Introduction

JasFac is a powerful, light-weight Inversion of Control / Dependency Injection container for JavaScript.

The name 'JasFac' is a nod to Autofac, also found here on Google Code.

Details

JasFac allows you to:

• Register components as singletons or transient
• Register a component by providing a prototype
• Register a component by providing an expression (a closure that returns the component)
• Register a component by providing an instance (automatically flagged as singleton)
• Autowire constructor arguments
• Specify custom parameters for autowired constructors
• Specify properties to be injected on resolution
• Identify components by name, reference, or both
• Resolve components with custom arguments
• Resolve components with custom parameters

Examples

Sample container initialisation:

var builder = new JasFac.Builder();
var container = new JasFac.Container();

// register attempts to determine what you're registering
builder.register(
    function(c) { return new Foo(c.resolve("Bar")); }
).named("Foo");

// can explicitly register a constructor function. This will
// automatically call .as(), but you can also call .named()
builder.registerConstructor(Bar).injectArguments({
    arg1 : "value",
    arg2 : function(c) { c.resolve(FooBar); }
});

// set the scope
builder.register(Foobar)).named("Foobar").scoped(JasFac.Constants.SINGLETON);

// .injectProperties only works on non-initialised transients
builder.register(Foobar).named("Foobar").injectProperties({name: "override!"});

// After all registrations have been specified, build the container
// This will error if it detects required dependencies are missing
builder.build(container/*, true*/); // second arg is optional - specifies whether singletons should be initialised at build-time

Resolving is easy:

var foo = container.resolve("Foo");
var fooBar = container.resolve(FooBar);
var fooBarName = fooBar.name; // equals "override!" - this is injected as per the second registration of FooBar above