Bug 976556 - Parse translation results back into the TranslationDocument and TranslationItem data structures. r=florian

browser/components/translation/BingTranslator.jsm

@@ -122,8 +122,47 @@ this.BingTranslation.prototype = {
     }
   },
 
-  _parseChunkResult() {
+  /**
-    // note: this function is implemented in the patch from bug 976556
+   * This function parses the result returned by Bing's Http.svc API,
+   * which is a XML file that contains a number of elements. To our
+   * particular interest, the only part of the response that matters
+   * are the <TranslatedText> nodes, which contains the resulting
+   * items that were sent to be translated.
+   *
+   * @param   request      The request sent to the server.
+   * @returns boolean      True if parsing of this chunk was successful.
+   */
+  _parseChunkResult: function(bingRequest) {
+    let domParser = Cc["@mozilla.org/xmlextras/domparser;1"]
+                      .createInstance(Ci.nsIDOMParser);
+
+    let results;
+    try {
+      let doc = domParser.parseFromString(bingRequest.networkRequest
+                                                     .response.body, "text/xml");
+      results = doc.querySelectorAll("TranslatedText");
+    } catch (e) {
+      return false;
+    }
+
+    let len = results.length;
+    if (len != bingRequest.translationData.length) {
+      // This should never happen, but if the service returns a different number
+      // of items (from the number of items submitted), we can't use this chunk
+      // because all items would be paired incorrectly.
+      return false;
+    }
+
+    let error = false;
+    for (let i = 0; i < len; i++) {
+      try {
+        bingRequest.translationData[i][0].parseResult(
+          results[i].firstChild.nodeValue
+        );
+      } catch (e) { error = true; }
+    }
+
+    return !error;
   },
 
   /**

browser/components/translation/TranslationDocument.jsm

@@ -167,6 +167,38 @@ this.TranslationDocument.prototype = {
  * This class represents an item for translation. It's basically our
  * wrapper class around a node returned by getTranslationNode, with
  * more data and structural information on it.
+ *
+ * At the end of the translation process, besides the properties below,
+ * a TranslationItem will contain two other properties: one called "original"
+ * and one called "translation". They are twin objects, one which reflect
+ * the structure of that node in its original state, and the other in its
+ * translated state.
+ *
+ * The "original" array is generated in the generateTextForItem function,
+ * and the "translation" array is generated when the translation results
+ * are parsed.
+ *
+ * They are both arrays, which contain a mix of strings and references to
+ * child TranslationItems. The references in both arrays point to the * same *
+ * TranslationItem object, but they might appear in different orders between the
+ * "original" and "translation" arrays.
+ *
+ * An example:
+ *
+ *  English: <div id="n1">Welcome to <b id="n2">Mozilla's</b> website</div>
+ *  Portuguese: <div id="n1">Bem vindo a pagina <b id="n2">da Mozilla</b></div>
+ *
+ *  TranslationItem n1 = {
+ *    id: 1,
+ *    original: ["Welcome to", ptr to n2, "website"]
+ *    translation: ["Bem vindo a pagina", ptr to n2]
+ *  }
+ *
+ *  TranslationItem n2 = {
+ *    id: 2,
+ *    original: ["Mozilla's"],
+ *    translation: ["da Mozilla"]
+ *  }
  */
 function TranslationItem(node, id, isRoot) {
   this.nodeRef = node;
@@ -185,5 +217,83 @@ TranslationItem.prototype = {
                    : '';
     return "[object TranslationItem: <" + this.nodeRef.localName + ">"
            + rootType + "]";
+  },
+
+  /**
+   * This function will parse the result of the translation of one translation
+   * item. If this item was a simple root, all we sent was a plain-text version
+   * of it, so the result is also straightforward text.
+   *
+   * For non-simple roots, we sent a simplified HTML representation of that
+   * node, and we'll first parse that into an HTML doc and then call the
+   * parseResultNode helper function to parse it.
+   *
+   * While parsing, the result is stored in the "translation" field of the
+   * TranslationItem, which will be used to display the final translation when
+   * all items are finished. It remains stored too to allow back-and-forth
+   * switching between the "Show Original" and "Show Translation" functions.
+   *
+   * @param result    A string with the textual result received from the server,
+   *                  which can be plain-text or a serialized HTML doc.
+   */
+  parseResult: function(result) {
+    if (this.isSimpleRoot) {
+      this.translation = [result];
+      return;
+    }
+
+    let domParser = Cc["@mozilla.org/xmlextras/domparser;1"]
+                      .createInstance(Ci.nsIDOMParser);
+
+    let doc = domParser.parseFromString(result, "text/html");
+    parseResultNode(this, doc.body.firstChild);
+  },
+
+  /**
+   * This function finds a child TranslationItem
+   * with the given id.
+   * @param id        The id to look for, in the format "n#"
+   * @returns         A TranslationItem with the given id, or null if
+   *                  it was not found.
+   */
+  getChildById: function(id) {
+    let foundChild = null;
+    for (let child of item.children) {
+      if (("n" + child.id) == id) {
+        foundChild = child;
+        break;
+      }
+    }
+    return foundChild;
+  }
+};
+
+/**
+ * Helper function to parse a HTML doc result.
+ * How it works:
+ *
+ * An example result string is:
+ *
+ * <div id="n1">Hello <b id="n2">World</b> of Mozilla.</div>
+ *
+ * For an element node, we look at its id and find the corresponding
+ * TranslationItem that was associated with this node, and then we
+ * walk down it repeating the process.
+ *
+ * For text nodes we simply add it as a string.
+ */
+function parseResultNode(item, node) {
+  item.translation = [];
+  for (let child of node.childNodes) {
+    if (child.nodeType == TEXT_NODE) {
+      item.translation.push(child.nodeValue);
+    } else {
+      let translationItemChild = item.getChildById(child.id);
+
+      if (translationItemChild) {
+        item.translation.push(translationItemChild);
+        parseResultNode(translationItemChild, child);
+      }
+    }
   }
 }