empty Values in Your Apps Learn how to use two Appian functions—a!defaultValue() and a!isNullOrEmpty—to prevent your app from throwing an error when it encounters null or empty values. Function a!defaultValue( value, default ) Returns a default value when the specified value is null or empty. When there are multiple default parameters, each parameter is evaluated in order and the first non-null and non-empty default will be returned. Null, "", and {} are all considered null or empty values. See also: if(), isnull() Parameters Keyword Type Description value Any Type Value to be returned if not null or empty. default Any Type Default value to return when value is null or empty. Returns Any Type Examples Basic 1 a!defaultValue(null, 1) Returns 1. 1 a!defaultValue(1, "default") Returns 1. Using null or empty values 1 a!defaultValue("", "default") Returns "default". 1 a!defaultValue(null, "") Returns "". 1 a!defaultValue({}, "default") Returns "default". An empty list is considered null or empty. Using multiple default parameters This function accepts multiple default parameters. Each parameter will be evaluated in order until the first non-null and non-empty default is returned. 1 a!defaultValue(null, "", {}) Returns {}. 1 a!defaultValue(null, "", 1, "", {}) Returns 1. Using lists 1 a!defaultValue({1, 9}, {2, 3, 4, 5}) Returns {1, 9}. A list of values is treated as a single value of type list. 1 a!defaultValue({null, null}, {3}) Returns {null, null}. A list of nulls is not considered null or empty. 1 a!defaultValue({"", "", ""}, {3}) Returns {"", "", ""}. A list of empty text is not considered null or empty. 1 a!defaultValue({{1,2,3}, {4,5}}, "default") Returns {1, 2, 3, 4, 5}. Lists of lists are flattened. 1 a!defaultValue(null, {2, {3, 4}, 5}) Returns {2, 3, 4, 5}. Lists of lists are flattened. Feature compatibility The table below lists this function's compatibility with various features in Appian. Feature Compatibility Note Portals Compatible Offline Mobile Compatible Sync-Time Custom Record Fields Compatible Can be used to create a custom record field that only evaluates at sync time. Real-Time Custom Record Fields Incompatible Custom record fields that evaluate in real time must be configured using one or more Custom Field functions. Process Reports Incompatible Cannot be used to configure a process report. Process Events Incompatible Cannot be used to configure a process event node, such as a start event or timer event. Feedback Was this page helpful? SHARE FEEDBACK Loading...
