Javascript in IE Mobile 6.0

Is Ajax support on Internet Explorer Mobile?

Actually, IE Mobile’s Ajax support dates back to Windows Mobile 2003.

javascript & AJAX 實做心得
1. 可用AJAX，但desktop IE的javascript Framework有很多function不適用，因此建議還是依需求開發。
  1. 針對AJAX部份我有根據官方範例寫了一個Ajax call function for Mobile IE
    
    http://blackbing.net/lab/mobile/mobileAjax.js
2. 基本的javascript幾乎都支援，getElementById, setTimeout, etc..
3. 只有button 有onclick事件，其他如DIV、SPAN上沒有這種event。
4. 請注意IE Mobile 沒有「onMouseOver」事件。
5. CSS支援度差，不支援定位(position, top, left)，且javascript存取css的方式也有限，必須反覆測試style的表現。
6. On Smartphone/PocketPC 2003 innerText and innerHTML Properties are only supported on div and span elements.
  
  On Windows Mobile 5 innerText and innerHTML Properties are supported on all elements.

開發AJAX應用程式的注意事項：
1. 使用者介面越簡單越好
2. 資料傳輸量越精簡越好(JSON)
3. DOM tree 越淺(shallow)越好
4. 若有大量資料要隱藏，請避免使用display:none，直接採用DOM操作方式remove掉。(保持頁面資料越精簡越好)
5. 盡可能不要讓使用者輸入data，改由select方式
6. Adding On-Demand Script

其他：
1. how to configure Internet Explorer Mobile to display script errors?
  
  To configure IE Mobile to display script error messages requires you to create a new registry entry.
  1. Open the device/emulator registry using the Remote Registry Editor or other Windows Mobile registry tool
  2. Navigate to the registry key HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
  3. Create a new DWORD entry for the key; name the new entry ShowScriptErrors and set the value to 1
  4. Soft-reset the device/emulator
    
    Once you complete these steps, IE Mobile will display error messages for any script errors that occur.
2. Enabling Cross-Domain Calls in Your Development Environment
  
  When working in your development environment, you can disable the security check that prevents the XMLHTTP object from making a cross-domain call. You do this by modifying the value of the appropriate registry entry using the following steps.
  1. Open the device/emulator registry using the Remote Registry Editor or other Windows Mobile registry tool
  2. Navigate to the registry key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\Internet Settings\Zones\3
  3. Change the value of the entry named 1406 to 0.
  4. Soft-reset the device/emulator
    
    Once you complete these steps, the XMLHTTP object can call into any domain without restriction.

參考資料：
1. Mobile Web Development
  
  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnanchor/html/anch_mobilewebdev.asp
2. Mobile DOM Reference Guide
  
  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mobilesdk5/html/mogrfdomreferenceguide.asp
3. Mobile CSS Support
  
  http://msdn.microsoft.com/library/default.asp?url=/library/en-us/mobilesdk5/html/mogrfdomreferenceguide.asp?frame=true
4. Windows Mobile Developers Wiki
  
  http://channel9.msdn.com/wiki/default.aspx/MobileDeveloper.HomePage