feat(i18n): implement xmb deserialization

modules/angular2/src/i18n/xmb_serializer.ts

@@ -1,12 +1,95 @@
-import {isPresent} from 'angular2/src/facade/lang';
+import {isPresent, isBlank, RegExpWrapper} from 'angular2/src/facade/lang';
+import {HtmlAst, HtmlElementAst} from 'angular2/src/compiler/html_ast';
 import {Message, id} from './message';
+import {HtmlParser} from 'angular2/src/compiler/html_parser';
+import {ParseSourceSpan, ParseError} from 'angular2/src/compiler/parse_util';
+
+let _PLACEHOLDER_REGEXP = RegExpWrapper.create(`\\<ph(\\s)+name=("(\\w)+")\\/\\>`);
+const _ID_ATTR = "id";
+const _MSG_ELEMENT = "msg";
+const _BUNDLE_ELEMENT = "message-bundle";
 
 export function serializeXmb(messages: Message[]): string {
   let ms = messages.map((m) => _serializeMessage(m)).join("");
   return `<message-bundle>${ms}</message-bundle>`;
 }
 
+export class XmbDeserializationResult {
+  constructor(public content: string, public messages: {[key: string]: HtmlAst[]},
+              public errors: ParseError[]) {}
+}
+
+export class XmbDeserializationError extends ParseError {
+  constructor(span: ParseSourceSpan, msg: string) { super(span, msg); }
+}
+
+export function deserializeXmb(content: string, url: string): XmbDeserializationResult {
+  let parser = new HtmlParser();
+  let normalizedContent = _expandPlaceholder(content.trim());
+  let parsed = parser.parse(normalizedContent, url);
+
+  if (parsed.errors.length > 0) {
+    return new XmbDeserializationResult(null, {}, parsed.errors);
+  }
+
+  if (_checkRootElement(parsed.rootNodes)) {
+    return new XmbDeserializationResult(
+        null, {}, [new XmbDeserializationError(null, `Missing element "${_BUNDLE_ELEMENT}"`)]);
+  }
+
+  let bundleEl = <HtmlElementAst>parsed.rootNodes[0];  // test this
+  let errors = [];
+  let messages: {[key: string]: HtmlAst[]} = {};
+
+  _createMessages(bundleEl.children, messages, errors);
+
+  return (errors.length == 0) ?
+             new XmbDeserializationResult(normalizedContent, messages, []) :
+             new XmbDeserializationResult(null, <{[key: string]: HtmlAst[]}>{}, errors);
+}
+
+function _checkRootElement(nodes: HtmlAst[]): boolean {
+  return nodes.length < 1 || !(nodes[0] instanceof HtmlElementAst) ||
+         (<HtmlElementAst>nodes[0]).name != _BUNDLE_ELEMENT;
+}
+
+function _createMessages(nodes: HtmlAst[], messages: {[key: string]: HtmlAst[]},
+                         errors: ParseError[]): void {
+  nodes.forEach((item) => {
+    if (item instanceof HtmlElementAst) {
+      let msg = <HtmlElementAst>item;
+
+      if (msg.name != _MSG_ELEMENT) {
+        errors.push(
+            new XmbDeserializationError(item.sourceSpan, `Unexpected element "${msg.name}"`));
+        return;
+      }
+
+      let id = _id(msg);
+      if (isBlank(id)) {
+        errors.push(
+            new XmbDeserializationError(item.sourceSpan, `"${_ID_ATTR}" attribute is missing`));
+        return;
+      }
+
+      messages[id] = msg.children;
+    }
+  });
+}
+
+function _id(el: HtmlElementAst): string {
+  let ids = el.attrs.filter(a => a.name == _ID_ATTR);
+  return ids.length > 0 ? ids[0].value : null;
+}
+
 function _serializeMessage(m: Message): string {
   let desc = isPresent(m.description) ? ` desc='${m.description}'` : "";
   return `<msg id='${id(m)}'${desc}>${m.content}</msg>`;
-}
+}
+
+function _expandPlaceholder(input: string): string {
+  return RegExpWrapper.replaceAll(_PLACEHOLDER_REGEXP, input, (match) => {
+    let nameWithQuotes = match[2];
+    return `<ph name=${nameWithQuotes}></ph>`;
+  });
+}