Could someone post pointer for a Dropbox client ActionScript 3 library for Flex?

I found this http://code.google.com/p/dropbox-as3/ in GoogleCode, but it is kind of undocumented.

Recently, Adobe Labs released a new tool Adobe AIR Launchpad, which helps to quick-start new Flex project. James Ward prepared a small Launchpad video intro.

The application, is a 4 panel long wizard, requests various properties and finally saves a fresh Flex project, which comes along with various convenience methods.

Phase 1 :: e.g. Auto-updating and transparency

Phase 2 :: e.g. center on launch, network status change and local preferences

Phase 3 :: e.g. Display PDF and ‘Open with Default Application’

Phase 4 :: Finally, Launchpad saves the generated Flash Builder 4 project

PS: I still hate the name Flash Builder 4:  The product should be named FLEX Builder 4.

As me, many software developers learned the relations view of database management system: Identifiy entities, develope a database schema, normalize it and map it to a real DBMS system. That’s fine. And for many application this approach is just fine.

For other types of application, this approach tends to make development complicated.

Suppose, you need to create a note taking application. The app should be able to take notes. A note should have a title, a text body and an arbitrary number of optional fields, a use may use to add small snippets of text. Hm, an arbitrary number of fields, which you don’t know up front? How would you implement them in your favorite DB system?

Create a new table, which keeps each single optional field? Probably too inefficient.
Serialize optional fields and drop them into a single attribute of a table? Hm, complicated. How would you manage search operations?

Without pointing towards a relational solution, I’d propose to use a non-relational DBMS system. Especially a schema-free DBMS.

Schema-free solutions

A schema-free DBMS is one, which allows to store any kind of data of any structure. You don’t need to define your DBs tables and attributes up-front. Simply create new attributes of as soon as you need a new attribute.

Think of a schema-free DBMS as one, which manages key-value coded tuples [XCode users: Key-Value coding comes to mind].

In case you’d like to have a look, your first Google hit might point you to CouchDB, which meanwhile is a project of the Apache foundation. CouchDB is an Erlang-based solution. Thus you not only need to download and install CouchDB, but an Erlang runtime too.

Recently I stumbled upon MongoDB, which comes as a no-dependencies solution. Download it and start mongod, the MongoDB server. That’s it. Finally, you might wish to download and install a MongoDB driver for your preferred language.

Yet, MongoDB doesn’t come with an AS3 binding. To get access to MongoDB from within your Flex/Air app, various ways exist. One might use MongoDB’s PHP-driver, add some AMFPHP magic and finally expose your MongoDB’s API to flex.

Resources

A recorded webinar by MongoDB’s parents
A MongoDB presentation held at the NOSQL conference 06/2009

PS: Actually, it is kind of funny, how IBM developed SQL: The original intention was to create a tool for managers to easily retrieve data from DB systems – not a tool for developers.

Actually, not that harmful. But you should be aware of a special meaning of this Flex object property. Here’s the story:

Today, I tried to develop a method the create shallow and deep copies of objects. Finally, I prepared this method, initially without the line marked with __MARK__:

static private function clone( source:Object, deep:Boolean = false ):Object
  {
    if ( null == source ) {
    return null;
    }
    var copy:Object;
    if ( true == deep ) {
       copy =  ObjectUtil.copy( source );
    } else {
      copy = new Object();
      for( var key:Object in source ) {
        if (  ( 'mx_internal_uid' != key ) ) {     // __MARK__
          copy[ key ] = source[ key ];
        }
     }
  }
  return copy;
} // clone

Without the line marked by __MARK__, the method copies (more or less raw) objects, but the dataProvider-driven controls gets in trouble: List-based control add each managed object a ‘mx_internal_uid‘ to identify each data object. Thus, if you copy the ‘mx_internal_uid’ property, e.g. a DataGrid will no longer be able to distinguish the original source object or the clone(source) object.

Thus, it’s appropriate to not copy ‘mx_internal_uid‘ from source to clone.

Fine! You just managed to finish your first Flex-base AIR application. Using FlexBuilder’s Export Release Build…., you managed to package your deployable solution into a *.air file. Finally, you uploaded the *.air file to your web-server – and your coding mates tell you that not event a bit of an installation gets started. Too bad. What happened?

Most likely, you missed to assign the correct mime-type! Don’t forget, that you need to tell browsers, that files with *.air extensions actually are Adobe AIR installer files.

If you run Apache, adding the correct MIME type is simple:

AddType application/vnd.adobe.air-application-installer-package+zip .air

As always: Big trouble, small solution.Don’t forget, that this setting is absolutely vital! You need to set it – even if some browsers might be able to run the AIR install package with it. Most browser won’t…

Auditorium is a logic puzzle. Auditorium is a music omposition application. Auditorium is simple gorgeous:

If you play Auditorium, you place bricks on a board, which attract or deflect streams of particles.
If you move bricks around, Auditorium generates music, if the particle streams passes so called audio-containers.

Let the stream pass all audio-container you’ll get move to the next layer. Gorgeous!

