Sencha Touch 2.0在OO的包裝上做的還算不錯, 把MVC的角色切分的還蠻清楚的, 以List為例, 大概就像這樣:
但如果是要用Facebook Java script SDK去存取Facebook Graph API這類, 似乎就不知道怎歸類了, 如果直接用JSONP去存取Graph API, 則碰到Authentication error.. orz
那…就只好寫一個Proxy了, 像這樣:
https://gist.github.com/1341345.js?file=gistfile1
以下是一個使用這範例存取使用者自己的Facebook Group的範例:
上次寫了一篇"startActivityForResult and callback in WebView“, 本篇則是上次這篇的延伸應用, 這是有人問我如何inject一整個javascript file到一個web page內(剛剛回顧了一下自己這篇, 發現我把它叫做javascript injection)
其實原理是一樣的, 在載入完原本的web page之後, 一樣透過URL來插入script:
mWebView.loadUrl("javascript:var js = document.createElement(‘script’);js.type = 'text/javascript’;js.src = ’http://my_host/1.js’;document.getElementsByTagName('head’)[0].appendChild(js);”);
一樣是透過“javascript:”來inject, 不一樣的只是, 這次我要插入的是一整個js檔, 所以這串javascript的目的就是要建立一個新的script element, 並將它插入head裡, 這樣任務就達成了
但這方法的缺點是, 來源必須是一個url, 也就是要把script file放在server才可以, 如果script是來自應用程式本身, 比如說放在應用程式apk裡面, 或是放在data partition就不行了
在Honeycomb之前的版本, 我還沒想到一個比較好的解法, 但Honeycomb (API level 11, 含11)之後就有一個比較簡單的解法了
作法就是overwrite WebViewClient的shouldInterceptRequest,這似乎就是為了類似的用途而生的呀~~
這邊我將來自於apk asset目錄裡的檔案的url定義成"asset://“, 因此, 想當然耳, 要導向的url就是這種, 作法也很簡單, 將asset的input stream包裝成WebResourceResponse就可以了, 這樣只要"js.src="後面的url是"asset://xxx.js”, 這js的來源就是apk裡的asset
缺點是, 這方法只適用API level 11之後
延伸應用? 其實應該可以利用這個API做出一個lightweight版本的client side serlvet (這樣叫好像也不是很貼切, 反正就是不需要透過http去存取), 不過因為資訊只有url可以使用, 因此不能implement “POST”…
題外話, 這個我是在Ice cream sandwich的emulator上測試的, 不過真的要小抱怨一下, 開個emulator要開很久, 看篇漫畫結束後還沒跑完, 如果叫developer完全用emulator開發, 真的會抓狂吧….這樣開發者的開發意願也會降低吧…. = =“
Android 4.0 Ice Cream Sandwich 有一個新功能是, 使用者可以停用(Disable)系統上預載的應用程式, 以往系統預載的應用程式是不能被刪除的, 現在, 新的版本多了一個按鈕讓你可以停用它:
這是中國人所謂的…“眼不見為淨"嗎?
被Disable掉的應用程式基本上並沒被移除, 它還是在你手機裡面, 並不會因此多出一些可使用空間, 只是你看他不爽, 以後就可以不用再看到他了….(呃, 不爽用就不要用不就好了)
這是新功能嗎? 對這介面上來說…這按鈕…是新的
PackageManager裡面有個叫做setApplicationEnabledSetting , 這用途就是用來作這種事的, 所以做這樣一個功能到底多複雜呢?
PackageManager pm = getPackageManager(); pm.setApplicationEnabledSetting("com.geekyouup.paug.awesomepager”, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, 0);
就差不多上面那樣
當然啦, 是沒辦法隨便寫一個軟體去disable人家的應用程式的, 如果可以, 不就天下大亂了, 這API只能用在跟你的應用程式相同的uid的package
不過對於系統應用程式來說, 就沒這限制了吧
至於這API啥時有的? Since API level “1”
Ok, So…..
We got a new feature……….
