nicotter: greasemonkey script for posting NicottoTown mutter to Twitter

nicotter.user.js

// ==UserScript==
// @name 			nicotter
// @version 		0.01
// @namespace 		http://www.nicotto.jp
// @description 	post NicottoTown mutter to Twitter
// @author 			uochan (or liquidz@GitHub)
// @include 		http://www.nicotto.jp/user/mypage*
// ==/UserScript==

(function(){
	// ========== YOU CAN EDIT ==========
	var flags = {
		// Twitterへの投稿確認の有無
		confirm_before_post: true,
		// Twitterへの投稿結果の表示・非表示
		alert_result: true
	};
	var messages = {
		question: "Twitterに投稿しますか？",
		post_success: "Twitterへ投稿しました。",
		post_error: "Twitterへの投稿に失敗しました。"
	};
	// ==================================

	// =foreach
	// ----------------------------------------------------
	var foreach = function(obj, fn){
		for(var i = 0; i < obj.length; ++i){
			if(fn(obj[i], i) == -1) break;
		}
	};

	// =findElementByAttribute
	// ----------------------------------------------------
	var findElementByAttribute = function(params){
		var result = null;
		if(params.tag && params.key && params.value){
			foreach(document.getElementsByTagName(params.tag), function(x){
				if(x.getAttribute(params.key).indexOf(params.value) != -1){
					result = x;
					return -1;  // foreachから抜ける(breakの代わり)
				}
			});
		}
		return result;
	}

	// =hookPostMessage
	// ----------------------------------------------------
	var hookPostMessage = function(hook_fn){
		var form = findElementByAttribute({tag: 'form', key: 'onsubmit', value: 'postMessage'});
		var a = findElementByAttribute({tag: 'a', key: 'href', value: 'postMessage()'});

		if(form) form.addEventListener("submit", hook_fn, false);
		if(a) a.addEventListener("click", hook_fn, false);
	};

	// =postToTwitter
	// ----------------------------------------------------
	var postToTwitter = function(status){
		GM_xmlhttpRequest({
			method: 'POST',
			url: 'http://twitter.com/statuses/update.json',
			data: 'status=' + encodeURIComponent(status),
			headers: {
				"Content-type": "application/x-www-form-urlencoded"
			},
			onload: function(res){
				if(flags.alert_result) alert(messages.post_success);
			},
			onerror: function(res){
				if(flags.alert_result) alert(messages.post_error);
			}
		});
	};

	// =main
	// ----------------------------------------------------
	hookPostMessage(function(){
		if(flags.confirm_before_post ? (confirm(messages.question) ? true : false) : true){
			var input_form = findElementByAttribute({tag: 'input', key: 'name', value: 'message'});
			if(input_form) postToTwitter(input_form.value);
		}
	});
})();