From ff1cd4267c49187c9742297641070e3cadd8e9ca Mon Sep 17 00:00:00 2001
From: vsavkin <avix1000@gmail.com>
Date: Tue, 12 Apr 2016 11:46:28 -0700
Subject: [PATCH 1/5] feat(html_lexer): support special forms used by i18n {
 exp, plural, =0 {} }

---
 modules/angular2/src/compiler/html_lexer.ts   | 131 +++++++++++++++++-
 .../angular2/test/compiler/html_lexer_spec.ts |  82 ++++++++++-
 2 files changed, 202 insertions(+), 11 deletions(-)

diff --git a/modules/angular2/src/compiler/html_lexer.ts b/modules/angular2/src/compiler/html_lexer.ts
index d3a90d74aae4..76f48683d9ac 100644
--- a/modules/angular2/src/compiler/html_lexer.ts
+++ b/modules/angular2/src/compiler/html_lexer.ts
@@ -25,6 +25,11 @@ export enum HtmlTokenType {
   ATTR_NAME,
   ATTR_VALUE,
   DOC_TYPE,
+  EXPANSION_FORM_START,
+  EXPANSION_CASE_VALUE,
+  EXPANSION_CASE_EXP_START,
+  EXPANSION_CASE_EXP_END,
+  EXPANSION_FORM_END,
   EOF
 }
 
@@ -43,8 +48,10 @@ export class HtmlTokenizeResult {
   constructor(public tokens: HtmlToken[], public errors: HtmlTokenError[]) {}
 }
 
-export function tokenizeHtml(sourceContent: string, sourceUrl: string): HtmlTokenizeResult {
-  return new _HtmlTokenizer(new ParseSourceFile(sourceContent, sourceUrl)).tokenize();
+export function tokenizeHtml(sourceContent: string, sourceUrl: string,
+                             tokenizeExpansionForms: boolean = false): HtmlTokenizeResult {
+  return new _HtmlTokenizer(new ParseSourceFile(sourceContent, sourceUrl), tokenizeExpansionForms)
+      .tokenize();
 }
 
 const $EOF = 0;
@@ -75,6 +82,9 @@ const $GT = 62;
 const $QUESTION = 63;
 const $LBRACKET = 91;
 const $RBRACKET = 93;
+const $LBRACE = 123;
+const $RBRACE = 125;
+const $COMMA = 44;
 const $A = 65;
 const $F = 70;
 const $X = 88;
@@ -108,16 +118,20 @@ class _HtmlTokenizer {
   private length: number;
   // Note: this is always lowercase!
   private peek: number = -1;
+  private nextPeek: number = -1;
   private index: number = -1;
   private line: number = 0;
   private column: number = -1;
   private currentTokenStart: ParseLocation;
   private currentTokenType: HtmlTokenType;
 
+  private inExpansionCase: boolean = false;
+  private inExpansionForm: boolean = false;
+
   tokens: HtmlToken[] = [];
   errors: HtmlTokenError[] = [];
 
-  constructor(private file: ParseSourceFile) {
+  constructor(private file: ParseSourceFile, private tokenizeExpansionForms: boolean) {
     this.input = file.content;
     this.length = file.content.length;
     this._advance();
@@ -149,6 +163,18 @@ class _HtmlTokenizer {
           } else {
             this._consumeTagOpen(start);
           }
+        } else if (isSpecialFormStart(this.peek, this.nextPeek) && this.tokenizeExpansionForms) {
+          this._consumeExpansionFormStart();
+
+        } else if (this.peek === $EQ && this.tokenizeExpansionForms) {
+          this._consumeExpansionCaseStart();
+
+        } else if (this.peek === $RBRACE && this.inExpansionCase && this.tokenizeExpansionForms) {
+          this._consumeExpansionCaseEnd();
+
+        } else if (this.peek === $RBRACE && !this.inExpansionCase && this.tokenizeExpansionForms) {
+          this._consumeExpansionFormEnd();
+
         } else {
           this._consumeText();
         }
@@ -218,6 +244,8 @@ class _HtmlTokenizer {
     }
     this.index++;
     this.peek = this.index >= this.length ? $EOF : StringWrapper.charCodeAt(this.input, this.index);
+    this.nextPeek =
+        this.index + 1 >= this.length ? $EOF : StringWrapper.charCodeAt(this.input, this.index + 1);
   }
 
   private _attemptCharCode(charCode: number): boolean {
@@ -506,20 +534,109 @@ class _HtmlTokenizer {
     this._endToken(prefixAndName);
   }
 
+  private _consumeExpansionFormStart() {
+    this._beginToken(HtmlTokenType.EXPANSION_FORM_START, this._getLocation());
+    this._requireCharCode($LBRACE);
+    this._endToken([]);
+
+    this._beginToken(HtmlTokenType.RAW_TEXT, this._getLocation());
+    let condition = this._readUntil($COMMA);
+    this._endToken([condition], this._getLocation());
+    this._requireCharCode($COMMA);
+    this._attemptCharCodeUntilFn(isNotWhitespace);
+
+    this._beginToken(HtmlTokenType.RAW_TEXT, this._getLocation());
+    let type = this._readUntil($COMMA);
+    this._endToken([type], this._getLocation());
+    this._requireCharCode($COMMA);
+    this._attemptCharCodeUntilFn(isNotWhitespace);
+
+    this.inExpansionForm = true;
+  }
+
+  private _consumeExpansionCaseStart() {
+    this._requireCharCode($EQ);
+
+    this._beginToken(HtmlTokenType.EXPANSION_CASE_VALUE, this._getLocation());
+    let value = this._readUntil($LBRACE).trim();
+    this._endToken([value], this._getLocation());
+    this._attemptCharCodeUntilFn(isNotWhitespace);
+
+    this._beginToken(HtmlTokenType.EXPANSION_CASE_EXP_START, this._getLocation());
+    this._requireCharCode($LBRACE);
+    this._endToken([], this._getLocation());
+    this._attemptCharCodeUntilFn(isNotWhitespace);
+
+    this.inExpansionCase = true;
+  }
+
+  private _consumeExpansionCaseEnd() {
+    this._beginToken(HtmlTokenType.EXPANSION_CASE_EXP_END, this._getLocation());
+    this._requireCharCode($RBRACE);
+    this._endToken([], this._getLocation());
+    this._attemptCharCodeUntilFn(isNotWhitespace);
+
+    this.inExpansionCase = false;
+  }
+
+  private _consumeExpansionFormEnd() {
+    this._beginToken(HtmlTokenType.EXPANSION_FORM_END, this._getLocation());
+    this._requireCharCode($RBRACE);
+    this._endToken([]);
+
+    this.inExpansionForm = false;
+  }
+
   private _consumeText() {
     var start = this._getLocation();
     this._beginToken(HtmlTokenType.TEXT, start);
-    var parts = [this._readChar(true)];
-    while (!isTextEnd(this.peek)) {
+
+    var parts = [];
+    let interpolation = false;
+
+    if (this.peek === $LBRACE && this.nextPeek === $LBRACE) {
+      parts.push(this._readChar(true));
+      parts.push(this._readChar(true));
+      interpolation = true;
+    } else {
       parts.push(this._readChar(true));
     }
+
+    while (!this.isTextEnd(interpolation)) {
+      if (this.peek === $LBRACE && this.nextPeek === $LBRACE) {
+        parts.push(this._readChar(true));
+        parts.push(this._readChar(true));
+        interpolation = true;
+      } else if (this.peek === $RBRACE && this.nextPeek === $RBRACE && interpolation) {
+        parts.push(this._readChar(true));
+        parts.push(this._readChar(true));
+        interpolation = false;
+      } else {
+        parts.push(this._readChar(true));
+      }
+    }
     this._endToken([this._processCarriageReturns(parts.join(''))]);
   }
 
+  private isTextEnd(interpolation: boolean): boolean {
+    if (this.peek === $LT || this.peek === $EOF) return true;
+    if (this.tokenizeExpansionForms) {
+      if (isSpecialFormStart(this.peek, this.nextPeek)) return true;
+      if (this.peek === $RBRACE && !interpolation && this.inExpansionForm) return true;
+    }
+    return false;
+  }
+
   private _savePosition(): number[] {
     return [this.peek, this.index, this.column, this.line, this.tokens.length];
   }
 
+  private _readUntil(char: number): string {
+    let start = this.index;
+    this._attemptUntilChar(char);
+    return this.input.substring(start, this.index);
+  }
+
   private _restorePosition(position: number[]): void {
     this.peek = position[0];
     this.index = position[1];
@@ -558,8 +675,8 @@ function isNamedEntityEnd(code: number): boolean {
   return code == $SEMICOLON || code == $EOF || !isAsciiLetter(code);
 }
 
-function isTextEnd(code: number): boolean {
-  return code === $LT || code === $EOF;
+function isSpecialFormStart(peek: number, nextPeek: number): boolean {
+  return peek === $LBRACE && nextPeek != $LBRACE;
 }
 
 function isAsciiLetter(code: number): boolean {
diff --git a/modules/angular2/test/compiler/html_lexer_spec.ts b/modules/angular2/test/compiler/html_lexer_spec.ts
index a4c32142a871..aef9b096587f 100644
--- a/modules/angular2/test/compiler/html_lexer_spec.ts
+++ b/modules/angular2/test/compiler/html_lexer_spec.ts
@@ -576,6 +576,78 @@ export function main() {
 
     });
 
