You are currently reviewing an older revision of this page.

DRAFT KB-XXXX 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

  1. 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.
  2. Replace the code for the user grid column with the following code to remediate the issue, as well as perform a null check in case the user field is not set to required. The easiest 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