a!imageField(
  label: "test",
  images: a!applyComponents(
    function: rule!Testdocdonload(
      uploadedDocuments: ri!uploadedDocuments,
      index: _
    ),
    array: 1 + enumerate(
      count(
        ri!uploadedDocuments
      )
    )
  )
)

===================================================================
Supporting Rule
===================================================================
load(
  local!extension: document(
    ri!uploadedDocuments[ri!index],
    "extension"
  ),
  local!index: whereContains(
    local!extension, 
    cons!ExtensionsArray   /* pdf;doc;xls;txt	 */
  ),
  local!image: cons!DocumentsImagesArray[local!index],  /* document images */
  a!documentImage(
    document: local!image,
    altText: "Some text",
    caption: "Some Text",
    link: a!documentDownloadLink(
      label: document(
        ri!uploadedDocuments[ri!index],
        "name"
      ),
      document: todocument(
        ri!uploadedDocuments[ri!index]
      )
    )
  )
)