+    describe("expansion forms", () => {
+      it("should parse an expansion form", () => {
+        expect(tokenizeAndHumanizeParts('{one.two, three, =4 {four} =5 {five} }', true))
+            .toEqual([
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'one.two'],
+              [HtmlTokenType.RAW_TEXT, 'three'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '4'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'four'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '5'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'five'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.EOF]
+            ]);
+      });
+
+      it("should parse an expansion form with text elements surrounding it", () => {
+        expect(tokenizeAndHumanizeParts('before{one.two, three, =4 {four}}after', true))
+            .toEqual([
+              [HtmlTokenType.TEXT, "before"],
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'one.two'],
+              [HtmlTokenType.RAW_TEXT, 'three'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '4'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'four'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.TEXT, "after"],
+              [HtmlTokenType.EOF]
+            ]);
+      });
+
+      it("should parse an expansion forms with elements in it", () => {
+        expect(tokenizeAndHumanizeParts('{one.two, three, =4 {four <b>a</b>}}', true))
+            .toEqual([
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'one.two'],
+              [HtmlTokenType.RAW_TEXT, 'three'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '4'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'four '],
+              [HtmlTokenType.TAG_OPEN_START, null, 'b'],
+              [HtmlTokenType.TAG_OPEN_END],
+              [HtmlTokenType.TEXT, 'a'],
+              [HtmlTokenType.TAG_CLOSE, null, 'b'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.EOF]
+            ]);
+      });
+
+      it("should parse an expansion forms with interpolation in it", () => {
+        expect(tokenizeAndHumanizeParts('{one.two, three, =4 {four {{a}}}}', true))
+            .toEqual([
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'one.two'],
+              [HtmlTokenType.RAW_TEXT, 'three'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '4'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'four {{a}}'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.EOF]
+            ]);
+      });
+    });
+
     describe('errors', () => {
       it('should include 2 lines of context in message', () => {
         let src = "111\n222\n333\nE\n444\n555\n666\n";
@@ -604,8 +676,9 @@ export function main() {
   });
 }
 
-function tokenizeWithoutErrors(input: string): HtmlToken[] {
-  var tokenizeResult = tokenizeHtml(input, 'someUrl');
+function tokenizeWithoutErrors(input: string,
+                               tokenizeExpansionForms: boolean = false): HtmlToken[] {
+  var tokenizeResult = tokenizeHtml(input, 'someUrl', tokenizeExpansionForms);
   if (tokenizeResult.errors.length > 0) {
     var errorString = tokenizeResult.errors.join('\n');
     throw new BaseException(`Unexpected parse errors:\n${errorString}`);
@@ -613,8 +686,9 @@ function tokenizeWithoutErrors(input: string): HtmlToken[] {
   return tokenizeResult.tokens;
 }
 
-function tokenizeAndHumanizeParts(input: string): any[] {
-  return tokenizeWithoutErrors(input).map(token => [<any>token.type].concat(token.parts));
+function tokenizeAndHumanizeParts(input: string, tokenizeExpansionForms: boolean = false): any[] {
+  return tokenizeWithoutErrors(input, tokenizeExpansionForms)
+      .map(token => [<any>token.type].concat(token.parts));
 }
 
 function tokenizeAndHumanizeSourceSpans(input: string): any[] {

From 2db53cb09152d0755024eac22f9c686f0b3888fc Mon Sep 17 00:00:00 2001
From: vsavkin <avix1000@gmail.com>
Date: Tue, 12 Apr 2016 11:46:39 -0700
Subject: [PATCH 2/5] feat(html_parser): support special forms used by i18n {
 exp, plural, =0 {} }

---
 modules/angular2/src/compiler/html_parser.ts  | 74 ++++++++++++++++++-
 .../test/compiler/html_parser_spec.ts         | 54 +++++++++++++-
 2 files changed, 123 insertions(+), 5 deletions(-)

diff --git a/modules/angular2/src/compiler/html_parser.ts b/modules/angular2/src/compiler/html_parser.ts
index 40385eb1055a..56b522f559b9 100644
--- a/modules/angular2/src/compiler/html_parser.ts
+++ b/modules/angular2/src/compiler/html_parser.ts
@@ -11,7 +11,15 @@ import {
 
 import {ListWrapper} from 'angular2/src/facade/collection';
 
-import {HtmlAst, HtmlAttrAst, HtmlTextAst, HtmlCommentAst, HtmlElementAst} from './html_ast';
+import {
+  HtmlAst,
+  HtmlAttrAst,
+  HtmlTextAst,
+  HtmlCommentAst,
+  HtmlElementAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst
+} from './html_ast';
 
 import {Injectable} from 'angular2/src/core/di';
 import {HtmlToken, HtmlTokenType, tokenizeHtml} from './html_lexer';
@@ -32,8 +40,9 @@ export class HtmlParseTreeResult {
 
 @Injectable()
 export class HtmlParser {
-  parse(sourceContent: string, sourceUrl: string): HtmlParseTreeResult {
-    var tokensAndErrors = tokenizeHtml(sourceContent, sourceUrl);
+  parse(sourceContent: string, sourceUrl: string,
+        parseExpansionForms: boolean = false): HtmlParseTreeResult {
+    var tokensAndErrors = tokenizeHtml(sourceContent, sourceUrl, parseExpansionForms);
     var treeAndErrors = new TreeBuilder(tokensAndErrors.tokens).build();
     return new HtmlParseTreeResult(treeAndErrors.rootNodes, (<ParseError[]>tokensAndErrors.errors)
                                                                 .concat(treeAndErrors.errors));
@@ -68,6 +77,8 @@ class TreeBuilder {
                  this.peek.type === HtmlTokenType.ESCAPABLE_RAW_TEXT) {
         this._closeVoidElement();
         this._consumeText(this._advance());
+      } else if (this.peek.type === HtmlTokenType.EXPANSION_FORM_START) {
+        this._consumeExpansion(this._advance());
       } else {
         // Skip all other tokens...
         this._advance();
@@ -105,6 +116,63 @@ class TreeBuilder {
     this._addToParent(new HtmlCommentAst(value, token.sourceSpan));
   }
 
+  private _consumeExpansion(token: HtmlToken) {
+    let switchValue = this._advance();
+
+    let type = this._advance();
+    let cases = [];
+
+    // read =
+    while (this.peek.type === HtmlTokenType.EXPANSION_CASE_VALUE) {
+      let value = this._advance();
+
+      // read {
+      let exp = [];
+      if (this.peek.type !== HtmlTokenType.EXPANSION_CASE_EXP_START) {
+        this.errors.push(HtmlTreeError.create(null, this.peek.sourceSpan,
+                                              `Invalid expansion form. Missing '{'.,`));
+        return;
+      }
+
+      // read until }
+      let start = this._advance();
+      while (this.peek.type !== HtmlTokenType.EXPANSION_CASE_EXP_END) {
+        exp.push(this._advance());
+        if (this.peek.type === HtmlTokenType.EOF) {
+          this.errors.push(
+              HtmlTreeError.create(null, start.sourceSpan, `Invalid expansion form. Missing '}'.`));
+          return;
+        }
+      }
+      let end = this._advance();
+      exp.push(new HtmlToken(HtmlTokenType.EOF, [], end.sourceSpan));
+
+      // parse everything in between { and }
+      let parsedExp = new TreeBuilder(exp).build();
+      if (parsedExp.errors.length > 0) {
+        this.errors = this.errors.concat(parsedExp.errors);
+        return;
+      }
+
+      let sourceSpan = new ParseSourceSpan(value.sourceSpan.start, end.sourceSpan.end);
+      let expSourceSpan = new ParseSourceSpan(start.sourceSpan.start, end.sourceSpan.end);
+      cases.push(new HtmlExpansionCaseAst(value.parts[0], parsedExp.rootNodes, sourceSpan,
+                                          value.sourceSpan, expSourceSpan));
+    }
+
+    // read the final }
+    if (this.peek.type !== HtmlTokenType.EXPANSION_FORM_END) {
+      this.errors.push(
+          HtmlTreeError.create(null, this.peek.sourceSpan, `Invalid expansion form. Missing '}'.`));
+      return;
+    }
+    this._advance();
+
+    let mainSourceSpan = new ParseSourceSpan(token.sourceSpan.start, this.peek.sourceSpan.end);
+    this._addToParent(new HtmlExpansionAst(switchValue.parts[0], type.parts[0], cases,
+                                           mainSourceSpan, switchValue.sourceSpan));
+  }
+
   private _consumeText(token: HtmlToken) {
     let text = token.parts[0];
     if (text.length > 0 && text[0] == '\n') {
diff --git a/modules/angular2/test/compiler/html_parser_spec.ts b/modules/angular2/test/compiler/html_parser_spec.ts
index 3af628f315eb..403deb3d4f2d 100644
--- a/modules/angular2/test/compiler/html_parser_spec.ts
+++ b/modules/angular2/test/compiler/html_parser_spec.ts
@@ -18,7 +18,9 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
-  htmlVisitAll
+  htmlVisitAll,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst
 } from 'angular2/src/compiler/html_ast';
 import {ParseError, ParseLocation} from 'angular2/src/compiler/parse_util';
 import {humanizeDom, humanizeDomSourceSpans, humanizeLineColumn} from './html_ast_spec_utils';
@@ -227,7 +229,7 @@ export function main() {
               .toEqual([[HtmlElementAst, 'template', 0], [HtmlAttrAst, 'k', 'v']]);
         });
 
