Fix detached callback and add isAttached to SkyElements.

There was a typo in the name of the detached callback which is now fixed,
and also allow querying if an element is attached.

R=rafaelw@chromium.org

Review URL: https://codereview.chromium.org/806133003

framework/sky-element/sky-element.sky

@@ -36,7 +36,7 @@ class SkyElement extends HTMLElement {
     // override
   }
 
-  dettached() {
+  detached() {
     // override
   }
 
@@ -49,6 +49,7 @@ class SkyElement extends HTMLElement {
   }
 
   createdCallback() {
+    this.isAttached = false;
     this.created();
   }
 
@@ -63,10 +64,12 @@ class SkyElement extends HTMLElement {
       }
     }
     this.attached();
+    this.isAttached = true;
   }
 
-  dettachedCallback() {
-    this.dettached();
+  detachedCallback() {
+    this.detached();
+    this.isAttached = false;
   }
 
   attributeChangedCallback(attrName, oldValue, newValue) {

tests/framework/templates-expected.txt

@@ -1,8 +1,9 @@
-Running 4 tests
+Running 5 tests
 ok 1 SkyElement templates should stamp when the element is inserted
-ok 2 SkyElement templates should connect data binding
-ok 3 SkyElement templates should connect event handlers
-ok 4 SkyElement templates should call shadowRootReady after creating the template instance
-4 tests
-4 pass
+ok 2 SkyElement templates should update isAttached when inserting
+ok 3 SkyElement templates should connect data binding
+ok 4 SkyElement templates should connect event handlers
+ok 5 SkyElement templates should call shadowRootReady after creating the template instance
+5 tests
+5 pass
 0 fail

tests/framework/templates.sky

@@ -24,6 +24,14 @@ describe("SkyElement templates", function() {
     assert.ok(element.shadowRoot.getElementById("inside"));
   });
 
+  it("should update isAttached when inserting", function() {
+    assert.isFalse(element.isAttached);
+    sandbox.appendChild(element);
+    assert.isTrue(element.isAttached);
+    element.remove();
+    assert.isFalse(element.isAttached);
+  });
+
   it("should connect data binding", function(done) {
     sandbox.appendChild(element);
     var inside = element.shadowRoot.getElementById("inside");