Auto merge of #14086 - chajath:time-datetime-attribute, r=<try>

[WIP] Add DateTime string attribute to Time

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---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix part of #12967, content parsing will come as a separate PR.

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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/script/dom/htmltimeelement.rs

@@ -2,23 +2,27 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+use dom::bindings::codegen::Bindings::ElementBinding::ElementBinding::ElementMethods; 
 use dom::bindings::codegen::Bindings::HTMLTimeElementBinding;
+use dom::bindings::codegen::Bindings::HTMLTimeElementBinding::HTMLTimeElementMethods;
+use dom::bindings::inheritance::Castable;
 use dom::bindings::js::Root;
 use dom::bindings::str::DOMString;
 use dom::document::Document;
+use dom::element::Element;
 use dom::htmlelement::HTMLElement;
 use dom::node::Node;
 use html5ever_atoms::LocalName;
 
 #[dom_struct]
 pub struct HTMLTimeElement {
-    htmlelement: HTMLElement
+    htmlelement: HTMLElement,
 }
 
 impl HTMLTimeElement {
     fn new_inherited(local_name: LocalName, prefix: Option<DOMString>, document: &Document) -> HTMLTimeElement {
         HTMLTimeElement {
-            htmlelement: HTMLElement::new_inherited(local_name, prefix, document)
+            htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
         }
     }
 
@@ -31,3 +35,21 @@ impl HTMLTimeElement {
                            HTMLTimeElementBinding::Wrap)
     }
 }
+
+impl HTMLTimeElementMethods for HTMLTimeElement {
+    // https://html.spec.whatwg.org/multipage/#dom-time-datetime
+    fn DateTime(&self) -> DOMString {
+        let element = self.upcast::<Element>();
+        if element.has_attribute(&local_name!("datetime")) {
+            return element.get_string_attribute(&local_name!("datetime"))
+        } else {
+            match element.GetInnerHTML() {
+                Ok(x) => x,
+                _ => DOMString::new(),
+            }
+        }
+    }
+
+    // https://html.spec.whatwg.org/multipage/#dom-time-datetime
+    make_setter!(SetDateTime, "datetime");
+}

components/script/dom/webidls/HTMLTimeElement.webidl

@@ -4,5 +4,5 @@
 
 // https://html.spec.whatwg.org/multipage/#htmltimeelement
 interface HTMLTimeElement : HTMLElement {
-  //         attribute DOMString dateTime;
+  attribute DOMString dateTime;
 };

tests/wpt/web-platform-tests/html/semantics/text-level-semantics/the-time-element/001.html

@@ -47,21 +47,23 @@
 //dateTime
 test(function () {
   assert_equals( makeTime('2000-02-01T03:04:05Z','2001-02-01T03:04:05Z').dateTime, '2000-02-01T03:04:05Z' );
-}, 'the datetime attribute should be reflected by the .dateTime property');
+}, 'the datetime attribute should be reflected by the dateTime IDL property');
 test(function () {
   assert_equals( typeof makeTime().dateTime, 'string', 'typeof test' );
   assert_equals( makeTime().dateTime, '', 'value test' );
 }, 'the dateTime IDL property should default to an empty string');
 test(function () {
   assert_equals( makeTime(false,false,'2000-02-01T03:04:05Z').dateTime, '2000-02-01T03:04:05Z' );
-}, 'the dateTime property should be read/write');
+}, 'the dateTime IDL property should be read/write');
 test(function () {
   assert_equals( makeTime('go fish').dateTime, 'go fish' );
 }, 'the datetime attribute should be reflected by the .dateTime property even if it is invalid');
 test(function () {
-  assert_equals( makeTime(false,'2000-02-01T03:04:05Z').dateTime, '' );
-}, 'the datetime attribute should not reflect the textContent');
-
+  assert_equals( makeTime(false,'2000-02-01T03:04:05Z', '2000-02-01').dateTime, '2000-02-01' );
+}, 'the datetime content attribute should not reflect the textContent when datetime attribute is present.');
+test(function () {
+  assert_equals( makeTime(false,'2000-02-01T03:04:05Z').dateTime, '2000-02-01T03:04:05Z' );
+}, 'the datetime content attribute should reflect the textContent when datetime attribute is absent.');
     </script>
 
   </body>