-        it('should support mamespace', () => {
+        it('should support namespace', () => {
           expect(humanizeDom(parser.parse('<svg:use xlink:href="Port" />', 'TestComp')))
               .toEqual([[HtmlElementAst, '@svg:use', 0], [HtmlAttrAst, '@xlink:href', 'Port']]);
         });
@@ -240,6 +242,54 @@ export function main() {
         });
       });
 
+      describe("expansion forms", () => {
+        it("should parse out expansion forms", () => {
+          let parsed = parser.parse(`<div>before{messages.length, plural, =0 {You have <b>no</b> messages} =1 {One {{message}}}}after</div>`,
+                                    'TestComp', true);
+
+          expect(humanizeDom(parsed))
+              .toEqual([
+                [HtmlElementAst, 'div', 0],
+                [HtmlTextAst, 'before', 1],
+                [HtmlExpansionAst, 'messages.length', 'plural'],
+                [HtmlExpansionCaseAst, '0'],
+                [HtmlExpansionCaseAst, '1'],
+                [HtmlTextAst, 'after', 1]
+              ]);
+
+          let cases = (<any>parsed.rootNodes[0]).children[1].cases;
+
+          expect(humanizeDom(new HtmlParseTreeResult(cases[0].expression, [])))
+              .toEqual([
+                [HtmlTextAst, 'You have ', 0],
+                [HtmlElementAst, 'b', 0],
+                [HtmlTextAst, 'no', 1],
+                [HtmlTextAst, ' messages', 0],
+              ]);
+
+          expect(humanizeDom(new HtmlParseTreeResult(cases[1].expression, [])))
+              .toEqual([[HtmlTextAst, 'One {{message}}', 0]]);
+        });
+
+        it("should error when expansion form is not closed", () => {
+          let p = parser.parse(`{messages.length, plural, =0 {one}`, 'TestComp', true);
+          expect(humanizeErrors(p.errors))
+              .toEqual([[null, "Invalid expansion form. Missing '}'.", '0:34']]);
+        });
+
+        it("should error when expansion case is not closed", () => {
+          let p = parser.parse(`{messages.length, plural, =0 {one`, 'TestComp', true);
+          expect(humanizeErrors(p.errors))
+              .toEqual([[null, "Invalid expansion form. Missing '}'.", '0:29']]);
+        });
+
+        it("should error when invalid html in the case", () => {
+          let p = parser.parse(`{messages.length, plural, =0 {<b/>}`, 'TestComp', true);
+          expect(humanizeErrors(p.errors))
+              .toEqual([['b', 'Only void and foreign elements can be self closed "b"', '0:30']]);
+        });
+      });
+
       describe('source spans', () => {
         it('should store the location', () => {
           expect(humanizeDomSourceSpans(parser.parse(

From be1ced5b1065a891c1898dd5d49a379f6162dac3 Mon Sep 17 00:00:00 2001
From: vsavkin <avix1000@gmail.com>
Date: Tue, 12 Apr 2016 11:46:49 -0700
Subject: [PATCH 3/5] feat(i18n): support plural and gender special forms

---
 .../src/compiler/directive_normalizer.ts      |  5 +
 modules/angular2/src/compiler/html_ast.ts     | 20 ++++
 .../angular2/src/compiler/legacy_template.ts  | 14 ++-
 .../angular2/src/compiler/template_parser.ts  |  7 +-
 modules/angular2/src/i18n/expander.ts         | 95 +++++++++++++++++++
 modules/angular2/src/i18n/i18n_html_parser.ts | 19 +++-
 .../angular2/src/i18n/message_extractor.ts    | 10 +-
 modules/angular2/src/i18n/shared.ts           |  6 ++
 .../test/compiler/html_ast_spec_utils.ts      | 15 +++
 .../test/i18n/i18n_html_parser_spec.ts        | 78 ++++++++++++++-
 .../test/i18n/message_extractor_spec.ts       | 18 ++++
 11 files changed, 278 insertions(+), 9 deletions(-)
 create mode 100644 modules/angular2/src/i18n/expander.ts

diff --git a/modules/angular2/src/compiler/directive_normalizer.ts b/modules/angular2/src/compiler/directive_normalizer.ts
index e6d440c9ebe6..5ffabda9ace6 100644
--- a/modules/angular2/src/compiler/directive_normalizer.ts
+++ b/modules/angular2/src/compiler/directive_normalizer.ts
@@ -23,6 +23,8 @@ import {
   HtmlAttrAst,
   HtmlAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from './html_ast';
 import {HtmlParser} from './html_parser';
@@ -158,4 +160,7 @@ class TemplatePreparseVisitor implements HtmlAstVisitor {
   visitComment(ast: HtmlCommentAst, context: any): any { return null; }
   visitAttr(ast: HtmlAttrAst, context: any): any { return null; }
   visitText(ast: HtmlTextAst, context: any): any { return null; }
+  visitExpansion(ast: HtmlExpansionAst, context: any): any { return null; }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return null; }
 }
diff --git a/modules/angular2/src/compiler/html_ast.ts b/modules/angular2/src/compiler/html_ast.ts
index d1f18b47dfad..6da9687043de 100644
--- a/modules/angular2/src/compiler/html_ast.ts
+++ b/modules/angular2/src/compiler/html_ast.ts
@@ -12,6 +12,24 @@ export class HtmlTextAst implements HtmlAst {
   visit(visitor: HtmlAstVisitor, context: any): any { return visitor.visitText(this, context); }
 }
 
+export class HtmlExpansionAst implements HtmlAst {
+  constructor(public switchValue: string, public type: string, public cases: HtmlExpansionCaseAst[],
+              public sourceSpan: ParseSourceSpan, public switchValueSourceSpan: ParseSourceSpan) {}
+  visit(visitor: HtmlAstVisitor, context: any): any {
+    return visitor.visitExpansion(this, context);
+  }
+}
+
+export class HtmlExpansionCaseAst implements HtmlAst {
+  constructor(public value: string, public expression: HtmlAst[],
+              public sourceSpan: ParseSourceSpan, public valueSourceSpan: ParseSourceSpan,
+              public expSourceSpan: ParseSourceSpan) {}
+
+  visit(visitor: HtmlAstVisitor, context: any): any {
+    return visitor.visitExpansionCase(this, context);
+  }
+}
+
 export class HtmlAttrAst implements HtmlAst {
   constructor(public name: string, public value: string, public sourceSpan: ParseSourceSpan) {}
   visit(visitor: HtmlAstVisitor, context: any): any { return visitor.visitAttr(this, context); }
@@ -34,6 +52,8 @@ export interface HtmlAstVisitor {
   visitAttr(ast: HtmlAttrAst, context: any): any;
   visitText(ast: HtmlTextAst, context: any): any;
   visitComment(ast: HtmlCommentAst, context: any): any;
+  visitExpansion(ast: HtmlExpansionAst, context: any): any;
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any;
 }
 
 export function htmlVisitAll(visitor: HtmlAstVisitor, asts: HtmlAst[], context: any = null): any[] {
diff --git a/modules/angular2/src/compiler/legacy_template.ts b/modules/angular2/src/compiler/legacy_template.ts
index 6adbf78a4a46..d26b9e8ac171 100644
--- a/modules/angular2/src/compiler/legacy_template.ts
+++ b/modules/angular2/src/compiler/legacy_template.ts
@@ -14,6 +14,8 @@ import {
   HtmlElementAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   HtmlAst
 } from './html_ast';
 import {HtmlParser, HtmlParseTreeResult} from './html_parser';
@@ -84,6 +86,13 @@ export class LegacyHtmlAstTransformer implements HtmlAstVisitor {
 
   visitText(ast: HtmlTextAst, context: any): HtmlTextAst { return ast; }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any {
+    let cases = ast.cases.map(c => c.visit(this, null));
+    return new HtmlExpansionAst(ast.switchValue, ast.type, cases, ast.sourceSpan);
+  }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return ast; }
+
   private _rewriteLongSyntax(ast: HtmlAttrAst): HtmlAttrAst {
     let m = RegExpWrapper.firstMatch(LONG_SYNTAX_REGEXP, ast.name);
     let attrName = ast.name;
@@ -211,9 +220,10 @@ export class LegacyHtmlAstTransformer implements HtmlAstVisitor {
 
 @Injectable()
 export class LegacyHtmlParser extends HtmlParser {
-  parse(sourceContent: string, sourceUrl: string): HtmlParseTreeResult {
+  parse(sourceContent: string, sourceUrl: string,
+        parseExpansionForms: boolean = false): HtmlParseTreeResult {
     let transformer = new LegacyHtmlAstTransformer();
-    let htmlParseTreeResult = super.parse(sourceContent, sourceUrl);
+    let htmlParseTreeResult = super.parse(sourceContent, sourceUrl, parseExpansionForms);
 
     let rootNodes = htmlParseTreeResult.rootNodes.map(node => node.visit(transformer, null));
 
diff --git a/modules/angular2/src/compiler/template_parser.ts b/modules/angular2/src/compiler/template_parser.ts
index 1c08e1589404..1c332773f32a 100644
--- a/modules/angular2/src/compiler/template_parser.ts
+++ b/modules/angular2/src/compiler/template_parser.ts
@@ -64,6 +64,8 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from './html_ast';
 
