Fix issue processwire/processwire-issues#202 where the leave confirm box was appearing when it shouldn't, after saving after a file had been uploaded. Also added drag/drop protection so that if you accidentially drag/drop a file outside of the specified dropzone, it gets ignored, rather than loading the file in the browser.

Author: ryancramerdesign

Diff for: modules/Inputfield/InputfieldFile/InputfieldFile.js

@@ -405,7 +405,7 @@ $(document).ready(function() {
 			}, false);
 			dropArea.addEventListener("dragenter", function() { 
 				$(this).addClass('ui-state-hover'); 
-				$(this).closest('.Inputfield').addClass('pw-drag-in-file InputfieldStateConfirmLeave');
+				$(this).closest('.Inputfield').addClass('pw-drag-in-file');
 			}, false);
 
 			dropArea.addEventListener("dragover", function (evt) {
@@ -419,7 +419,7 @@ $(document).ready(function() {
 
 			dropArea.addEventListener("drop", function (evt) {
 				traverseFiles(evt.dataTransfer.files);
-				$(this).removeClass("ui-state-hover").closest('.Inputfield').removeClass('pw-drag-in-file InputfieldStateConfirmLeave');
+				$(this).removeClass("ui-state-hover").closest('.Inputfield').removeClass('pw-drag-in-file');
 				evt.preventDefault();
 				evt.stopPropagation();
 			}, false);		

Diff for: modules/Inputfield/InputfieldFile/InputfieldFile.min.js

@@ -1176,7 +1176,7 @@ function InputfieldImage($) {
 				function dragStart() {
 					if($inputfield.hasClass('pw-drag-in-file')) return;
 					$el.addClass('ui-state-hover');
-					$inputfield.addClass('pw-drag-in-file InputfieldStateConfirmLeave');
+					$inputfield.addClass('pw-drag-in-file');
 				}
 
 				function dragStop() {

Diff for: modules/Inputfield/InputfieldImage/InputfieldImage.js

@@ -900,7 +900,6 @@ function InputfieldColumnWidths($target) {
  */
 function InputfieldFormBeforeUnloadEvent(e) {
 	var $changes = $(".InputfieldFormConfirm:not(.InputfieldFormSubmitted) .InputfieldStateChanged");
-	if($changes.length == 0) $changes = $('.InputfieldStateConfirmLeave');
 	if($changes.length == 0) return;
 	var msg = $('.InputfieldFormConfirm:eq(0)').attr('data-confirm') + "\n";
 	$changes.each(function() {
@@ -1217,7 +1216,21 @@ function InputfieldIntentions() {
 			// allow submissions again once they are out of the field
 			$form.removeClass('nosubmit');
 		}); 
-	}); 
+	});
+
+	// prevent dragged in files from loading in the browser (does not interfere with other drag/drop handlers)
+	if($("input[type=file]").length) {
+		$(document).on({
+			dragover: function() {
+				if($(this).is("input[type=file]")) return;
+				return false;
+			},
+			drop: function() {
+				if($(this).is("input[type=file]")) return;
+				return false;
+			}
+		});
+	}
 }
 
 /***********************************************************************************/