Crawler, second version

lib/command_line.js

+/*
+ * A bootstrapped extension must load its own command-line handler, because it won't load from chrome.manifest. See
+ * https://developer.mozilla.org/en-US/docs/Chrome_Registration and its section "Instructions supported in bootstrapped
+ * add-ons". This is only barely mentioned in
+ * https://developer.mozilla.org/en-US/docs/Extensions/Bootstrapped_extensions, and only in passing at that. The upshot
+ * is that you have to replicate what would otherwise happen in chrome.manifest.
+ *
+ * A command line handler must implement the interface nsICommandLineHandler and, in order to hook into the command line
+ * system, must register itself in the category "command-line-handler".  See
+ * https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsICommandLineHandler
+ * The value of the category entry is a service contract ID, which is used to construct an instance of the handler.
+ *
+ * The way to construct an instance given a contract ID is to implement nsIFactory and, in order that hook into the
+ * instantiation system, must register itself with the component registrar. The component registrar is also the
+ * component manager, but through the interface nsIComponentRegistrar, which is not the default interface.
+ */
+
+Cu.import( "resource://gre/modules/XPCOMUtils.jsm" );
+
+let { Bootstrap_XPCOM } = require( "bootstrap_xpcom" );
+
+//-----------------------------------------------------------------------------------------
+// Command_Line
+//-----------------------------------------------------------------------------------------
+
+/**
+ * The command line handler singleton.
+ *
+ * This object supplies its own factory to XPCOM, so there's no need for a constructor function; instead, the factory
+ * function simply returns 'this' (essentially, though it passes it through QueryInterface first).
+ */
+var Command_Line = new Bootstrap_XPCOM.Singleton_class(
+  "ABP Crawler - Command Line Handler",
+  Components.ID( "{771575E6-62FE-48CB-BC24-EAEFDDC1CA1D}" ),
+  "@adblockplus.org/abpcrawler/command-line;1",
+  [ Ci.nsICommandLineHandler ],
+  [
+    {
+      category: "command-line-handler",
+      // The entry starts with "k" so that it has slightly higher priority than ordinary command line handlers.
+      entry: "k-abpcrawler"
+    }
+  ] );
+
+Command_Line.helpInfo = "" +
+  // -    -    -    -    -    -    -    -     -    -    -    -    -    -  | wrap here
+  "AdBlock Plus Crawler\n" +
+  "  -abpcrawler           Start a crawl. Must specify both an input and\n" +
+  "                        an output.\n" +
+  "  -input_file <path>    Use <path> as input file from which to compile\n" +
+  "                        instructions for the crawl.\n" +
+  "  -output_dir <path>    Use <path> as output directory to contain a\n" +
+  "                        file of crawl results.\n" +
+  "  -output_base <name>   Use <name> as the base name for a file of crawl\n" +
+  "                        results. Optional. Default='crawl_results'.\n" +
+  "  -max_tabs <N>         Maximum number of tabs for simultananeous\n" +
+  "                        loading of target sites.\n";
+
+/**
+ * Set a startup hook to run
+ * @param f
+ */
+Command_Line.set_startup_hook = function( f )
+{
+  this._startup_hook = f;
+};
+
+/**
+ * The actual handler.
+ *
+ * @param {nsICommandLine} ff_command_line
+ *    The Firefox command line
+ */
+Command_Line.handle = function( ff_command_line )
+{
+  dump( "Command line handler: abpcrawler\n" );
+
+  if ( !ff_command_line.handleFlag( "abpcrawler", false ) )
+  {
+    /*
+     * There's no '--abpcrawler' option on the command line. As a result we don't try to interpret any other
+     * command line flags.
+     */
+    return;
+  }
+  var flags = this.flags = { abpcrawler: true };
+  /*
+   * The '--abpcrawler' argument indicates that this invocation is designated as a crawl session. As a result,
+   * we don't perform the default action, which is opening the start page in the browser for interactive use.
+   */
+  ff_command_line.preventDefault = true;
+
+  let x = ff_command_line.handleFlagWithParam( "input_file", false );
+  if ( x ) flags.input_file = x;
+  x = ff_command_line.handleFlagWithParam( "output_dir", false );
+  if ( x ) flags.output_dir = x;
+  x = ff_command_line.handleFlagWithParam( "output_base", false );
+  if ( x ) flags.output_base = x;
+  x = ff_command_line.handleFlagWithParam( "max_tabs", false );
+  if ( x ) flags.max_tabs = x;
+
+  /*
+   * Some experimentation revealed that this command line handler runs _after_ observer notifications for topic
+   * 'final-ui-startup'. (This seems like a design failure, since it ought to happen after the add-on has an opportunity
+   * to initialize itself at 'profile-after-change' but before anything else. Whatever.) As a result, we call a startup
+   * hook here.
+   */
+  if ( this._startup_hook )
+  {
+    try
+    {
+      this._startup_hook();
+    }
+    catch ( e )
+    {
+      dump( "Command_Line/handle/startup hook: Unexpected exception"
+        + (("message" in e) ? ": " + e.message : "") + ".\n" );
+    }
+  }
+};
+
+exports.Command_Line = Command_Line;
+try
+{
+  /*
+   * We must call init() after handle() is defined, so that if the category manager triggers an immediate event
+   * that we have already initialized fully.
+   */
+  Command_Line.init();
+}
+catch ( e )
+{
+  dump( "command_line.js: Unexpected exception during init(): " + e.message );
+}