Page Comparison

Example

Code

{
      "name" : "specimen.extensionDetail.attrsMap.core_size_mm",
      "caption" : "Core Size (mm)",
      "type" : "text",
      "showInOverviewIfshowIf" : "!!specimen.extensionDetail.attrsMap.core_size_mm",
      "showInOverviewIf" : "useShowIf"
      "optional" : true,
}

Displays the "Core Size (mm)" field in the edit and overview page only if it has a value.

Explaination: Uses the double negation (!!) to check whether core_size_mm has a true value.
If core_size_mm is empty, null, or undefined, this condition will evaluate to false, preventing the field from displaying in edit and overview page.