refactor(i18n): misc

modules/@angular/compiler/src/i18n/i18n_html_parser.ts

@@ -20,60 +20,7 @@ let _PLACEHOLDER_EXPANDED_REGEXP = /<ph(\s)+name=("(\w)+")><\/ph>/gi;
  *
  * Algorithm:
  *
- * To understand the algorithm, you need to know how partitioning works.
+ * See `message_extractor.ts` for details on the partitioning algorithm.
- * Partitioning is required as we can use two i18n comments to group node siblings together.
- * That is why we cannot just use nodes.
- *
- * Partitioning transforms an array of HtmlAst into an array of Part.
- * A part can optionally contain a root element or a root text node. And it can also contain
- * children.
- * A part can contain i18n property, in which case it needs to be translated.
- *
- * Example:
- *
- * The following array of nodes will be split into four parts:
- *
- * ```
- * <a>A</a>
- * <b i18n>B</b>
- * <!-- i18n -->
- * <c>C</c>
- * D
- * <!-- /i18n -->
- * E
- * ```
- *
- * Part 1 containing the a tag. It should not be translated.
- * Part 2 containing the b tag. It should be translated.
- * Part 3 containing the c tag and the D text node. It should be translated.
- * Part 4 containing the E text node. It should not be translated.
- *
- *
- * It is also important to understand how we stringify nodes to create a message.
- *
- * We walk the tree and replace every element node with a placeholder. We also replace
- * all expressions in interpolation with placeholders. We also insert a placeholder element
- * to wrap a text node containing interpolation.
- *
- * Example:
- *
- * The following tree:
- *
- * ```
- * <a>A{{I}}</a><b>B</b>
- * ```
- *
- * will be stringified into:
- * ```
- * <ph name="e0"><ph name="t1">A<ph name="0"/></ph></ph><ph name="e2">B</ph>
- * ```
- *
- * This is what the algorithm does:
- *
- * 1. Use the provided html parser to get the html AST of the template.
- * 2. Partition the root nodes, and process each part separately.
- * 3. If a part does not have the i18n attribute, recurse to process children and attributes.
- * 4. If a part has the i18n attribute, merge the translated i18n part with the original tree.
  *
  * This is how the merging works:
  *

modules/@angular/compiler/src/i18n/message_extractor.ts

@@ -147,6 +147,7 @@ export class MessageExtractor {
         isPresent(this._implicitAttrs[p.name]) ? this._implicitAttrs[p.name] : [];
     let explicitAttrs: string[] = [];
 
+    // `i18n-` prefixed attributes should be translated
     p.attrs.filter(attr => attr.name.startsWith(I18N_ATTR_PREFIX)).forEach(attr => {
       try {
         explicitAttrs.push(attr.name.substring(I18N_ATTR_PREFIX.length));
@@ -161,6 +162,7 @@ export class MessageExtractor {
       }
     });
 
+    // implicit attributes should also be translated
     p.attrs.filter(attr => !attr.name.startsWith(I18N_ATTR_PREFIX))
         .filter(attr => explicitAttrs.indexOf(attr.name) == -1)
         .filter(attr => transAttrs.indexOf(attr.name) > -1)

modules/@angular/compiler/src/i18n/shared.ts

@@ -77,7 +77,7 @@ function _isOpeningComment(n: HtmlAst): boolean {
 }
 
 function _isClosingComment(n: HtmlAst): boolean {
-  return n instanceof HtmlCommentAst && isPresent(n.value) && n.value == '/i18n';
+  return n instanceof HtmlCommentAst && isPresent(n.value) && n.value === '/i18n';
 }
 
 function _findI18nAttr(p: HtmlElementAst): HtmlAttrAst {