Private Cloud System

Thinking of building my own cloud storage solution.

For a cloud storage system, usually there are two kinds of clients:
1. Complete sync. All data are seamlessly synced between the server and client.
2. Sync on demand. Only files/data to be used are downloaded and updated for the user. This usually happens on mobile devices where the storage size is small.

For a server, it would be good if there are some features in it:
1. revision history. You can trace back the data.
2. version control. This is common for multiple users. A problem occurs when two users check in the same file with their own modification. The system should be able to identify the check-out time.

Some people have posted their solutions:
rsync: http://fak3r.com/geek/howto-build-your-own-open-source-dropbox-clone/

sparkleshare: This seems a promising open source solution. http://sparkleshare.org/
some more: http://thefinalcastle.com/tag/virtual-private-server

Some backup solutions:
http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp

--

Update:

There are some solutions that are already in market and are nearly free:

1. http://www.tonido.com/

2. http://www.pogoplug.com/

Update 2:

1. Use plugapps for these devices

2. 破解 pogoplug:

http://www.beimeicn.com/Space/u=3M/m=blog/p=347411/s=nature_green/lang=schinese.html

三步驟讓 Google 只搜尋網路書籤連結內容

How to do

1. 將網路書籤 RSS Feed 輸入到下面第一欄位。
   
   譬如我的 Delicious 網址 http://feeds.delicious.com/v2/rss/migi?count=999 (記得把 count 改大一點


2. 將產生的文字複製到這個連結第一欄 XML specification URL，接著點 Refresh


3. 在下面 "Try searching for" 隨便輸入，接著點後面的 Search

這時就可以儘量搜尋了，試著搜尋最近加入的文章內容。也可以把這個網頁Bookmark起來，以後直接開來使用

RSS網址:

覺得太簡單沒什麼功能可以調整嗎？這裡有更複雜完整版

Language Auto Detector works with lang attribute自動語言選擇--現在直接使用 lang="zh" 即可

This is English in <span lang="en">
這是<span lang="zh">下看到的中文

---

Using this format is much easier than using the class attribute when posting articles.
PS. Note that the post title can also include span tag!! It changes as you change the language setting!!

這樣撰寫文章還是比較方便。原理是由 javascripti 搜索 span 及 div tag，再增加對應語言的 className。也就是說，就方法 class="lang_zh" 還是有效。

要注意的是為了不要讓瀏覽器 loading 太重，搜尋tag只含 div 和 span，也就是說，如果要在其他tag內有語言自動選擇功能，還是要乖乖寫 class="lang_zh"...不過這狀況總是沒有使用 span 的來得多。
PS. 連標題都可以寫span tag!! bogger真是太寬鬆了!

code:

 // for IE6 or before: change <span lang="en"> to <span class="lang_en">
 modList = document.getElementsByTagName("span");
 for (var i=0; i<modList.length; i+=1) {lang2class(modList[i]);}
 modList = document.getElementsByTagName("div");
 for (var i=0; i<modList.length; i+=1) {lang2class(modList[i]);}


function lang2class(elm)
{
 if (attr=elm.getAttribute("lang")) {elm.className+=" lang_"+attr;}
}

中英對照測試 (請使用上方下拉表單)

From: 自由電子報-國際新聞
Music fans turn up volume of legal downloads:study 研究：樂迷合法下載量增多

◎ 鄭寺音

Music fans worldwide downloaded 420 million songs legally over the Internet in 2005, a 20-fold increase from two years ago, research showed.

研究指出，全球音樂迷2005年在網路上合法下載4億2千萬首歌曲，兩年來增加了20倍。

Record labels reaped a 1.1-billion-dollar harvest from digital downloads, up from 380 million dollars the previous year, with about 40 percent of this revenue earned from music for mobile phones.

唱片業者從數位下載獲得11億美元的收益，前一年則有3億8千萬美元，這項收益約4成是從手機音樂賺來的。

...

---

Content:

<span lang="en">Music fans turn up volume of legal downloads:study</span&tt;<span lang="zh"> 研究：樂迷合法下載量增多</span>

◎ 鄭寺音
<div lang="en">
Music fans worldwide downloaded 420 million songs legally over the Internet in 2005, a 20-fold increase from two years ago, research showed.
</div><div lang="zh">
研究指出，全球音樂迷2005年在網路上合法下載4億2千萬首歌曲，兩年來增加了20倍。
</div><div lang="en">
Record labels reaped a 1.1-billion-dollar harvest from digital downloads, up from 380 million dollars the previous year, with about 40 percent of this revenue earned from music for mobile phones.
</div><div lang="zh">
唱片業者從數位下載獲得11億美元的收益，前一年則有3億8千萬美元，這項收益約4成是從手機音樂賺來的。
</div>

!! Simplest Automatic Javascript+CSS Multilingual Selector!!(號外)最簡單的 Javascript+CSS 網站語言自動選擇器

