Manual Configuration, and existing instances

[drscn]

Hi,

I'm trying to configure Spring ActionScript manually (ie, without XML), but having some trouble getting existing instances into an ObjectFactory. More specifically, I'm trying to write an adapter so that I can use Spring with my current framework, and am struggling with the bindValue part. This is what I've got going so far. Any advice would be greatly appreciated.

package net.boyblack.robotlegs.adapters
{
	import net.boyblack.robotlegs.core.IInjector;

	import org.as3commons.reflect.ClassUtils;
	import org.as3commons.reflect.Field;
	import org.as3commons.reflect.MetaData;
	import org.as3commons.reflect.Type;
	import org.springextensions.actionscript.ioc.ObjectDefinition;
	import org.springextensions.actionscript.ioc.factory.support.DefaultListableObjectFactory;
	import org.springextensions.actionscript.utils.ObjectUtils;

	public class SpringInjector implements IInjector
	{
		protected var factory:DefaultListableObjectFactory;

		public function SpringInjector()
		{
			factory = new DefaultListableObjectFactory();
		}

		public function bindValue( whenAskedFor:Class, useValue:Object, named:String = null ):void
		{
			var whenAskedForClassName:String = ClassUtils.getFullyQualifiedName( whenAskedFor );
			var useClassName:String = ObjectUtils.getFullQualifiedClassName( useValue );
			var objdef:ObjectDefinition = new ObjectDefinition( useClassName );
			// how to store useValue instance?
			var key:String = named ? named : whenAskedForClassName;
			factory.registerObjectDefinition( key, objdef );
		}

		public function bindClass( whenAskedFor:Class, instantiateClass:Class, named:String = null ):void
		{
			var whenAskedForClassName:String = ClassUtils.getFullyQualifiedName( whenAskedFor );
			var useClassName:String = ClassUtils.getFullyQualifiedName( instantiateClass );
			var objdef:ObjectDefinition = new ObjectDefinition( useClassName );
			objdef.isSingleton = false;
			var key:String = named ? named : whenAskedForClassName;
			factory.registerObjectDefinition( key, objdef );
		}

		public function bindSingleton( whenAskedFor:Class, named:String = null ):void
		{
			var whenAskedForClassName:String = ClassUtils.getFullyQualifiedName( whenAskedFor );
			var objdef:ObjectDefinition = new ObjectDefinition( whenAskedForClassName );
			var key:String = named ? named : whenAskedForClassName;
			factory.registerObjectDefinition( key, objdef );
		}

		public function bindSingletonOf( whenAskedFor:Class, useSingletonOf:Class, named:String = null ):void
		{
			var whenAskedForClassName:String = ClassUtils.getFullyQualifiedName( whenAskedFor );
			var useClassName:String = ClassUtils.getFullyQualifiedName( useSingletonOf );
			var objdef:ObjectDefinition = new ObjectDefinition( useClassName );
			var key:String = named ? named : whenAskedForClassName;
			factory.registerObjectDefinition( key, objdef );
		}

		public function injectInto( target:Object ):void
		{
			var type:Type = Type.forInstance( target );
			var fields:Array = type.fields;
			for each ( var field:Field in fields )
			{
				if ( field.hasMetaData( 'Inject' ) )
				{
					var named:String;
					var mds:Array = field.getMetaData( 'Inject' );
					for each ( var md:MetaData in mds )
					{
						if ( md.hasArgumentWithKey( 'name' ) )
						{
							named = md.getArgument( 'name' ).value;
						}
						else if ( md.hasArgumentWithKey( 'id' ) )
						{
							named = md.getArgument( 'id' ).value;
						}
					}
					named = named ? named : field.type.fullName;
					target[ field.name ] = factory.getObject( named );
				}
			}
		}

		public function unbind( clazz:Class, named:String = null ):void
		{
			named = named ? named : ClassUtils.getFullyQualifiedName( clazz );
			factory.removeObjectDefinition( named );
		}