@@ -268,7 +270,7 @@ class TemplateParseVisitor implements HtmlAstVisitor {
 
   visitComment(ast: HtmlCommentAst, context: any): any { return null; }
 
-  visitElement(element: HtmlElementAst, parent: ElementContext): any {
+  visitElement(element: HtmlElementAst, component: ElementContext): any {
     var nodeName = element.name;
     var preparsedElement = preparseElement(element);
     if (preparsedElement.type === PreparsedElementType.SCRIPT ||
@@ -770,6 +772,9 @@ class NonBindableVisitor implements HtmlAstVisitor {
     var ngContentIndex = parent.findNgContentIndex(TEXT_CSS_SELECTOR);
     return new TextAst(ast.value, ngContentIndex, ast.sourceSpan);
   }
+  visitExpansion(ast: HtmlExpansionAst, context: any): any { return ast; }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return ast; }
 }
 
 class BoundElementOrDirectiveProperty {
diff --git a/modules/angular2/src/i18n/expander.ts b/modules/angular2/src/i18n/expander.ts
new file mode 100644
index 000000000000..6a27dd637340
--- /dev/null
+++ b/modules/angular2/src/i18n/expander.ts
@@ -0,0 +1,95 @@
+import {
+  HtmlAst,
+  HtmlAstVisitor,
+  HtmlElementAst,
+  HtmlAttrAst,
+  HtmlTextAst,
+  HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
+  htmlVisitAll
+} from 'angular2/src/compiler/html_ast';
+
+import {BaseException} from 'angular2/src/facade/exceptions';
+
+/**
+ * Expands special forms into elements.
+ *
+ * For example,
+ *
+ * ```
+ * { messages.length, plural,
+ *   =0 {zero}
+ *   =1 {one}
+ *   =other {more than one}
+ * }
+ * ```
+ *
+ * will be expanded into
+ *
+ * ```
+ * <ul [ngPlural]="messages.length">
+ *   <template [ngPluralCase]="0"><li i18n="plural_0">zero</li></template>
+ *   <template [ngPluralCase]="1"><li i18n="plural_1">one</li></template>
+ *   <template [ngPluralCase]="other"><li i18n="plural_other">more than one</li></template>
+ * </ul>
+ * ```
+ */
+export class Expander implements HtmlAstVisitor {
+  constructor() {}
+
+  visitElement(ast: HtmlElementAst, context: any): any {
+    return new HtmlElementAst(ast.name, ast.attrs, htmlVisitAll(this, ast.children), ast.sourceSpan,
+                              ast.startSourceSpan, ast.endSourceSpan);
+  }
+
+  visitAttr(ast: HtmlAttrAst, context: any): any { return ast; }
+
+  visitText(ast: HtmlTextAst, context: any): any { return ast; }
+
+  visitComment(ast: HtmlCommentAst, context: any): any { return ast; }
+
+  visitExpansion(ast: HtmlExpansionAst, context: any): any {
+    return ast.type == "plural" ? _expandPluralForm(ast) : _expandDefaultForm(ast);
+  }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any {
+    throw new BaseException("Should not be reached");
+  }
+}
+
+function _expandPluralForm(ast: HtmlExpansionAst): HtmlElementAst {
+  let children = ast.cases.map(
+      c => new HtmlElementAst(
+          `template`,
+          [
+            new HtmlAttrAst("[ngPluralCase]", c.value, c.valueSourceSpan),
+          ],
+          [
+            new HtmlElementAst(
+                `li`, [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)],
+                c.expression, c.sourceSpan, c.sourceSpan, c.sourceSpan)
+          ],
+          c.sourceSpan, c.sourceSpan, c.sourceSpan));
+  let switchAttr = new HtmlAttrAst("[ngPlural]", ast.switchValue, ast.switchValueSourceSpan);
+  return new HtmlElementAst("ul", [switchAttr], children, ast.sourceSpan, ast.sourceSpan,
+                            ast.sourceSpan);
+}
+
+function _expandDefaultForm(ast: HtmlExpansionAst): HtmlElementAst {
+  let children = ast.cases.map(
+      c => new HtmlElementAst(
+          `template`,
+          [
+            new HtmlAttrAst("[ngSwitchWhen]", c.value, c.valueSourceSpan),
+          ],
+          [
+            new HtmlElementAst(
+                `li`, [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)],
+                c.expression, c.sourceSpan, c.sourceSpan, c.sourceSpan)
+          ],
+          c.sourceSpan, c.sourceSpan, c.sourceSpan));
+  let switchAttr = new HtmlAttrAst("[ngSwitch]", ast.switchValue, ast.switchValueSourceSpan);
+  return new HtmlElementAst("ul", [switchAttr], children, ast.sourceSpan, ast.sourceSpan,
+                            ast.sourceSpan);
+}
\ No newline at end of file
diff --git a/modules/angular2/src/i18n/i18n_html_parser.ts b/modules/angular2/src/i18n/i18n_html_parser.ts
index a009192df8d5..23b09735a050 100644
--- a/modules/angular2/src/i18n/i18n_html_parser.ts
+++ b/modules/angular2/src/i18n/i18n_html_parser.ts
@@ -7,6 +7,8 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from 'angular2/src/compiler/html_ast';
 import {ListWrapper, StringMapWrapper} from 'angular2/src/facade/collection';
@@ -14,6 +16,7 @@ import {RegExpWrapper, NumberWrapper, isPresent} from 'angular2/src/facade/lang'
 import {BaseException} from 'angular2/src/facade/exceptions';
 import {Parser} from 'angular2/src/compiler/expression_parser/parser';
 import {Message, id} from './message';
+import {Expander} from './expander';
 import {
   messageFromAttribute,
   I18nError,
@@ -119,19 +122,25 @@ export class I18nHtmlParser implements HtmlParser {
   constructor(private _htmlParser: HtmlParser, private _parser: Parser,
               private _messagesContent: string, private _messages: {[key: string]: HtmlAst[]}) {}
 
-  parse(sourceContent: string, sourceUrl: string): HtmlParseTreeResult {
+  parse(sourceContent: string, sourceUrl: string,
+        parseExpansionForms: boolean = false): HtmlParseTreeResult {
     this.errors = [];
 
-    let res = this._htmlParser.parse(sourceContent, sourceUrl);
+    let res = this._htmlParser.parse(sourceContent, sourceUrl, parseExpansionForms);
     if (res.errors.length > 0) {
       return res;
     } else {
-      let nodes = this._recurse(res.rootNodes);
+      let nodes = this._recurse(this._expandNodes(res.rootNodes));
       return this.errors.length > 0 ? new HtmlParseTreeResult([], this.errors) :
                                       new HtmlParseTreeResult(nodes, []);
     }
   }
 
+  private _expandNodes(nodes: HtmlAst[]): HtmlAst[] {
+    let e = new Expander();
+    return htmlVisitAll(e, nodes);
+  }
+
   private _processI18nPart(p: Part): HtmlAst[] {
     try {
       return p.hasI18n ? this._mergeI18Part(p) : this._recurseIntoI18nPart(p);
@@ -360,5 +369,9 @@ class _CreateNodeMapping implements HtmlAstVisitor {
     return null;
   }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any { return null; }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return null; }
+
   visitComment(ast: HtmlCommentAst, context: any): any { return ""; }
 }
diff --git a/modules/angular2/src/i18n/message_extractor.ts b/modules/angular2/src/i18n/message_extractor.ts
index a923aae4ac6b..7da4ee0f79e3 100644
--- a/modules/angular2/src/i18n/message_extractor.ts
+++ b/modules/angular2/src/i18n/message_extractor.ts
@@ -13,6 +13,7 @@ import {isPresent, isBlank} from 'angular2/src/facade/lang';
 import {StringMapWrapper} from 'angular2/src/facade/collection';
 import {Parser} from 'angular2/src/compiler/expression_parser/parser';
 import {Message, id} from './message';
+import {Expander} from './expander';
 import {
   I18nError,
   Part,
@@ -121,15 +122,20 @@ export class MessageExtractor {
     this.messages = [];
     this.errors = [];
 
-    let res = this._htmlParser.parse(template, sourceUrl);
+    let res = this._htmlParser.parse(template, sourceUrl, true);
     if (res.errors.length > 0) {
       return new ExtractionResult([], res.errors);
     } else {
-      this._recurse(res.rootNodes);
+      this._recurse(this._expandNodes(res.rootNodes));
       return new ExtractionResult(this.messages, this.errors);
     }
   }
 