JQuery mobile跟Sencha touch都是蠻完整的mobile web framework, 兩者各有擅長, 比較起來以開發的角度我比較喜歡JQuery所標榜的"Write less, Do more"的哲學下的架構, 而不喜歡Sencha touch把一堆html寫到code裡面去, 但Sencha touch又有比較好的UI look and feel
以tab panel為例,
Sencha touch:
這兩個作法大異其趣
Sencha 的HTML 內容
裡面除了script以外根本就是空的, UI的創建放在app.js(以這範例而言)裡如下:
https://gist.github.com/1301828.js?file=gistfile1
Tabs的內容在哪? items裡分別就是兩個tab, html直接以字串的形態寫在裡面, 老實說, 我覺得這很醜, 也容易出問題, 如果頁面的內容是相當複雜的, 這樣並不是很好
再看看jQuery Mobile的作法:
這份source code有點偷懶, 剪剪貼貼過來的, 不過其實就這麼一個html, 並不需要寫額外的javascript code, 乾淨多了
如果也可以用類似的寫法寫Sencha touch的UI似乎應該會比較好一點, 像是這樣寫:
做了個實驗, 剛寫下這段code把上面那段轉成跟第一個範例一樣的畫面:
https://gist.github.com/1301855.js?file=gistfile1
看來如果再多層包裝其實也不用醜醜的通通把UI hard code到js codes裡面去
Looks familiar? It’s not Google+. It’s DIASPORA. An open source project that implements a distributed social networking service. This project was announced on APRIL 24, 2010 (Just right after Facebook f8 2010 that is at APRIL 21). Alpha version was released at NOV 23, 2010 (two days before my birthday :P).
According to this, Mark Zuckerbug also donated to it just because it’s a cool idea.
It’s built on Ruby on rails. So it might be not so difficult to port it to Heroku platform which is a nice RoR host (althrough it still took me some time). It might be easier than build from scratch on a Linux.
I’m a newbie to these two (Heroku and DIASPORA). I’m also not familar with RoR. Here records steps I tried.
create an application on heroku
First, you need to create an application on Heroku. There are several platform stack on Heroku. Cedar stack might be the newest and most powerful one. It supports several languages and frameworks. And It also makes it very easy to deploy RoR applications.
You need to install heroku CLI before creating an application. And use “heroku login” to login to your heroku account.
Run the following command to create a new cedar application (assume application name is “mysocialy”) –
heroku create –stack cedar mysocialy
After the application created, you’ll have a url “http://mysocialy.herokuapp.com/” for your site. And a git repository: [email protected]:mysocialy.git
import source codes
Get DIASPORA* source codes from git hub:
git clone git://github.com/diaspora/diaspora.git
Get your source codes from Heroku git repository (you’ll get an empty folder):
git clone [email protected]:mysocialy.git
If you have trouble to download from Heroku. Try to use “heroku keys:add” to add your ssh public key and try again.
Copy all files except “.git” folder from “diaspora” to “mysocialy”.
Initial configuration
Make new configuration files from example.
cd config
mv application.yml.example application.yml
mv database.yml.example database.yml
Edit application.yml. Make “pod_url” to your host. In this case:
pod_url: “http://mysocialy.herokuapp.com/”
Deploy codes
Add and commit files:
git add .
git commit -am ‘initial import’
Push them to Heroku
git push origin master
The coolest thing that Heroku does is that it makes deploy codes so easy. All you need to do is to push your codes to its git repository. And it could also install all related modules for you (that is configured in Gemfile). Super easy.
Ok, I must admit that I lie a little bit. There might be some problems. After I pushes all codes to Heroku, I found there is an error that it couldn’t find 'pg’ (postgresSQL). Looks like it does not install into gem.
I found the answer that it might be problem with gem version. Need to run “bundle install” at local. This will generate a new Gemfile.lock. Push this new file to Heroku might solve this problem
Ok, that’s all?
Not sure if I missed anything (I might). Anyway, what I did is alive at “http://mysocialy.herokuapp.com/”.
