ProcessMaker Forum | BPM Workflow Simplified

//change to the ID of the grid:
var gridId = "productsList";
//set to ID of the File field in grid:
var gridFileId = 'productFile';

var reFileInGrid = new RegExp("^\\["+gridId+"\\]\\[(\\d+)\\]\\["+gridFileId+"\\]$");
var formId = $("form").prop("id");

$("#"+formId).setOnchange( function(fieldId, filename, oldValue) {
  var aMatch = fieldId.match(reFileInGrid);
  
  //if the "productFile" field was changed in the "productsList" grid:
  if (aMatch) {
    var rowNo = aMatch[1];
    var basename = filename;
    
    if (filename.lastIndexOf(".") != -1) {       
      basename = filename.substring(0, filename.lastIndexOf("."));
    }
    
    //Search for duplicate filenames that have been uploaded in the same grid.
    //If a duplicate is found, then delete this file and display an alert message 
    //to the user saying that duplicate filenames are not allowed.
    var oGrid = $("#"+gridId);
    var nRows = oGrid.getNumberRows();
    
    
    for (var i = 1; i <= nRows; i++) {
      var fileFieldId = "form["+gridId+"]["+i+"]["+gridFileId+"]";
      var oFileButton = $("[id='"+fileFieldId+"']").parent().find("button");
      var filenameInRow = oFileButton.text();
     
      if (i != rowNo && filenameInRow != '' && filename == filenameInRow) {
        alert("The file '"+filename+"' has already been uploaded in row "+i+".\n"+
              "Duplicate files are not allowed.");
        
        //remove filename from File's button:
    	$("[id='"+"form"+fieldId+"']").parent().find("button").text("Allowed file extensions: *"); 
    	$("[id='"+"form"+fieldId+"']").val('');       //clear hidden file input field
    	$("[id='"+"form"+fieldId+"_label']").val(''); //clear filename in hidden text field
      }
    }
    
    //set the file's basename in the "productName" field for the same grid row:
    $("#productsList").setValue(basename, rowNo, 1);
    
  } 
});