KB-2003 Quick App "Trends" tab fails to load when user field added due to invalid value for "links"

Symptoms

After creating a Quick App (New Application --> Create Using Application Builder (Full)), specifying a user field for the form, and submitting a data entry through the Quick App, the following error is encountered:

"Expression evaluation error at function a!gridField [line XXX]: A grid component [label=“null”] has an invalid value for “columns”. A grid column [label=“<USER_FIELD>”] has encountered an error. Expression evaluation error at function a!linkField [line XXX]: An AnyLinkField component [label=“”] has an invalid value for “links”. The array of links cannot have null items."

Cause

The generated Quick App interface for the "Trends" tab has a format username expression rule!IST_FormatName(fv!row.<userfield>() that is wrapping the username parameter of the expression rule!IST_UserRecordLink() rather than the label parameter. This issue has been reported to the Appian Product Team. The reference number for this issue is AN-140630.

Workaround

Navigate to the interface for the "Trends" tab *_All<Record_Singular>: to find the interface, open the site object for the Quick App, click the <Record_Singular> link within the Content column under the Pages section, and then open the Interface object.
Replace the code for the user grid column with the following code:

Note: The best way to find the section of code that must be replaced is to search for UserRecordLink in the SAIL expression mode:

a!gridColumn(
 label: "<User_Field>",
 sortField: "<userfield>",
 value: a!linkField(
 links: {if(isnull(fv!row.<userfield>),{},
 rule!XXXXX_UserRecordLink(
 fv!row.<userfield>,
 XXXXX_FormatName(fv!row.<userfield>)
 )
 )
 }
 )
 )

Affected Versions

This article applies to Appian 19.2 and 19.3.

Last Reviewed: September 2019