Use case

Steps to follow

1. if(input.Invoice != "")
2. {
3. ext = input.Invoice.toList(".").get(input.Invoice.toList(".").size() - 1);
4. if(!allowed_list.contains(ext))
5. {
6.   alert "This file type is not accepted";
7.  
8. // Restricts the form from being submitted
9.   cancel submit;
10. }
11. }
    

See how it works

Points to note

• This tutorial demonstrates the use case with a File Upload field type. The same snippet would also work for the Audio and Video field types.
  
• Unlike the other file type fields, applying the input keyword on an Image field doesn’t directly return the file name.
  

1. info Input.Image;

1. src = input.Image.executeXPath("/img/@src").executeXpath("/src/text()");
2. //Fetches the value stored against the src attribute
3. ext = src.toList(".").get(src.toList(".").size() - 1);
4. // Fetches the extension of the file from the file path

Related links

• ToList built-in function
• Get built-in function
• If statement
• Cancel submit
• ExecuteXml