Language Evaluate Protocol

gistfile1.js

Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");

var Ci = Components.interfaces;
var Cc = Components.classes;

var Language = {
	evaluators: {
		"jscript": "cscript //E:JScript //Nologo",
		"vbs"    : "cscript //E:VBScript //Nologo",
		"ruby"   : "ruby",
		"perl"   : "perl",
	},

	evaluate: function(command, code){
		var process = Cc["@mozilla.org/process/util;1"].createInstance(Ci.nsIProcess);

		var bat    = new TempFile("eval", "bat");
		var script = new TempFile("eval", "code");
		var out    = new TempFile("eval", "out");

		script.write(code);

		code.length? bat.write([command, script.file.path, ">", out.file.path].join(" "))
			       : bat.write([command, ">", out.file.path].join(" "));

		process.init(bat.file);
		process.run(true, [], 0);

		var res = out.read();

		bat.remove(false);
		out.remove(false);

		if(script.exists)
			script.remove(false);

		return res;
	}
};

function Protocol(){}

Protocol.prototype = {
	classDescription: "Language Evaluate Protocol",
	classID         : Components.ID("F32C80B3-404B-4ce0-8590-B9DC25BDFA9A"),
	contractID      : "@mozilla.org/network/protocol;1?name=eval",
	QueryInterface  : XPCOMUtils.generateQI([Ci.nsIProtocolHandler]),


	scheme       : "eval",
	defaultPort  : -1,
	protocolFlags: Ci.nsIProtocolHandler.URI_NORELATIVE
	             | Ci.nsIProtocolHandler.URI_NOAUTH
	             | Ci.nsIProtocolHandler.URI_DANGEROUS_TO_LOAD,


	allowPort: function(port, scheme){
		return false;
	},

	newURI: function(spec, charset, baseURI){
		var uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
		uri.spec = spec;
		return uri;
	},

	newChannel: function(aURI){
		var ios   = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
		var comps = (new RegExp("^" + this.scheme + ":([^;]+);?(.*)$")).exec(aURI.spec);
		var lang  = decodeURIComponent(comps[1]);
		var code  = decodeURIComponent(comps[2]);
		var evalu = Language.evaluators[lang] || lang;
		var res   = Language.evaluate(evalu, code);

		log(res);

		return ios.newChannel("data:text/plain;base64," + btoa(res) + "')", null, null);
	}

}

function NSGetModule(compMgr, fileSpec){
	return XPCOMUtils.generateModule([Protocol]);
}

/// util
function log(msg){
	var win = Cc['@mozilla.org/appshell/window-mediator;1']
		.getService(Ci.nsIWindowMediator)
		.getMostRecentWindow('navigator:browser');

	if(win.FirebugConsole && win.FirebugContext){
		var console = new win.FirebugConsole(win.FirebugContext, win.content);
		console["log"].apply(console, arguments);
		return true;
	}

	if(win.Firebug && win.Firebug.Console){
		win.Firebug.Console.logFormatted.call(win.Firebug.Console, Array.slice(arguments), win.FirebugContext, "log");
		return true;
	}

	Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).logStringMessage('' + msg);;
}

function TempFile(name, ext){
	var file = Cc["@mozilla.org/file/directory_service;1"].getService(Ci.nsIProperties).get("TmpD", Ci.nsIFile);
	file.append([name, (new Date()).getTime(), "tmp", ext].join("."));
	this.file = file;
}

TempFile.prototype = {
	read: function(){
		var istream = Cc["@mozilla.org/network/file-input-stream;1"] .createInstance(Ci.nsIFileInputStream);
		istream.init(this.file, 0x01, 0444, 0);
		istream.QueryInterface(Ci.nsILineInputStream);

		var line = {}, lines = [], hasmore;

		do{
			hasmore = istream.readLine(line);
			lines.push(line.value);
		} while(hasmore);

		istream.close();

		return lines.join("\n");
	},

	write: function(data){
		if(!data.length)
			return false;

		var foStream = Cc["@mozilla.org/network/file-output-stream;1"].createInstance(Ci.nsIFileOutputStream);
		foStream.init(this.file, 0x02 | 0x08 | 0x20, 0664, -1);
		foStream.write(data, data.length);
		foStream.close();
	},

	remove: function(){
		this.file.remove(false);
		this.file = null;
	}
};