Content Scope Runner

An extension of the Content Script Injection technique, this snippet automatically runs the entire user script in the content scope.

if(typeof __PAGE_SCOPE_RUN__ == 'undefined') {
   (function page_scope_runner() {
      // Grab the anonymous function the entire script is wrapped in
      var my_src = page_scope_runner.caller.toString();
      
      // Alter the script's environment to prevent unbounded recursion...
      var safe_source = "var __PAGE_SCOPE_RUN__ = 'yes';\n";
      // ...and then allow it to call our anonymous function.
      safeSource += "(" + my_src + ")();\n";

      // Create a script node holding this script, plus a marker that lets us
      // know we are running in the page scope (not the Greasemonkey sandbox).
      var script = document.createElement('script');
      script.setAttribute("type", "application/javascript");
      script.appendChild(document.createTextNode(safe_src));

      // Insert the script node into the page, so it will run, and immediately
      // remove it to clean up.
      document.documentElement.appendChild(script);
      document.documentElement.removeChild(script);
   })();
   return;
}

As long as this is the first piece of code in your script, it will stop execution of the remainder of the script, and re-start execution completely within the content scope. Thus you need not worry about any of the security restrictions from XPCNativeWrappers in the Greasemonkey sandbox. You also will, of course, not have access to any of the APIs.