2015-07-21 06:20:13 -07:00

440 lines
12 KiB
TypeScript

import {
Type,
isBlank,
isPresent,
CONST,
CONST_EXPR,
BaseException,
stringify,
isArray
} from 'angular2/src/facade/lang';
import {List, MapWrapper, ListWrapper} from 'angular2/src/facade/collection';
import {reflector} from 'angular2/src/reflection/reflection';
import {Key} from './key';
import {
InjectMetadata,
InjectableMetadata,
VisibilityMetadata,
OptionalMetadata,
DEFAULT_VISIBILITY,
DependencyMetadata
} from './metadata';
import {NoAnnotationError} from './exceptions';
import {resolveForwardRef} from './forward_ref';
/**
* @private
*/
export class Dependency {
constructor(public key: Key, public optional: boolean, public visibility: VisibilityMetadata,
public properties: List<any>) {}
static fromKey(key: Key): Dependency {
return new Dependency(key, false, DEFAULT_VISIBILITY, []);
}
}
const _EMPTY_LIST = CONST_EXPR([]);
/**
* Describes how the {@link Injector} should instantiate a given token.
*
* See {@link bind}.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* new Binding(String, { toValue: 'Hello' })
* ]);
*
* expect(injector.get(String)).toEqual('Hello');
* ```
*/
@CONST()
export class Binding {
/**
* Token used when retrieving this binding. Usually the `Type`.
*/
token;
/**
* Binds an interface to an implementation / subclass.
*
* ## Example
*
* Becuse `toAlias` and `toClass` are often confused, the example contains both use cases for easy
* comparison.
*
* ```javascript
*
* class Vehicle {}
*
* class Car extends Vehicle {}
*
* var injectorClass = Injector.resolveAndCreate([
* Car,
* new Binding(Vehicle, { toClass: Car })
* ]);
* var injectorAlias = Injector.resolveAndCreate([
* Car,
* new Binding(Vehicle, { toAlias: Car })
* ]);
*
* expect(injectorClass.get(Vehicle)).not.toBe(injectorClass.get(Car));
* expect(injectorClass.get(Vehicle) instanceof Car).toBe(true);
*
* expect(injectorAlias.get(Vehicle)).toBe(injectorAlias.get(Car));
* expect(injectorAlias.get(Vehicle) instanceof Car).toBe(true);
* ```
*/
toClass: Type;
/**
* Binds a key to a value.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* new Binding(String, { toValue: 'Hello' })
* ]);
*
* expect(injector.get(String)).toEqual('Hello');
* ```
*/
toValue;
/**
* Binds a key to the alias for an existing key.
*
* An alias means that {@link Injector} returns the same instance as if the alias token was used.
* This is in contrast to `toClass` where a separate instance of `toClass` is returned.
*
* ## Example
*
* Becuse `toAlias` and `toClass` are often confused the example contains both use cases for easy
* comparison.
*
* ```javascript
*
* class Vehicle {}
*
* class Car extends Vehicle {}
*
* var injectorAlias = Injector.resolveAndCreate([
* Car,
* new Binding(Vehicle, { toAlias: Car })
* ]);
* var injectorClass = Injector.resolveAndCreate([
* Car,
* new Binding(Vehicle, { toClass: Car })
* ]);
*
* expect(injectorAlias.get(Vehicle)).toBe(injectorAlias.get(Car));
* expect(injectorAlias.get(Vehicle) instanceof Car).toBe(true);
*
* expect(injectorClass.get(Vehicle)).not.toBe(injectorClass.get(Car));
* expect(injectorClass.get(Vehicle) instanceof Car).toBe(true);
* ```
*/
toAlias;
/**
* Binds a key to a function which computes the value.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* new Binding(Number, { toFactory: () => { return 1+2; }}),
* new Binding(String, { toFactory: (value) => { return "Value: " + value; },
* dependencies: [Number] })
* ]);
*
* expect(injector.get(Number)).toEqual(3);
* expect(injector.get(String)).toEqual('Value: 3');
* ```
*/
toFactory: Function;
/**
* Used in conjunction with `toFactory` and specifies a set of dependencies
* (as `token`s) which should be injected into the factory function.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* new Binding(Number, { toFactory: () => { return 1+2; }}),
* new Binding(String, { toFactory: (value) => { return "Value: " + value; },
* dependencies: [Number] })
* ]);
*
* expect(injector.get(Number)).toEqual(3);
* expect(injector.get(String)).toEqual('Value: 3');
* ```
*/
dependencies: List<any>;
constructor(
token,
{toClass, toValue, toAlias, toFactory, deps}:
{toClass?: Type, toValue?: any, toAlias?: any, toFactory?: Function, deps?: List<any>}) {
this.token = token;
this.toClass = toClass;
this.toValue = toValue;
this.toAlias = toAlias;
this.toFactory = toFactory;
this.dependencies = deps;
}
/**
* Converts the {@link Binding} into {@link ResolvedBinding}.