+  private _expandNodes(nodes: HtmlAst[]): HtmlAst[] {
+    let e = new Expander();
+    return htmlVisitAll(e, nodes);
+  }
+
   private _extractMessagesFromPart(p: Part): void {
     if (p.hasI18n) {
       this.messages.push(p.createMessage(this._parser));
diff --git a/modules/angular2/src/i18n/shared.ts b/modules/angular2/src/i18n/shared.ts
index d1ebd8a7a2ff..d46798f75db3 100644
--- a/modules/angular2/src/i18n/shared.ts
+++ b/modules/angular2/src/i18n/shared.ts
@@ -6,6 +6,8 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from 'angular2/src/compiler/html_ast';
 import {isPresent, isBlank, StringWrapper} from 'angular2/src/facade/lang';
@@ -179,6 +181,10 @@ class _StringifyVisitor implements HtmlAstVisitor {
 
   visitComment(ast: HtmlCommentAst, context: any): any { return ""; }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any { return null; }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return null; }
+
   private _join(strs: string[], str: string): string {
     return strs.filter(s => s.length > 0).join(str);
   }
diff --git a/modules/angular2/test/compiler/html_ast_spec_utils.ts b/modules/angular2/test/compiler/html_ast_spec_utils.ts
index a59476917fa5..af58c224f66d 100644
--- a/modules/angular2/test/compiler/html_ast_spec_utils.ts
+++ b/modules/angular2/test/compiler/html_ast_spec_utils.ts
@@ -6,6 +6,8 @@ import {
   HtmlAttrAst,
   HtmlTextAst,
   HtmlCommentAst,
+  HtmlExpansionAst,
+  HtmlExpansionCaseAst,
   htmlVisitAll
 } from 'angular2/src/compiler/html_ast';
 import {ParseError, ParseLocation} from 'angular2/src/compiler/parse_util';
@@ -70,6 +72,19 @@ class _Humanizer implements HtmlAstVisitor {
     return null;
   }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any {
+    var res = this._appendContext(ast, [HtmlExpansionAst, ast.switchValue, ast.type]);
+    this.result.push(res);
+    htmlVisitAll(this, ast.cases);
+    return null;
+  }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any {
+    var res = this._appendContext(ast, [HtmlExpansionCaseAst, ast.value]);
+    this.result.push(res);
+    return null;
+  }
+
   private _appendContext(ast: HtmlAst, input: any[]): any[] {
     if (!this.includeSourceSpan) return input;
     input.push(ast.sourceSpan.toString());
diff --git a/modules/angular2/test/i18n/i18n_html_parser_spec.ts b/modules/angular2/test/i18n/i18n_html_parser_spec.ts
index 68c505fc57b1..65ebe42450fb 100644
--- a/modules/angular2/test/i18n/i18n_html_parser_spec.ts
+++ b/modules/angular2/test/i18n/i18n_html_parser_spec.ts
@@ -42,7 +42,7 @@ export function main() {
       let res = deserializeXmb(`<message-bundle>${msgs}</message-bundle>`, 'someUrl');
 
       return new I18nHtmlParser(htmlParser, parser, res.content, res.messages)
-          .parse(template, "someurl");
+          .parse(template, "someurl", true);
     }
 
     it("should delegate to the provided parser when no i18n", () => {
@@ -188,6 +188,82 @@ export function main() {
       expect(res[1].sourceSpan.start.offset).toEqual(10);
     });
 
+    it("should handle the plural special form", () => {
+      let translations: {[key: string]: string} = {};
+      translations[id(new Message('zero<ph name="e1">bold</ph>', "plural_0", null))] =
+          'ZERO<ph name="e1">BOLD</ph>';
+
+      let res = parse(`{messages.length, plural,=0 {zero<b>bold</b>}}`, translations);
+
+      expect(humanizeDom(res))
+          .toEqual([
+            [HtmlElementAst, 'ul', 0],
+            [HtmlAttrAst, '[ngPlural]', 'messages.length'],
+            [HtmlElementAst, 'template', 1],
+            [HtmlAttrAst, '[ngPluralCase]', '0'],
+            [HtmlElementAst, 'li', 2],
+            [HtmlTextAst, 'ZERO', 3],
+            [HtmlElementAst, 'b', 3],
+            [HtmlTextAst, 'BOLD', 4]
+          ]);
+    });
+
+    it("should correctly set source code positions", () => {
+      let translations: {[key: string]: string} = {};
+      translations[id(new Message('<ph name="e0">bold</ph>', "plural_0", null))] =
+          '<ph name="e0">BOLD</ph>';
+
+      let nodes = parse(`{messages.length, plural,=0 {<b>bold</b>}}`, translations).rootNodes;
+
+      let ul: HtmlElementAst = <HtmlElementAst>nodes[0];
+
+      expect(ul.sourceSpan.start.col).toEqual(0);
+      expect(ul.sourceSpan.end.col).toEqual(42);
+
+      expect(ul.startSourceSpan.start.col).toEqual(0);
+      expect(ul.startSourceSpan.end.col).toEqual(42);
+
+      expect(ul.endSourceSpan.start.col).toEqual(0);
+      expect(ul.endSourceSpan.end.col).toEqual(42);
+
+      let switchExp = ul.attrs[0];
+      expect(switchExp.sourceSpan.start.col).toEqual(1);
+      expect(switchExp.sourceSpan.end.col).toEqual(16);
+
+      let template: HtmlElementAst = <HtmlElementAst>ul.children[0];
+      expect(template.sourceSpan.start.col).toEqual(26);
+      expect(template.sourceSpan.end.col).toEqual(41);
+
+      let switchCheck = template.attrs[0];
+      expect(switchCheck.sourceSpan.start.col).toEqual(26);
+      expect(switchCheck.sourceSpan.end.col).toEqual(28);
+
+      let li: HtmlElementAst = <HtmlElementAst>template.children[0];
+      expect(li.sourceSpan.start.col).toEqual(26);
+      expect(li.sourceSpan.end.col).toEqual(41);
+
+      let b: HtmlElementAst = <HtmlElementAst>li.children[0];
+      expect(b.sourceSpan.start.col).toEqual(29);
+      expect(b.sourceSpan.end.col).toEqual(32);
+    });
+
+    it("should handle other special forms", () => {
+      let translations: {[key: string]: string} = {};
+      translations[id(new Message('m', "gender_male", null))] = 'M';
+
+      let res = parse(`{person.gender, gender,=male {m}}`, translations);
+
+      expect(humanizeDom(res))
+          .toEqual([
+            [HtmlElementAst, 'ul', 0],
+            [HtmlAttrAst, '[ngSwitch]', 'person.gender'],
+            [HtmlElementAst, 'template', 1],
+            [HtmlAttrAst, '[ngSwitchWhen]', 'male'],
+            [HtmlElementAst, 'li', 2],
+            [HtmlTextAst, 'M', 3],
+          ]);
+    });
+
     describe("errors", () => {
       it("should error when giving an invalid template", () => {
         expect(humanizeErrors(parse("<a>a</b>", {}).errors))
diff --git a/modules/angular2/test/i18n/message_extractor_spec.ts b/modules/angular2/test/i18n/message_extractor_spec.ts
index f7f8541ad597..430b62416183 100644
--- a/modules/angular2/test/i18n/message_extractor_spec.ts
+++ b/modules/angular2/test/i18n/message_extractor_spec.ts
@@ -176,6 +176,24 @@ export function main() {
           ]);
     });
 
+    it("should extract messages from special forms", () => {
+      let res = extractor.extract(`
+        <div>
+          {messages.length, plural,
+             =0 {You have <b>no</b> messages}
+             =1 {You have one message}
+          }
+        </div>
+      `,
+                                  "someurl");
+
+      expect(res.messages)
+          .toEqual([
+            new Message('You have <ph name="e1">no</ph> messages', "plural_0", null),
+            new Message('You have one message', "plural_1", null)
+          ]);
+    });
+
     it("should remove duplicate messages", () => {
       let res = extractor.extract(`
          <!-- i18n: meaning|desc1 -->message<!-- /i18n -->

From be4afc10382d7749308c438e5906cdd706b8bcbc Mon Sep 17 00:00:00 2001
From: vsavkin <avix1000@gmail.com>
Date: Tue, 12 Apr 2016 12:03:38 -0700
Subject: [PATCH 4/5] cleanup(html_parser): cleanup to fix analyzer warnings

---
 modules/angular2/src/compiler/html_parser.ts     | 2 +-
 modules/angular2/src/compiler/legacy_template.ts | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/modules/angular2/src/compiler/html_parser.ts b/modules/angular2/src/compiler/html_parser.ts
index 56b522f559b9..0bd124cbe4ab 100644
--- a/modules/angular2/src/compiler/html_parser.ts
+++ b/modules/angular2/src/compiler/html_parser.ts
@@ -150,7 +150,7 @@ class TreeBuilder {
       // parse everything in between { and }
       let parsedExp = new TreeBuilder(exp).build();
       if (parsedExp.errors.length > 0) {
-        this.errors = this.errors.concat(parsedExp.errors);
+        this.errors = this.errors.concat(<HtmlTreeError[]>parsedExp.errors);
         return;
       }
 
diff --git a/modules/angular2/src/compiler/legacy_template.ts b/modules/angular2/src/compiler/legacy_template.ts
index d26b9e8ac171..3a58f7c7a1bd 100644
--- a/modules/angular2/src/compiler/legacy_template.ts
+++ b/modules/angular2/src/compiler/legacy_template.ts
@@ -88,7 +88,8 @@ export class LegacyHtmlAstTransformer implements HtmlAstVisitor {
 
   visitExpansion(ast: HtmlExpansionAst, context: any): any {
     let cases = ast.cases.map(c => c.visit(this, null));
-    return new HtmlExpansionAst(ast.switchValue, ast.type, cases, ast.sourceSpan);
+    return new HtmlExpansionAst(ast.switchValue, ast.type, cases, ast.sourceSpan,
+                                ast.switchValueSourceSpan);
   }
 
   visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return ast; }

From 7c5b59084ab261807c85400188aa8eaef605947c Mon Sep 17 00:00:00 2001
From: vsavkin <avix1000@gmail.com>
Date: Wed, 13 Apr 2016 16:01:25 -0700
Subject: [PATCH 5/5] feat(i18n): add support for nested expansion forms

