[JENKINS-19835] added page-leave confirmation on the configuration page

core/src/main/resources/hudson/model/Job/configure.jelly

@@ -63,11 +63,12 @@ THE SOFTWARE.
         <j:if test="${h.hasPermission(it,it.CONFIGURE)}">
           <f:bottomButtonBar>
             <!--<input type="button" name="StructureTest" value="Test" onclick="buildFormTree(this.form)" />-->
-            <f:submit value="${%Save}" />
+            <f:submit value="${%Save}"/>
             <f:apply />
           </f:bottomButtonBar>
         </j:if>
       </f:form>
+      <st:adjunct includes="lib.form.confirm" />
     </l:main-panel>
   </l:layout>
 </j:jelly>

core/src/main/resources/lib/form/apply.jelly

@@ -35,5 +35,5 @@ THE SOFTWARE.
   </s:documentation>
   <st:adjunct includes="lib.form.apply.apply"/>
   <input type="hidden" name="core:apply" value="" />
-  <input type="button" value="${%Apply}" class="apply-button applyButton" /><!-- applyButton is legacy -->
+  <input type="button" value="${%Apply}" class="apply-button applyButton" name="Apply"/><!-- applyButton is legacy -->
 </j:jelly>

core/src/main/resources/lib/form/confirm.js

@@ -0,0 +1,63 @@
+var errorMessage = "Leave without saving?";
+var needToConfirm = false;
+
+window.onbeforeunload = confirmExit;
+Event.observe(window, 'load', initConfirm);
+
+function initConfirm() {
+  var configForm = document.getElementsByName("config")[0];
+
+  var buttons = configForm.getElementsByTagName("button");
+  var name;
+  for ( var i = 0; i < buttons.length; i++) {
+    name = buttons[i].parentNode.parentNode.getAttribute('name');
+    if (name == "Submit") {
+      addEventToElement(buttons[i], 'click', function() {
+        needToConfirm = false;
+      });
+    } else if (name == "Apply") {
+    } else {
+      addEventToElement(buttons[i], 'click', confirm);
+    }
+  }
+
+  var inputs = configForm.getElementsByTagName("input");
+  for ( var i = 0; i < inputs.length; i++) {
+    addEventToElement(inputs[i], 'change', confirm);
+    if (inputs[i].type == 'checkbox' || inputs[i].type == 'radio') {
+      addEventToElement(inputs[i], 'click', confirm);
+    } else {
+      addEventToElement(inputs[i], 'keydown', confirm);
+    }
+  }
+
+  inputs = configForm.getElementsByTagName("select");
+  for ( var i = 0; i < inputs.length; i++) {
+    addEventToElement(inputs[i], 'keydown', confirm);
+    addEventToElement(inputs[i], 'click', confirm);
+  }
+
+  inputs = configForm.getElementsByTagName("textarea");
+  for ( var i = 0; i < inputs.length; i++) {
+    addEventToElement(inputs[i], 'keydown', confirm);
+  }
+}
+
+function confirm() {
+  needToConfirm = true;
+}
+
+function addEventToElement(obj, evType, fn) {
+  if (obj.addEventListener) {
+    obj.addEventListener(evType, fn, false);
+    return true;
+  } else if (obj.attachEvent) {
+    return obj.attachEvent("on" + evType, fn);
+  }
+}
+
+function confirmExit() {
+  if (needToConfirm) {
+    return errorMessage;
+  }
+}