	}
}

[666shooter]

Hey there,

interesting to see how you're using Spring Actionscript in your own framework I'm trying to find out what the bindValue() method actually does though, is this when an instance's property needs to be injected by a managed value?

cheers,

Roland

[drscn]

Hi Roland,

Thanks for the response. bindValue is not as complicated as that though; it's simply a way to put an existing instance into the container and re-use it whenever it's needed (singleton scope). It's the same as bindClass, except bindValue works with existing instances, and bindClass will instantiate a new instance each time (prototype scope).

I've been combing through the docs, but haven't found any easy way to provide existing instances to containers/contexts/factories. Even implementing IFactoryObject doesn't seem to do the trick. I thought of a REALLY nasty way to do it (using static properties), but am pretty sure I would never be allowed to program anything ever again if I released it.

So, how do I register existing instances with a Spring container?

Many thanks,
Shaun

[666shooter]

Hi Shaun,

I can save you a bit of time combing through the documentation, its NOT possible currently to add an instance to the application context. The singleton cache is not exposed to the 'outside world' currently.

Its an interesting approach you're taking though, so I think we can consider a way of opening the container like this.

Best way of going about things for you right now is to submit a feature request in JIRA: http://jira.springframework.org/brow...ACTIONSCRIPTAS

If you have suggestions for implementing you can also attach a patch file with your code.

Right now we're busy getting the version 0.8 release out of the door, so I'm afraid we won't be adding the functionality very soon, please bear with us.

cheers,

Roland

[drscn]

Hi Roland,

Aha! Thanks for letting me know... my hacks were getting pretty gnarly. Perhaps I should check out the source, and see if I can come up with a patch - the problem at this point, however, is my flaky knowledge of Spring and it's philosophies.

Cheers,
Shaun

[666shooter]

Hey Shaun,

I know what you're talking about I wanted to get to know Spring AS better as well, so that was the main reason why I joined the team actually I volunteered to do the documentation, which would forced me to go through the entire code base back to front, that was a good way of getting to know what goes where
Mind you, I'm still not a guru, that's Christophe and Martino, but I'm getting there
I do recommend you check out the sources, right now we're busy re-structuring the SVN repository, so when you do a checkout make sure you only take the 'trunk' from the root of the repository, the other project directories in the root are all deprecated.
What you want to sift through first is the FlexXMLApplicationContext or XMLApplicationContext classes and their superclasses, this is the nucleus of the container.

If you have any questions along the way, feel free to ask them here.

-Roland

[drscn]

Hey Roland,

Thanks for pointing me in the right direction (especially with regards to the deprecated SVN root folders). I'll take a look into the IApplicationContext implementations and see if I can get anything going. Thanks for all your help

Cheers,
Shaun

[666shooter]

no problem Shaun, please keep us posted on your progress.

[666shooter]

Hey Shaun,

I did a little bit of digging for you last night, I think your best route would be to subclass the AbstractXMLObjectFactory (found in the org.springextensions.actionscript.ioc.factory.supp ort package). This class has a protected variable called singletonCache, in your subclass you can write methods that access this dictionary.
I don't think this kind of functionality will ever be part of the spring actionscript library itself, since its geared towards a very specific solution so for you it would be the best way to start 'rolling your own' from here.

Examine the getObject() method in the same AbstractXMLObjectFactory class to understand better how the singletonCache is being populated.

If you need help or info, you know here to find us.

cheers,

Roland

P.S. The field I mentioned used to be private, I changed it to protected only last night, so if you want to be able to pull this off you're gonna need the very latest source from the trunk.
Or you can just wait for the version 0.8 release, which will see the light today (hopefully if everything goes according to plan)

[drscn]

Above and beyond the call of duty sir! Thanks Roland, you rock. I'll jump in and see what I can put together (didn't get a chance yesterday). Cheers!