Panda.Ioc - What can you inject

Where to inject?

There are two entries where you can inject values into the object.

Constructor parameters
Property

Inject parameters into the constructor

Your JSON configuration file will be like this:

{
	tom : {
		type : 'panda.demo.ioc.json.Pet',
		args : ['Tom']
	}
}

The value of args is an array where each element will correspond to a parameter of the constructor. Of course, you must ensure that you have such a constructor.

Injecting parameters into properties

Your JSON configuration file will be like this:

{
	tom : {
		type : 'panda.demo.ioc.json.Pet',
		fields : {
			name : 'Tom'
		}
	}
}

If you do not need to write type, then you can use shorthand mode:

{
	tom: { name: 'Tom' }
}

The value can be more than just a string, it can also be of the following type.

Boolean

{
	tom : { dead: true }
}

Number

{
	tom : { age: 24 }
}

Anonymous Object

{
	tom : {
		friend: {
			type : 'panda.demo.ioc.json.Pet',
			fields : { name : 'Jerry' }
		}
	}
}

For anonymous objects, see here.

Reference

{
	tom : { friend: '#jerry' }
}

friend: ‘#jerry’ will refer to another object named “jerry” in the container

IOC container ifself

{
	tom : { myIoc : '#$Ioc' }
}

A special reference, case insensitive, the value is the Ioc container itself

Object Name

{
	tom : { beanName : '#$Name'}
}

A special reference, case insensitive, the value is the name of the object, ie “tom”

IOC Container Context

{
	tom : { myContext : '#$Ctx' }
}

A special reference, case insensitive, the value is the context (interface panda.ioc.IocContext) of the current IOC container

JSON Object/Array

If your object’s field is an array, collection, or Map, it’s natural to set its value using JSON, isn’t it?

{
	tom : { favorites: [ 'banana', 'bug' ] }
}

{
	tom : { favorites: "![ 'banana', 'bug' ]" }
}

EL Expression

This is an extremely flexible injection method that allows you to do almost anything. Because it allows you to directly call a Java method.

For a more detailed description, see EL Expression.

Here are just a few of the major ways of using:

Static Property

{
	tom : { staticField : "${'com.my.SomeClass'@staticPropertyName}" }
}

Static Method

{
	tom : { staticField : "${'com.my.SomeClass'@staticFunc()}" }
}

Static Method with parameters (parameters can be any type)

{
	tom : { staticField : "${'com.my.SomeClass'@staticFunc('param', true)}" }
}

Object in the IOC container

{
	tom : { friend: '${jerry}' },
	jerry : { type : 'com.my.Pet' }
}

Property of the object in the IOC container

{
	tom : { oneField : '${jerry.name}' } ,
	jerry : { type: 'com.my.Pet'}
}

Method’s return value of the object in the IOC container

{
	tom : { oneField : '${jerry.getXXX()}' } ,
	jerry : { type: 'com.my.Pet'}
}

Method’s return value of the object in the IOC container (with parameters)

{
	tom : { oneField : '${jerry.getXXX("some string", true, 34)}' } ,
	jerry : { type: 'com.my.Pet'}
}