Validate uploded document size getting error message saying that Invalid function fileUploadField_17r1

Question

We are on 17.1 version of Appian, I have a requirement to validate the uploaded document size 
 I have a requirement to validate the uploaded document size. Once the user has uploaded the file needs to be validated before submitting the form. so here I can not use document function. 
 tried several approaches like 
 a!fileupload( 
 value:ri!document, 
 target:"ABC LOCATION" 
 ).uploadedDocumentSize 
 the above approach is working in expression rules but at run time it is giving me an error saying that text can not convert to Layout. 
 Approach 2 
 a!fileUploadField_17r1( value: ri!document ).uploadedDocumentSize 
 
 Above approach is giving error message saying that Invalid function fileUploadField_17r1

chandolum · Answer

Thank you all for your response, 
 the above-attached code snippet solved my problem 
 root cause: In 17.1 version, file upload component is having a different set of attributes in design view and in the live view (execution time)

Fullscreen 
 uploadedFileSizeValidation.txt 
 Download 
 
 if(
 or(
 rule!APN_isBlank(
 ri!document
 ),
 tointeger(
 ri!document
 ) <= 0
 ),
 {
 fullName: "",
 name: "",
 ext: "",
 size: ""
 },
 with(
 local!value: a!fileUploadField(
 value: ri!document
 ),
 if(
 rule!APN_isBlank(
 property(
 local!value,
 "uploadedDocumentName",
 null()
 )
 ),
 /* get properties as rendered in 17.1+ process forms */
 if(
 rule!APN_isBlank(
 property(
 property(
 local!value,
 "contents",
 null()
 ),
 "name",
 null()
 )
 ),
 {
 fullName: "",
 name: "",
 ext: "",
 size: ""
 },
 {
 fullName: local!value.contents.name & "." & local!value.contents.extension,
 name: local!value.contents.name,
 ext: local!value.contents.extension,
 size: local!value.contents.size
 }
 ),
 /* for old style form rendering (pre-17.1, or in 17.1 interface designer) */
 with(
 local!fullName: local!value.uploadedDocumentName,
 local!parts: split(
 local!fullName,
 "."
 ),
 local!extension: if(
 length(
 local!parts
 ) > 1,
 index(
 local!parts,
 length(
 local!parts
 ),
 ""
 ),
 ""
 ),
 local!name: if(
 length(
 local!parts
 ) > 1,
 joinarray(
 rdrop(
 local!parts,
 1
 ),
 "."
 ),
 index(
 local!parts,
 1,
 ""
 )
 ),
 {
 fullName: local!fullName,
 name: local!name,
 ext: local!extension,
 size: local!value.uploadedDocumentSize
 }
 )
 )
 )
)