Here’s a small helper class CPreferencesManager which manages application preferences by means of a key/value set, which I added as a comment to coldfusionjedi‘s nice blog:

Sample usecase: Make window positions persist after relaunch of an application:

1. Create an instance:

<tracker:CPreferencesManager    id=”thePrefs” />

2. Attach windowMove events to your Window:

windowMove=”thePrefs.setPreference(‘main.window.x’,
   this.nativeWindow.x.toString() );
   thePrefs.setPreference(‘main.window.y’, this.nativeWindow.y.toString() );”

3. After creationComplete, move the window to its position of the one but last launch:

var posX:int = int( thePrefs.getPreference(‘main.window.x’ ) );
var posY:int = int( thePrefs.getPreference(‘main.window.y’ ) );
move( posX, posY );      

The implementation:

package com.your.company
{
   import flash.filesystem.File;
   import flash.filesystem.FileMode;
   import flash.filesystem.FileStream;
   import flash.utils.ByteArray;
   import flash.utils.Dictionary;
   import flash.utils.IDataInput;
   import flash.utils.IDataOutput;
   import flash.utils.IExternalizable;
   
   import mx.controls.Alert;
   
   public class CPreferencesManager implements IExternalizable
   {
      
      private var _prefValues:Dictionary;
      private   var   _prefsStream:FileStream;
      
      public function CPreferencesManager()
      {

         _prefValues = new Dictionary();
         loadPreferences();
         
      }
      
      public function loadPreferences():void {
   
         var fp: File = File.applicationStorageDirectory;
         
         fp = fp.resolvePath( ‘prefs.xml’ );
         
         if ( fp.exists ) {
            
            _prefsStream = new FileStream();
            _prefsStream.open( fp, FileMode.READ);
            
            readExternal( _prefsStream );
            _prefsStream.close();
            
         } else {
            _prefValues[ 'appName' ] = ‘tracker’; // test-code
            savePreferences();
         }

      }
      
      public function savePreferences():void {

         var fp: File = File.applicationStorageDirectory;
         
         fp = fp.resolvePath( ‘prefs.xml’ );
         
         _prefsStream = new FileStream();
         _prefsStream.open( fp, FileMode.WRITE );
         
         writeExternal( _prefsStream );
         _prefsStream.close();
         
      }
      
      public function setPreference( name:String, value:Object ):void {
         
         _prefValues[ name ] = value;
         savePreferences();
         
      }

      public function getPreference( name:String ):Object {
         
         return _prefValues[ name ];
         
      }
      
      
      
      public function readExternal(input:IDataInput):void
    {
       
    var bytes:ByteArray = new ByteArray();
       input.readBytes( bytes, 0, input.bytesAvailable );

    var q:Object = bytes.readObject();
    
    _prefValues = new Dictionary();
    
    for( var p:Object in q ) {
       _prefValues[ p ] = q[p];
    }
    
    // Alert.show( _prefValues.toString() );
    
    }
   
      public function writeExternal(output:IDataOutput):void
    {

    var bytes:ByteArray = new ByteArray();
    bytes.writeObject( _prefValues );
    
    output.writeBytes( bytes );
    }

   }
}

Just a short note, that Parleys just published a new video Enterprise RIA with Flex and Java.

As a Flex coder, you might give this AIR-based viewer a try and explore Parleys right from your desktop. Visit this page to learn more about Parleys Flex/AIR offerings.

Much like Java, Flex compiles code into a bytecode representation for the Flash virtual machine (Flash VM). While opening VM code using a text editor, certain tools are able to retrieve significant portions of information for compiles Flex app. Much like obfuscators for JAVA, obfuscators for Flex/AS try to hide as much as possible in compiled code.

As always, you can’t obfuscate all. How much an obfuscator helps, depends on your needs and your project. Here is a (imcomplete) list of tools:

http://ambiera.com/irrfuscator/index.html [Free/BETA]
http://www.kindisoft.com/secureSWF/

Genable, another obfuscator, has been sold by the developer to another company, but you can still access a preview here:

http://web.archive.org/web/20040201231108/www.genable.com/aso/preview.html

Additionally, this video on InsideRIA presents NitroLM, a pro-class SWF encryptor. Take note, that NitroLM provides more than just encryption, since it is a complete license managemet solution.

In case you want to add custom menu items to the default menu item of a Flex app, here is a small snippet to get you started:

Step one – Minimize the default contextual menu

// defaultMenu will keep our reference to the default menu of our browser-based
// Flex application
var defaultMenu:ContextMenu;

// Now, let's make the default menu as small as possible
defaultMenu = Application.application.contextMenu;
defaultMenu.hideBuiltInItems();

Step two – Add you own menu entry to the contextual menu

Then, let’t create a new menu item to be added to the default contextual menu.

// item is our new menu item
var item:ContextMenuItem = new ContextMenuItem("Some String");

// Add an event listener, which gets fired, if the user selected the menu item
item.addEventListener(ContextMenuEvent.MENU_ITEM_SELECT,handleStaticMenuItem);

// Finally, it's time to add the new menu item to the default menu
defaultMenu.customItems.push( item );

// Implement your own event handling routine here
public function handleStaticMenuItem( anEvent:Event ):void {

}

While it’s very simple to add a new menu entry, you can’t get rid of all Flash Player contextual menu entries: Even if you call hideBuildInMenu(), certain menu items will still be visible.

Once you deploy your Flex application as a standalone AIR application, you are free again, since AIR application don’t have default menu items.