---
 modules/angular2/src/compiler/html_lexer.ts   |  33 +++--
 modules/angular2/src/compiler/html_parser.ts  | 115 ++++++++++++------
 .../angular2/src/compiler/template_parser.ts  |   7 +-
 modules/angular2/src/i18n/expander.ts         |  71 +++++++----
 modules/angular2/src/i18n/i18n_html_parser.ts |  24 ++--
 .../angular2/src/i18n/message_extractor.ts    |   9 +-
 .../angular2/test/compiler/html_lexer_spec.ts |  25 ++++
 .../test/compiler/html_parser_spec.ts         |  21 ++++
 .../test/i18n/i18n_html_parser_spec.ts        |  35 +++++-
 9 files changed, 246 insertions(+), 94 deletions(-)

diff --git a/modules/angular2/src/compiler/html_lexer.ts b/modules/angular2/src/compiler/html_lexer.ts
index 76f48683d9ac..bedab75ca837 100644
--- a/modules/angular2/src/compiler/html_lexer.ts
+++ b/modules/angular2/src/compiler/html_lexer.ts
@@ -125,8 +125,7 @@ class _HtmlTokenizer {
   private currentTokenStart: ParseLocation;
   private currentTokenType: HtmlTokenType;
 
-  private inExpansionCase: boolean = false;
-  private inExpansionForm: boolean = false;
+  private expansionCaseStack = [];
 
   tokens: HtmlToken[] = [];
   errors: HtmlTokenError[] = [];
@@ -169,10 +168,12 @@ class _HtmlTokenizer {
         } else if (this.peek === $EQ && this.tokenizeExpansionForms) {
           this._consumeExpansionCaseStart();
 
-        } else if (this.peek === $RBRACE && this.inExpansionCase && this.tokenizeExpansionForms) {
+        } else if (this.peek === $RBRACE && this.isInExpansionCase() &&
+                   this.tokenizeExpansionForms) {
           this._consumeExpansionCaseEnd();
 
-        } else if (this.peek === $RBRACE && !this.inExpansionCase && this.tokenizeExpansionForms) {
+        } else if (this.peek === $RBRACE && this.isInExpansionForm() &&
+                   this.tokenizeExpansionForms) {
           this._consumeExpansionFormEnd();
 
         } else {
@@ -551,7 +552,7 @@ class _HtmlTokenizer {
     this._requireCharCode($COMMA);
     this._attemptCharCodeUntilFn(isNotWhitespace);
 
-    this.inExpansionForm = true;
+    this.expansionCaseStack.push(HtmlTokenType.EXPANSION_FORM_START);
   }
 
   private _consumeExpansionCaseStart() {
@@ -567,7 +568,7 @@ class _HtmlTokenizer {
     this._endToken([], this._getLocation());
     this._attemptCharCodeUntilFn(isNotWhitespace);
 
-    this.inExpansionCase = true;
+    this.expansionCaseStack.push(HtmlTokenType.EXPANSION_CASE_EXP_START);
   }
 
   private _consumeExpansionCaseEnd() {
@@ -576,7 +577,7 @@ class _HtmlTokenizer {
     this._endToken([], this._getLocation());
     this._attemptCharCodeUntilFn(isNotWhitespace);
 
-    this.inExpansionCase = false;
+    this.expansionCaseStack.pop();
   }
 
   private _consumeExpansionFormEnd() {
@@ -584,7 +585,7 @@ class _HtmlTokenizer {
     this._requireCharCode($RBRACE);
     this._endToken([]);
 
-    this.inExpansionForm = false;
+    this.expansionCaseStack.pop();
   }
 
   private _consumeText() {
@@ -622,7 +623,9 @@ class _HtmlTokenizer {
     if (this.peek === $LT || this.peek === $EOF) return true;
     if (this.tokenizeExpansionForms) {
       if (isSpecialFormStart(this.peek, this.nextPeek)) return true;
-      if (this.peek === $RBRACE && !interpolation && this.inExpansionForm) return true;
+      if (this.peek === $RBRACE && !interpolation &&
+          (this.isInExpansionCase() || this.isInExpansionForm()))
+        return true;
     }
     return false;
   }
@@ -648,6 +651,18 @@ class _HtmlTokenizer {
       this.tokens = ListWrapper.slice(this.tokens, 0, nbTokens);
     }
   }
+
+  private isInExpansionCase(): boolean {
+    return this.expansionCaseStack.length > 0 &&
+           this.expansionCaseStack[this.expansionCaseStack.length - 1] ===
+               HtmlTokenType.EXPANSION_CASE_EXP_START;
+  }
+
+  private isInExpansionForm(): boolean {
+    return this.expansionCaseStack.length > 0 &&
+           this.expansionCaseStack[this.expansionCaseStack.length - 1] ===
+               HtmlTokenType.EXPANSION_FORM_START;
+  }
 }
 
 function isNotWhitespace(code: number): boolean {
diff --git a/modules/angular2/src/compiler/html_parser.ts b/modules/angular2/src/compiler/html_parser.ts
index 0bd124cbe4ab..14437d0d9ad3 100644
--- a/modules/angular2/src/compiler/html_parser.ts
+++ b/modules/angular2/src/compiler/html_parser.ts
@@ -124,40 +124,9 @@ class TreeBuilder {
 
     // read =
     while (this.peek.type === HtmlTokenType.EXPANSION_CASE_VALUE) {
-      let value = this._advance();
-
-      // read {
-      let exp = [];
-      if (this.peek.type !== HtmlTokenType.EXPANSION_CASE_EXP_START) {
-        this.errors.push(HtmlTreeError.create(null, this.peek.sourceSpan,
-                                              `Invalid expansion form. Missing '{'.,`));
-        return;
-      }
-
-      // read until }
-      let start = this._advance();
-      while (this.peek.type !== HtmlTokenType.EXPANSION_CASE_EXP_END) {
-        exp.push(this._advance());
-        if (this.peek.type === HtmlTokenType.EOF) {
-          this.errors.push(
-              HtmlTreeError.create(null, start.sourceSpan, `Invalid expansion form. Missing '}'.`));
-          return;
-        }
-      }
-      let end = this._advance();
-      exp.push(new HtmlToken(HtmlTokenType.EOF, [], end.sourceSpan));
-
-      // parse everything in between { and }
-      let parsedExp = new TreeBuilder(exp).build();
-      if (parsedExp.errors.length > 0) {
-        this.errors = this.errors.concat(<HtmlTreeError[]>parsedExp.errors);
-        return;
-      }
-
-      let sourceSpan = new ParseSourceSpan(value.sourceSpan.start, end.sourceSpan.end);
-      let expSourceSpan = new ParseSourceSpan(start.sourceSpan.start, end.sourceSpan.end);
-      cases.push(new HtmlExpansionCaseAst(value.parts[0], parsedExp.rootNodes, sourceSpan,
-                                          value.sourceSpan, expSourceSpan));
+      let expCase = this._parseExpansionCase();
+      if (isBlank(expCase)) return;  // error
+      cases.push(expCase);
     }
 
     // read the final }
@@ -173,6 +142,80 @@ class TreeBuilder {
                                            mainSourceSpan, switchValue.sourceSpan));
   }
 
+  private _parseExpansionCase(): HtmlExpansionCaseAst {
+    let value = this._advance();
+
+    // read {
+    if (this.peek.type !== HtmlTokenType.EXPANSION_CASE_EXP_START) {
+      this.errors.push(HtmlTreeError.create(null, this.peek.sourceSpan,
+                                            `Invalid expansion form. Missing '{'.,`));
+      return null;
+    }
+
+    // read until }
+    let start = this._advance();
+
+    let exp = this._collectExpansionExpTokens(start);
+    if (isBlank(exp)) return null;
+
+    let end = this._advance();
+    exp.push(new HtmlToken(HtmlTokenType.EOF, [], end.sourceSpan));
+
+    // parse everything in between { and }
+    let parsedExp = new TreeBuilder(exp).build();
+    if (parsedExp.errors.length > 0) {
+      this.errors = this.errors.concat(<HtmlTreeError[]>parsedExp.errors);
+      return null;
+    }
+
+    let sourceSpan = new ParseSourceSpan(value.sourceSpan.start, end.sourceSpan.end);
+    let expSourceSpan = new ParseSourceSpan(start.sourceSpan.start, end.sourceSpan.end);
+    return new HtmlExpansionCaseAst(value.parts[0], parsedExp.rootNodes, sourceSpan,
+                                    value.sourceSpan, expSourceSpan);
+  }
+
+  private _collectExpansionExpTokens(start: HtmlToken): HtmlToken[] {
+    let exp = [];
+    let expansionFormStack = [HtmlTokenType.EXPANSION_CASE_EXP_START];
+
+    while (true) {
+      if (this.peek.type === HtmlTokenType.EXPANSION_FORM_START ||
+          this.peek.type === HtmlTokenType.EXPANSION_CASE_EXP_START) {
+        expansionFormStack.push(this.peek.type);
+      }
+
+      if (this.peek.type === HtmlTokenType.EXPANSION_CASE_EXP_END) {
+        if (lastOnStack(expansionFormStack, HtmlTokenType.EXPANSION_CASE_EXP_START)) {
+          expansionFormStack.pop();
+          if (expansionFormStack.length == 0) return exp;
+
+        } else {
+          this.errors.push(
+              HtmlTreeError.create(null, start.sourceSpan, `Invalid expansion form. Missing '}'.`));
+          return null;
+        }
+      }
+
+      if (this.peek.type === HtmlTokenType.EXPANSION_FORM_END) {
+        if (lastOnStack(expansionFormStack, HtmlTokenType.EXPANSION_FORM_START)) {
+          expansionFormStack.pop();
+        } else {
+          this.errors.push(
+              HtmlTreeError.create(null, start.sourceSpan, `Invalid expansion form. Missing '}'.`));
+          return null;
+        }
+      }
+
+      if (this.peek.type === HtmlTokenType.EOF) {
+        this.errors.push(
+            HtmlTreeError.create(null, start.sourceSpan, `Invalid expansion form. Missing '}'.`));
+        return null;
+      }
+
+      exp.push(this._advance());
+    }
+  }
+
   private _consumeText(token: HtmlToken) {
     let text = token.parts[0];
     if (text.length > 0 && text[0] == '\n') {
@@ -321,3 +364,7 @@ function getElementFullName(prefix: string, localName: string,
 