---

測試：Test:

This is English

這是中文

---

讓頁面自動選擇browser預設語言，一直是非英語主流部落客要將網站改成雙語環境最重要的功能
標題已經下英文了(我現在英文想得比中文快)，當然這篇文章之後也要變成提供雙語

It has always been needed for a multi-lingual blogger to build a site with automatic language selector. Now I have devised a very good way (I believe):

我的目標是 My Aim

blog只要寫一遍，中英文都放在同一篇文章中
但是post出去後，瀏覽器會自動選擇語言
此外，利用cookie做到讓使用者可以選擇希望看到的語言，甚至讓所有語言都呈現出來

We want to write blog once and only once. We want to put all languages into the same post, so it's easy to write/update.
Besdies, auto selection, we also want to select language manually.

原理 How To Do

1. 在文件中使用不同class 的tag包住不同語言:

1. Use tags with different class names to distinguish language.

<div class="lang_en">
This is English
</div>
<div class="lang_zh">
這是中文
</div>

2. 利用 CSS 之 display:none 來隱藏其中一種或多種語言。
Javascript可以讀取browser語言設定: browser.language (FF) / browser.browserLanguage(IE)

定義CSS如下：

2. Then, make use of CSS's display:none to hide text without the language we choose. Javascript can get the browser's language setting: browser.language (FF) / browser.browserLanguage(IE)

The language-selecting CSS:

.lang_zh_off .lang_zh
{ display:none; }

.lang_en_off .lang_en
{ display:none; }

如何利用Javascript修改CSS？最簡單的方法就是修改body(或其他大範圍tag)使其擁有不同className。

But how to modify CSS settings by Javascript? The simplest way it to modify the class name of large-range tag like body.



譬如若要讓body下只顯示中文，那就修改<body class="lang_en_off">
若要兩個都消失，則為 <body class="lang_en_off lang_zh_off">
為什麼要指定消失，而不指定顯示的語言？　因為如果要指定顯示，則必須先預設所有語言文字消失。一旦程式出錯，則整篇文章都沒有了。所以先使預設為全顯示，比較安全。

If we want to show jsut English in body, then change the body tag as:<body class="lang_en_off">. It can be done by Javascript. If we wnat to hide two languages: <body class="lang_en_off lang_zh_off">

A note for the reason why I define the trigger for "off" but not "on": If we let everything "off" but only display some languages triggered by "on", once a program error occurs, no trigger is set. Then nothing will display. We would rather display all text once the program does not work.



注意：class比id好用，因為一個tag可以很容易利用空白分隔，使其包含不同className

PS.
原想利用 <div lang="en"> 這種正規方式來指定語言，但因 IE6 不支援 CSS attribute selector而作罷 (*[lang="en"])

3. 再來重頭戲便是javascript:

3. The most important, the javascript code:

function __set_lang()
{
 /*
 //simple test:
 alert (document.body.className);
 document.body.className= "lang_zh_off lang_en_off";
 
 alert (document.body.className);
 return;
 */
 /*
 detectList['zh']='zh';
 detectList['en']='en';
 detectList['default'] ='en';
 */
 
 // detect browser default language
 var langCode = navigator.language || navigator.browserLanguage;
 var lang = langCode.toLowerCase();

 // detect language
 var attr="",found=false;
 lang = trim(lang).substr(0,2);

 if (lang!="zh") attr+=" lang_zh_off"; else found=true;
 //default:en
 if (found) attr+=" lang_en_off";
 
 // write body class
 var body_attr = body_original_attr;
 if (body_attr==null) body_attr="";
 document.body.className= body_attr+attr;
 
// alert ("done:"+document.body.className);
} 
function trim(str)
{
 return str.replace(/^\s+/, "").replace(/\s+$/, ""); 
}

利用 .className 修改及讀取body的class屬性。
(原本我用 setAttribute('class',...), 在IE6下竟發現這樣改不能讓CSS正確判斷修改過的class屬性!)



4.最後是把javascript 加到HTML中:

4. Finally, here's the HTML sample code:

<pre>
<body>
<script language="javascript" src="lang.js"></script>
...

這個部份的javascript 一定要加在body之後! (若要使用新版可以直接使用 lang attribute的code, 必須加到HTML最下面</body>附近!!)
另一種方法是修改 body 為 body onload="__set_lang()"

Be aware that this code must be added in the last line before </body> Another way is to modify body tag as: body onload="__set_lang()"



5. 此外cookie和下拉式表單比較簡單 請自行發揮, 或參考我包好的:

5. In addition, we can use cookie to store user preferred language. Display a drop-down list on the page. It is easier and I skip the details. See my packed codes here:

http://www-scf.usc.edu/~chunming/lang.css
http://www-scf.usc.edu/~chunming/lang.js


此blog 和我的首頁就是用這兩個檔案

This site and my personal website are examples that uses the two files above.