Crawler frontend

lib/client.js

+function get(url, callback)
+{
+  let request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+      .createInstance(Ci.nsIXMLHttpRequest);
+  request.mozBackgroundRequest = true;
+  request.open("GET", url);
+  if (callback)
+    request.addEventListener("load", callback.bind(undefined, request));
+  request.send();
+}
+
+function postFile(url, window, filePath, callback)
+{
+  let formData = new window.FormData;
+  formData.append("file", new window.File(filePath));

[Wladimir Palant, 2012/09/25 09:40:39]

As discussed on IRC: we can avoid using the window here. This requires modifying
buildtools/bootstrap.js.tmpl so that it gets File from the scope of a JavaScript
module and add it to the scope of our modules (similar to the way it is
currently done for atob). And FormData can be constructed via XPCOM the way
you've done it originally.

+
+  let request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
+      .createInstance(Ci.nsIXMLHttpRequest);
+  request.mozBackgroundRequest = true;
+  request.open("POST", url);
+  if (callback)
+    request.addEventListener("load", callback.bind(undefined, request));
+  request.send(formData);
+}
+
+let Client = exports.Client = {};
+
+Client.fetchCrawlableSites = function(backendUrl, callback)
+{
+  get(backendUrl + "/crawlableSites", function(request)
+  {
+    let sites = request.responseText.trim().split("\n");
+    callback(sites);
+  });
+};
+
+Client.sendCrawlerDataFile = function(backendUrl, window, dataFilePath, callback)
+{
+  postFile(backendUrl + "/crawlerData", window, dataFilePath, callback);
+};