   return mergeNsAndName(prefix, localName);
 }
+
+function lastOnStack(stack: any[], element: any): boolean {
+  return stack.length > 0 && stack[stack.length - 1] === element;
+}
\ No newline at end of file
diff --git a/modules/angular2/src/compiler/template_parser.ts b/modules/angular2/src/compiler/template_parser.ts
index 1c332773f32a..0595beedd065 100644
--- a/modules/angular2/src/compiler/template_parser.ts
+++ b/modules/angular2/src/compiler/template_parser.ts
@@ -254,6 +254,10 @@ class TemplateParseVisitor implements HtmlAstVisitor {
     }
   }
 
+  visitExpansion(ast: HtmlExpansionAst, context: any): any { return null; }
+
+  visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return null; }
+
   visitText(ast: HtmlTextAst, parent: ElementContext): any {
     var ngContentIndex = parent.findNgContentIndex(TEXT_CSS_SELECTOR);
     var expr = this._parseInterpolation(ast.value, ast.sourceSpan);
@@ -270,7 +274,7 @@ class TemplateParseVisitor implements HtmlAstVisitor {
 
   visitComment(ast: HtmlCommentAst, context: any): any { return null; }
 
-  visitElement(element: HtmlElementAst, component: ElementContext): any {
+  visitElement(element: HtmlElementAst, parent: ElementContext): any {
     var nodeName = element.name;
     var preparsedElement = preparseElement(element);
     if (preparsedElement.type === PreparsedElementType.SCRIPT ||
@@ -773,7 +777,6 @@ class NonBindableVisitor implements HtmlAstVisitor {
     return new TextAst(ast.value, ngContentIndex, ast.sourceSpan);
   }
   visitExpansion(ast: HtmlExpansionAst, context: any): any { return ast; }
-
   visitExpansionCase(ast: HtmlExpansionCaseAst, context: any): any { return ast; }
 }
 
diff --git a/modules/angular2/src/i18n/expander.ts b/modules/angular2/src/i18n/expander.ts
index 6a27dd637340..6fc8127a9f18 100644
--- a/modules/angular2/src/i18n/expander.ts
+++ b/modules/angular2/src/i18n/expander.ts
@@ -12,6 +12,7 @@ import {
 
 import {BaseException} from 'angular2/src/facade/exceptions';
 
