1. Go to Setup > Developer Space > Client Script. Click +New Script . Specify the details to create a script and click Next.

1. // Check if the current blueprint transition being triggered is "Deal Accepted" or "Deal Rejected"
2. if (transition.name == "Deal Accepted" || transition.name == "Deal Rejected") {
3. 
   
4.     // Get the value of the Test field (file upload field)
5.     var objectArray = ZDK.Page.getField('Test').getValue();
6. 
   
7.     // Log the field value to console for debugging purposes
8.     log(objectArray);
9. 
   
10.     // Check if the field is empty - covers empty string, null, and empty array cases
11.     if ((objectArray == '' || objectArray == null || objectArray == '[]')) {
12. 
    
13.         // Show an error message to the user if no file is attached
14.         ZDK.Client.showMessage("Upload a **valid Proposal Document PDF** to proceed", error)
15. 
    
16.         // Stop/block the blueprint transition since validation failed
17.         return false;
18. 
    
19.     }
20.     else {
21. 
    
22.         // If a file is attached, get the name of the first uploaded file
23.         var fileName = objectArray[0].File_Name;
24.         log(fileName);
25. 
    
26.         // Extract the file extension from the file name and convert it to lowercase
27.         var extension = fileName.substring(fileName.lastIndexOf('.') + 1).toLowerCase();
28.       
29.  // Check if the uploaded file's extension is not "pdf"
30.         if (extension != "pdf") {
31. 
    
32.             // Show an error message asking the user to upload a valid PDF file
33.             ZDK.Client.showMessage("The Proposal Document field accepts **only PDF files**. Please select a **.pdf file** and try again.", error);
34. 
    
35.             // Stop/block the blueprint transition since the file is not a PDF
36.             return false;
37.         }
38.     }
39. }

This script runs before the "Deal Accepted" or "Deal Rejected" blueprint transition. It checks whether the Proposal Document field has a file attached. If the field is empty, it shows an error and blocks the transition. If a file is attached, it checks the file's extension. If the extension isn't "pdf", it shows an error and blocks the transition; otherwise, the transition proceeds normally.

Note:

The value of a File Upload field is an array of objects, even when only a single file is uploaded. Therefore, access the required file object (for example, objectArray[0]) before retrieving its properties, such as File_Name

1. Here is how the Client Script works when no file is uploaded to the Proposal Document field.
   

1. Here is how the Client Script works when a GIF file is uploaded to the Proposal Document field.
   

1. If a valid PDF file is uploaded, the transition goes through smoothly without any issues.
   

3. Supported ZDKs

1. How to validate a file's extension and stop a Blueprint transition based on it.
2. How to check whether a file has been uploaded using Client Script.
3. ZDKs that can be used for File Upload and Image Upload fields.

5. Related Links  

• Client Script - An Overview

• Client Script - Best Practices

• Client Script - FAQs

• Empty and Update Fields When Cloning Deals