How to validate CSV file whether it is in correct format or not ?

Question

Hi Everyone, 
 I want implement a validation on file upload field, whenever user uploads a CSV file system will validate and check whether the CSV file uploaded is in correct format or not ? 
 if file is not in correct format system will give the error "File is not in correct format"

aliakbar2000 · Answer

Hi Sachin, You can add the following code in validations parameter of a!fileUploadfield() that will check where the file is in .csv format code: 
 validations: { a!localVariables( local!invalidExtensions: difference( upper(fv!files.extension), { "CSV"} ), 
 if( length(local!invalidExtensions) > 0, "Please upload supported file formats: CSV", "" ) ) }

Konduru Chaitanya · Answer

Hello sachink2402 
 What do you mean format? Do you mean the file extension type? If so below the code that would help. 
 {
 a!fileUploadField(
 label: "File Upload",
 labelPosition: "ABOVE",
 target: cons!FOLDER_CONSTANT,
 saveInto: ri!file,
 value: ri!file,
 validations: a!localVariables(
 local!invalidExtensions: difference(upper(fv!files.extension), "CSV"),
 if(
 length(local!invalidExtensions) > 0,
 "Attachments must be pdf files. Remove: " & index(
 fv!files,
 "name",
 wherecontains(
 local!invalidExtensions,
 upper(fv!files.extension)
 ),
 {}
 ),
 ""
 )
 )
 )
} 
 Validation from documentation. Please refer THIS for more information 
 docs.appian.com/.../File_Upload_Component.html