+
 /**
  * Expands special forms into elements.
  *
@@ -35,7 +36,18 @@ import {BaseException} from 'angular2/src/facade/exceptions';
  * </ul>
  * ```
  */
-export class Expander implements HtmlAstVisitor {
+export function expandNodes(nodes: HtmlAst[]): ExpansionResult {
+  let e = new _Expander();
+  let n = htmlVisitAll(e, nodes);
+  return new ExpansionResult(n, e.expanded);
+}
+
+export class ExpansionResult {
+  constructor(public nodes: HtmlAst[], public expanded: boolean) {}
+}
+
+class _Expander implements HtmlAstVisitor {
+  expanded: boolean = false;
   constructor() {}
 
   visitElement(ast: HtmlElementAst, context: any): any {
@@ -50,6 +62,7 @@ export class Expander implements HtmlAstVisitor {
   visitComment(ast: HtmlCommentAst, context: any): any { return ast; }
 
   visitExpansion(ast: HtmlExpansionAst, context: any): any {
+    this.expanded = true;
     return ast.type == "plural" ? _expandPluralForm(ast) : _expandDefaultForm(ast);
   }
 
@@ -59,36 +72,44 @@ export class Expander implements HtmlAstVisitor {
 }
 
 function _expandPluralForm(ast: HtmlExpansionAst): HtmlElementAst {
-  let children = ast.cases.map(
-      c => new HtmlElementAst(
-          `template`,
-          [
-            new HtmlAttrAst("[ngPluralCase]", c.value, c.valueSourceSpan),
-          ],
-          [
-            new HtmlElementAst(
-                `li`, [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)],
-                c.expression, c.sourceSpan, c.sourceSpan, c.sourceSpan)
-          ],
-          c.sourceSpan, c.sourceSpan, c.sourceSpan));
+  let children = ast.cases.map(c => {
+    let expansionResult = expandNodes(c.expression);
+    let i18nAttrs = expansionResult.expanded ?
+                        [] :
+                        [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)];
+
+    return new HtmlElementAst(`template`,
+                              [
+                                new HtmlAttrAst("ngPluralCase", c.value, c.valueSourceSpan),
+                              ],
+                              [
+                                new HtmlElementAst(`li`, i18nAttrs, expansionResult.nodes,
+                                                   c.sourceSpan, c.sourceSpan, c.sourceSpan)
+                              ],
+                              c.sourceSpan, c.sourceSpan, c.sourceSpan);
+  });
   let switchAttr = new HtmlAttrAst("[ngPlural]", ast.switchValue, ast.switchValueSourceSpan);
   return new HtmlElementAst("ul", [switchAttr], children, ast.sourceSpan, ast.sourceSpan,
                             ast.sourceSpan);
 }
 
 function _expandDefaultForm(ast: HtmlExpansionAst): HtmlElementAst {
-  let children = ast.cases.map(
-      c => new HtmlElementAst(
-          `template`,
-          [
-            new HtmlAttrAst("[ngSwitchWhen]", c.value, c.valueSourceSpan),
-          ],
-          [
-            new HtmlElementAst(
-                `li`, [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)],
-                c.expression, c.sourceSpan, c.sourceSpan, c.sourceSpan)
-          ],
-          c.sourceSpan, c.sourceSpan, c.sourceSpan));
+  let children = ast.cases.map(c => {
+    let expansionResult = expandNodes(c.expression);
+    let i18nAttrs = expansionResult.expanded ?
+                        [] :
+                        [new HtmlAttrAst("i18n", `${ast.type}_${c.value}`, c.valueSourceSpan)];
+
+    return new HtmlElementAst(`template`,
+                              [
+                                new HtmlAttrAst("ngSwitchWhen", c.value, c.valueSourceSpan),
+                              ],
+                              [
+                                new HtmlElementAst(`li`, i18nAttrs, expansionResult.nodes,
+                                                   c.sourceSpan, c.sourceSpan, c.sourceSpan)
+                              ],
+                              c.sourceSpan, c.sourceSpan, c.sourceSpan);
+  });
   let switchAttr = new HtmlAttrAst("[ngSwitch]", ast.switchValue, ast.switchValueSourceSpan);
   return new HtmlElementAst("ul", [switchAttr], children, ast.sourceSpan, ast.sourceSpan,
                             ast.sourceSpan);
diff --git a/modules/angular2/src/i18n/i18n_html_parser.ts b/modules/angular2/src/i18n/i18n_html_parser.ts
index 23b09735a050..bcf22061a416 100644
--- a/modules/angular2/src/i18n/i18n_html_parser.ts
+++ b/modules/angular2/src/i18n/i18n_html_parser.ts
@@ -16,7 +16,7 @@ import {RegExpWrapper, NumberWrapper, isPresent} from 'angular2/src/facade/lang'
 import {BaseException} from 'angular2/src/facade/exceptions';
 import {Parser} from 'angular2/src/compiler/expression_parser/parser';
 import {Message, id} from './message';
-import {Expander} from './expander';
+import {expandNodes} from './expander';
 import {
   messageFromAttribute,
   I18nError,
@@ -126,21 +126,16 @@ export class I18nHtmlParser implements HtmlParser {
         parseExpansionForms: boolean = false): HtmlParseTreeResult {
     this.errors = [];
 
-    let res = this._htmlParser.parse(sourceContent, sourceUrl, parseExpansionForms);
+    let res = this._htmlParser.parse(sourceContent, sourceUrl, true);
     if (res.errors.length > 0) {
       return res;
     } else {
-      let nodes = this._recurse(this._expandNodes(res.rootNodes));
+      let nodes = this._recurse(expandNodes(res.rootNodes).nodes);
       return this.errors.length > 0 ? new HtmlParseTreeResult([], this.errors) :
                                       new HtmlParseTreeResult(nodes, []);
     }
   }
 
-  private _expandNodes(nodes: HtmlAst[]): HtmlAst[] {
-    let e = new Expander();
-    return htmlVisitAll(e, nodes);
-  }
-
   private _processI18nPart(p: Part): HtmlAst[] {
     try {
       return p.hasI18n ? this._mergeI18Part(p) : this._recurseIntoI18nPart(p);
@@ -155,9 +150,11 @@ export class I18nHtmlParser implements HtmlParser {
   }
 
   private _mergeI18Part(p: Part): HtmlAst[] {
-    let messageId = id(p.createMessage(this._parser));
+    let message = p.createMessage(this._parser);
+    let messageId = id(message);
     if (!StringMapWrapper.contains(this._messages, messageId)) {
-      throw new I18nError(p.sourceSpan, `Cannot find message for id '${messageId}'`);
+      throw new I18nError(
+          p.sourceSpan, `Cannot find message for id '${messageId}', content '${message.content}'.`);
     }
 
     let parsedMessage = this._messages[messageId];
@@ -294,14 +291,17 @@ export class I18nHtmlParser implements HtmlParser {
       }
 
       let i18n = i18ns[0];
-      let messageId = id(messageFromAttribute(this._parser, el, i18n));
+      let message = messageFromAttribute(this._parser, el, i18n);
+      let messageId = id(message);
 
       if (StringMapWrapper.contains(this._messages, messageId)) {
         let updatedMessage = this._replaceInterpolationInAttr(attr, this._messages[messageId]);
         res.push(new HtmlAttrAst(attr.name, updatedMessage, attr.sourceSpan));
 
       } else {
-        throw new I18nError(attr.sourceSpan, `Cannot find message for id '${messageId}'`);
+        throw new I18nError(
+            attr.sourceSpan,
+            `Cannot find message for id '${messageId}', content '${message.content}'.`);
       }
     });
     return res;
diff --git a/modules/angular2/src/i18n/message_extractor.ts b/modules/angular2/src/i18n/message_extractor.ts
index 7da4ee0f79e3..5630d44af73e 100644
--- a/modules/angular2/src/i18n/message_extractor.ts
+++ b/modules/angular2/src/i18n/message_extractor.ts
@@ -13,7 +13,7 @@ import {isPresent, isBlank} from 'angular2/src/facade/lang';
 import {StringMapWrapper} from 'angular2/src/facade/collection';
 import {Parser} from 'angular2/src/compiler/expression_parser/parser';
 import {Message, id} from './message';
-import {Expander} from './expander';
+import {expandNodes} from './expander';
 import {
   I18nError,
   Part,
@@ -126,16 +126,11 @@ export class MessageExtractor {
     if (res.errors.length > 0) {
       return new ExtractionResult([], res.errors);
     } else {
-      this._recurse(this._expandNodes(res.rootNodes));
+      this._recurse(expandNodes(res.rootNodes).nodes);
       return new ExtractionResult(this.messages, this.errors);
     }
   }
 
-  private _expandNodes(nodes: HtmlAst[]): HtmlAst[] {
-    let e = new Expander();
-    return htmlVisitAll(e, nodes);
-  }
-
   private _extractMessagesFromPart(p: Part): void {
     if (p.hasI18n) {
       this.messages.push(p.createMessage(this._parser));
diff --git a/modules/angular2/test/compiler/html_lexer_spec.ts b/modules/angular2/test/compiler/html_lexer_spec.ts
index aef9b096587f..63f57d231d52 100644
--- a/modules/angular2/test/compiler/html_lexer_spec.ts
+++ b/modules/angular2/test/compiler/html_lexer_spec.ts
@@ -646,6 +646,31 @@ export function main() {
               [HtmlTokenType.EOF]
             ]);
       });
+
+      it("should parse nested expansion forms", () => {
+        expect(tokenizeAndHumanizeParts(`{one.two, three, =4 { {xx, yy, =x {one}} }}`, true))
+            .toEqual([
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'one.two'],
+              [HtmlTokenType.RAW_TEXT, 'three'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, '4'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+
+              [HtmlTokenType.EXPANSION_FORM_START],
+              [HtmlTokenType.RAW_TEXT, 'xx'],
+              [HtmlTokenType.RAW_TEXT, 'yy'],
+              [HtmlTokenType.EXPANSION_CASE_VALUE, 'x'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_START],
+              [HtmlTokenType.TEXT, 'one'],
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.TEXT, ' '],
+
+              [HtmlTokenType.EXPANSION_CASE_EXP_END],
+              [HtmlTokenType.EXPANSION_FORM_END],
+              [HtmlTokenType.EOF]
+            ]);
+      });
     });
 
     describe('errors', () => {
diff --git a/modules/angular2/test/compiler/html_parser_spec.ts b/modules/angular2/test/compiler/html_parser_spec.ts
index 403deb3d4f2d..945ab983aee9 100644
--- a/modules/angular2/test/compiler/html_parser_spec.ts
+++ b/modules/angular2/test/compiler/html_parser_spec.ts
@@ -271,6 +271,27 @@ export function main() {
               .toEqual([[HtmlTextAst, 'One {{message}}', 0]]);
         });
 
+        it("should parse out nested expansion forms", () => {
+          let parsed = parser.parse(`{messages.length, plural, =0 { {p.gender, gender, =m {m}} }}`,
+                                    'TestComp', true);
+
+
+          expect(humanizeDom(parsed))
+              .toEqual([
+                [HtmlExpansionAst, 'messages.length', 'plural'],
+                [HtmlExpansionCaseAst, '0'],
+              ]);
+
+          let firstCase = (<any>parsed.rootNodes[0]).cases[0];
+
+          expect(humanizeDom(new HtmlParseTreeResult(firstCase.expression, [])))
+              .toEqual([
+                [HtmlExpansionAst, 'p.gender', 'gender'],
+                [HtmlExpansionCaseAst, 'm'],
+                [HtmlTextAst, ' ', 0],
+              ]);
+        });
+
         it("should error when expansion form is not closed", () => {
           let p = parser.parse(`{messages.length, plural, =0 {one}`, 'TestComp', true);
           expect(humanizeErrors(p.errors))
diff --git a/modules/angular2/test/i18n/i18n_html_parser_spec.ts b/modules/angular2/test/i18n/i18n_html_parser_spec.ts
index 65ebe42450fb..0b4f2e93c70e 100644
--- a/modules/angular2/test/i18n/i18n_html_parser_spec.ts
+++ b/modules/angular2/test/i18n/i18n_html_parser_spec.ts
@@ -188,7 +188,7 @@ export function main() {
       expect(res[1].sourceSpan.start.offset).toEqual(10);
     });
 
-    it("should handle the plural special form", () => {
+    it("should handle the plural expansion form", () => {
       let translations: {[key: string]: string} = {};
       translations[id(new Message('zero<ph name="e1">bold</ph>', "plural_0", null))] =
           'ZERO<ph name="e1">BOLD</ph>';
@@ -200,7 +200,7 @@ export function main() {
             [HtmlElementAst, 'ul', 0],
             [HtmlAttrAst, '[ngPlural]', 'messages.length'],
             [HtmlElementAst, 'template', 1],
-            [HtmlAttrAst, '[ngPluralCase]', '0'],
+            [HtmlAttrAst, 'ngPluralCase', '0'],
             [HtmlElementAst, 'li', 2],
             [HtmlTextAst, 'ZERO', 3],
             [HtmlElementAst, 'b', 3],
@@ -208,6 +208,31 @@ export function main() {
           ]);
     });
 
+    it("should handle nested expansion forms", () => {
+      let translations: {[key: string]: string} = {};
+      translations[id(new Message('m', "gender_m", null))] = 'M';
+
+      let res = parse(`{messages.length, plural, =0 { {p.gender, gender, =m {m}} }}`, translations);
+
+      expect(humanizeDom(res))
+          .toEqual([
+            [HtmlElementAst, 'ul', 0],
+            [HtmlAttrAst, '[ngPlural]', 'messages.length'],
+            [HtmlElementAst, 'template', 1],
+            [HtmlAttrAst, 'ngPluralCase', '0'],
+            [HtmlElementAst, 'li', 2],
+
+            [HtmlElementAst, 'ul', 3],
+            [HtmlAttrAst, '[ngSwitch]', 'p.gender'],
+            [HtmlElementAst, 'template', 4],
+            [HtmlAttrAst, 'ngSwitchWhen', 'm'],
+            [HtmlElementAst, 'li', 5],
+            [HtmlTextAst, 'M', 6],
+
+            [HtmlTextAst, ' ', 3]
+          ]);
+    });
+
     it("should correctly set source code positions", () => {
       let translations: {[key: string]: string} = {};
       translations[id(new Message('<ph name="e0">bold</ph>', "plural_0", null))] =
@@ -258,7 +283,7 @@ export function main() {
             [HtmlElementAst, 'ul', 0],
             [HtmlAttrAst, '[ngSwitch]', 'person.gender'],
             [HtmlElementAst, 'template', 1],
-            [HtmlAttrAst, '[ngSwitchWhen]', 'male'],
+            [HtmlAttrAst, 'ngSwitchWhen', 'male'],
             [HtmlElementAst, 'li', 2],
             [HtmlTextAst, 'M', 3],
           ]);
@@ -273,13 +298,13 @@ export function main() {
       it("should error when no matching message (attr)", () => {
         let mid = id(new Message("some message", null, null));
         expect(humanizeErrors(parse("<div value='some message' i18n-value></div>", {}).errors))
-            .toEqual([`Cannot find message for id '${mid}'`]);
+            .toEqual([`Cannot find message for id '${mid}', content 'some message'.`]);
       });
 
       it("should error when no matching message (text)", () => {
         let mid = id(new Message("some message", null, null));
         expect(humanizeErrors(parse("<div i18n>some message</div>", {}).errors))
-            .toEqual([`Cannot find message for id '${mid}'`]);
+            .toEqual([`Cannot find message for id '${mid}', content 'some message'.`]);
       });
 
       it("should error when a non-placeholder element appears in translation", () => {