Post-it code

I have my daily dose of programming and adventure. Just like post-it note, here is my way to remember interesting snippets of algorithm or hipstamatic scenes that I chance during the day!

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For the Goldeneye lovers, yes I mean one of the greatest games in N64. Check this out!

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Mercedes Benz and anime... creative overload!

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If only this will make it to the cinema, go STAR WARS!

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Awesomeness in 3D, nuff said.

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For all the 007 in us.

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I really miss collecting and playing LEGO. Will strive to kickstart this childhood hobby of mine again.

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iOS: Duplicating targets in xCode

After doing iOS development for a year, the time has come to utilize the same source code and spawn multiple applications.

Although the answer is quite obvious to some, the execution is not as simple. Yes, we know the way to do so is bysimply right click the project target and select duplicate.

Does it end there? Nope.

2 Very important procedures to a proper target duplication ==========================================

1. In the duplicate target 'Info' tab, specify the intended bundle identifier. I.e. com.companyname.diffversionapp.

Explanation: Identifier is automatically referring to the default target. Building it will simple overwriting the original application.

2. In the duplicate target 'Build Settings' tab, locate Packaging and change the product name. I.e. Different Version App

Explanation: Upon duplication, you might find your duplicate target works fine but upon more duplication, xCode will not assist you to ensure the product name is different from the first duplicate. Build process will fail if prior to it, another application with the same product name has been built and run.

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MySql: Deleting duplicate row

I just discovered that due to a flaw in certain logic, my table has duplicate data. For illustration:

table_name | id | field_name | | 1  | 1 | | 2  | 1 | | 3  | 2 | | 4  | 3 | | 5  | 3 | By design, there should only be a single 1 and 3 in field_name. After a short search, the query below will delete the duplicates and keep a single unique data. Delete Duplicate Query ===================================== DELETE n1 FROM table_name n1, table_name n2 WHERE (n1.id > n2.id AND n1.field_name = n2.field_name) Thanks to the solution from the following post: http://stackoverflow.com/questions/4685173/delete-all-duplicate-rows-except-for-one-in-mysql

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Arc

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MySql: Querying data by month

I realize that it is a common mistake to query monthly data using GROUP BY MONTH(date). It might seem to work but if your date data span more than a single year, you would actually group new and old year data of the same month together.

To avoid such a circumstances, you could instead use YEAR_MONTH as it would return a unique month signature for the different year. Take a look at the query snippet below.

By Month Query =================

SELECT COUNT(*) FROM table GROUP BY EXTRACT(YEAR_MONTH FROM timestamp)

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HTTP Client App: Adding default header

Beats me, I was trying to run a simple POST request on my local server using HTTP Client - http://ditchnet.org/httpclient/ - to find out that I need to add default content type before it can work. Don't get me wrong, it is a great app for testing POST request, it was just me expecting things to be magical at times.

Default Content Type =====================

Header Name: Content-Type Header Value: application/x-www-form-urlencoded; charset=utf-8

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Tuckey: Configuring urlrewrite to simulate a different path

This might be a rare occassion, but to all of us who dabbles in running and maintaining our own web server, path changes is bound to happen.

Earlier this month, one of the application path that I have been running - As example: mydomain.com/not/cool/ is to be changed to mydomain.com/cool/. However, there are links distributed around the internet that have been referring to the old convention.

So I resorted to Tuckey (yes, I am running Tomcat as my web server) to ensure old references will not break.

In the case you need Tuckey: http://www.tuckey.org/urlrewrite/

Urlrewrite rule =======================

<rule> <from>^/not/cool/(.*)</from> <to>/cool/$1</to>  </rule> 

The above rule allows any query or path defined after mydomain.com/not/cool/ to be treated as coming from mydomain.com/cool/ without user noticing.

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Tomcat: Configuring multiple host names

We are often utilizing our Tomcat server to run multiple applications that resides on the same default root folder, namely webapps.

Also, most of us would like to have http://mydomain1.com/index and http://mydomain2.com/index to access different application path without much effort.

Fortunately, Tomcat allows configuration of host names that allows different host to access a specific application path. 

For example =======================

 Say we have an application in the folder: /tomcat/webapps/mywebsite

And we want http://mydomain.com to directly access the path mywebsite as root.

1. Go to tomcat folder, select conf and open server.xml 2. Within <Engine ..> tag, add the following:

<Host name="www.mydomain.com" appBase="webapps/mywebsite" unpackWARs="true" autoDeploy="true" xmlValidation="false" xmlNamespaceAware="false">  <Alias>mydomain.com</Alias> <Context path="" ...></Context> </Host> 

Alias tag is optional, but it allows you to specify multiple domain configurations to reach the same path as root.

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Mac OS X: Editing local hosts file

In the course of testing applications on local web server, there are often occurrences whereby you need custom host alias to point to specific application root. For example, instead of having localhost as the only working alias to 127.0.0.1, you might want to have mycustomhost as another alias referring to 127.0.0.1

Steps for editing local hosts file =============================

1. Open terminal

2. Go to the host file directory: cd /private/etc/

3. Open file editor: sudo vi hosts

4. Add new or update hosts:

- Press 'i' to start editing - Example of new host: myscustomhost - 127.0.0.1 - Save by pressing [shift]+[:], continue by writing 'wq!'

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iOS: (Tips) Creating MainWindow.xib in Xcode 4.2

There is always a new thing to discover when it comes to updating one's Xcode. So today I decided to create a new project based on Tab Bar Navigation to fool around and to my amazement, where is the ever important MainWindow.xib?

So I gave a read on Google and found out that MainWindow is not generated on the templates and instead the view controllers and its related component are generated programmatically in the AppDelegate.

Luckily, I found this wonderful blogpost!

Recreating MainWindow in project =========================

http://www.makebetterthings.com/iphone/where-is-mainwindow-xib-in-xcode-4-2/

Tested and worked like a charm, but as the above walkthrough makes use of an empty application template, do not forget to add the newly added view controller in the MainWindow as root at the didFinishLaunchingWithOptions.

self.window.rootViewController = self.[your new view controller here];

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iOS: Using background image on selected table cell

This might be something that lots of people know about already, but let me repeat them since today I happened to need a custom image to be used and shown when a cell is selected (clicked!).

Custom selected cell image ===========================

Assuming you are at cellForRowAtIndexPath delegate, apply the following:

cell.selectedBackgroundView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"selected_image.png"]] autorelease];

Note: If you are using custom cell with variable height, the image will be stretched to follow the cell height. So just be creative in designing the image to ensure it looks 'right' even when stretched.