Bug 556361 - New searches from the searchbar don't get synced [r=mconnor]

Add a component that notifies when satchel methods are getting called. The notifications come as "form-notifier" with JSON data of the function name, arguments, and type (before vs after).

services/sync/FormNotifier.js

@@ -0,0 +1,51 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+function FormNotifier() {
+  let baseForm = Components.classesByID["{a2059c0e-5a58-4c55-ab7c-26f0557546ef}"].
+    getService(Ci.nsIFormHistory2)
+  let obs = Cc["@mozilla.org/observer-service;1"].
+    getService(Ci.nsIObserverService);
+
+  for (let keyval in Iterator(baseForm)) {
+    // Make a local copy of these values
+    let [key, val] = keyval;
+
+    // Don't overwrite something we already have
+    if (key in this)
+      continue;
+
+    // Make a getter to grab non-functions
+    if (typeof val != "function") {
+      this.__defineGetter__(key, function() baseForm[key]);
+      continue;
+    }
+
+    // Wrap the function with notifications
+    this[key] = function() {
+      let args = Array.slice(arguments);
+      let notify = function(type) {
+        obs.notifyObservers(null, "form-notifier", JSON.stringify({
+          args: args,
+          func: key,
+          type: type
+        }));
+      };
+
+      notify("before");
+      val.apply(this, arguments);
+      notify("after");
+    };
+  }
+}
+FormNotifier.prototype = {
+  classDescription: "Form Notifier Wrapper",
+  contractID: "@mozilla.org/satchel/form-history;1",
+  classID: Components.ID("{be5a097b-6ee6-4c6a-8eca-6bce87d570e9}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIFormHistory2]),
+};
+
+let components = [FormNotifier];
+function NSGetModule(compMgr, fileSpec) XPCOMUtils.generateModule(components);

services/sync/modules/engines/forms.js

@@ -197,14 +197,39 @@ FormStore.prototype = {
 
 function FormTracker(name) {
   Tracker.call(this, name);
+  Svc.Obs.add("form-notifier", this);
   Svc.Observer.addObserver(this, "earlyformsubmit", false);
 }
 FormTracker.prototype = {
   __proto__: Tracker.prototype,
 
-  QueryInterface: XPCOMUtils.generateQI([Ci.nsIFormSubmitObserver]),
+  QueryInterface: XPCOMUtils.generateQI([
+    Ci.nsIFormSubmitObserver,
+    Ci.nsIObserver]),
+
+  trackEntry: function trackEntry(name, value) {
+    this.addChangedID(Utils.sha1(name + value));
+    this.score += 10;
+  },
+
+  observe: function observe(subject, topic, data) {
+    let name, value;
+
+    // Figure out if it's a function that we care about tracking
+    let formCall = JSON.parse(data);
+    let func = formCall.func;
+    if ((func == "addEntry" && formCall.type == "after") ||
+        (func == "removeEntry" && formCall.type == "before"))
+      [name, value] = formCall.args;
+
+    // Skip if there's nothing of interest
+    if (name == null || value == null)
+      return;
+
+    this._log.trace("Logging form action: " + [func, name, value]);
+    this.trackEntry(name, value);
+  },
 
-  /* 10 points per form element */
   notify: function FormTracker_notify(formElement, aWindow, actionURI) {
     if (this.ignoreAll)
       return;
@@ -268,8 +293,7 @@ FormTracker.prototype = {
       }
 
       this._log.trace("Logging form element: " + name + " :: " + el.value);
-      this.addChangedID(Utils.sha1(name + el.value));
-      this.score += 10;
+      this.trackEntry(name, el.value);
     }
   }
 };