*
* {@link Injector} internally only uses {@link ResolvedBinding}, {@link Binding} contains
* convenience binding syntax.
*/
resolve(): ResolvedBinding {
var factoryFn: Function;
var resolvedDeps;
if (isPresent(this.toClass)) {
var toClass = resolveForwardRef(this.toClass);
factoryFn = reflector.factory(toClass);
resolvedDeps = _dependenciesFor(toClass);
} else if (isPresent(this.toAlias)) {
factoryFn = (aliasInstance) => aliasInstance;
resolvedDeps = [Dependency.fromKey(Key.get(this.toAlias))];
} else if (isPresent(this.toFactory)) {
factoryFn = this.toFactory;
resolvedDeps = _constructDependencies(this.toFactory, this.dependencies);
} else {
factoryFn = () => this.toValue;
resolvedDeps = _EMPTY_LIST;
}
return new ResolvedBinding(Key.get(this.token), factoryFn, resolvedDeps);
}
}
/**
* An internal resolved representation of a {@link Binding} used by the {@link Injector}.
*
* A {@link Binding} is resolved when it has a factory function. Binding to a class, alias, or
* value, are just convenience methods, as {@link Injector} only operates on calling factory
* functions.
*/
export class ResolvedBinding {
constructor(
/**
* A key, usually a `Type`.
*/
public key: Key,
/**
* Factory function which can return an instance of an object represented by a key.
*/
public factory: Function,
/**
* Arguments (dependencies) to the `factory` function.
*/
public dependencies: List<Dependency>) {}
}
/**
* Provides an API for imperatively constructing {@link Binding}s.
*
* This is only relevant for JavaScript. See {@link BindingBuilder}.
*
* ## Example
*
* ```javascript
* bind(MyInterface).toClass(MyClass)
*
* ```
*/
export function bind(token): BindingBuilder {
return new BindingBuilder(token);
}
/**
* Helper class for the {@link bind} function.
*/
export class BindingBuilder {
constructor(public token) {}
/**
* Binds an interface to an implementation / subclass.
*
* ## Example
*
* Because `toAlias` and `toClass` are often confused, the example contains both use cases for
* easy comparison.
*
* ```javascript
*
* class Vehicle {}
*
* class Car extends Vehicle {}
*
* var injectorClass = Injector.resolveAndCreate([
* Car,
* bind(Vehicle).toClass(Car)
* ]);
* var injectorAlias = Injector.resolveAndCreate([
* Car,
* bind(Vehicle).toAlias(Car)
* ]);
*
* expect(injectorClass.get(Vehicle)).not.toBe(injectorClass.get(Car));
* expect(injectorClass.get(Vehicle) instanceof Car).toBe(true);
*
* expect(injectorAlias.get(Vehicle)).toBe(injectorAlias.get(Car));
* expect(injectorAlias.get(Vehicle) instanceof Car).toBe(true);
* ```
*/
toClass(type: Type): Binding { return new Binding(this.token, {toClass: type}); }
/**
* Binds a key to a value.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* bind(String).toValue('Hello')
* ]);
*
* expect(injector.get(String)).toEqual('Hello');
* ```
*/
toValue(value: any): Binding { return new Binding(this.token, {toValue: value}); }
/**
* Binds a key to the alias for an existing key.
*
* An alias means that we will return the same instance as if the alias token was used. (This is
* in contrast to `toClass` where a separate instance of `toClass` will be returned.)
*
* ## Example
*
* Becuse `toAlias` and `toClass` are often confused, the example contains both use cases for easy
* comparison.
*
* ```javascript
*
* class Vehicle {}
*
* class Car extends Vehicle {}
*
* var injectorAlias = Injector.resolveAndCreate([
* Car,
* bind(Vehicle).toAlias(Car)
* ]);
* var injectorClass = Injector.resolveAndCreate([
* Car,
* bind(Vehicle).toClass(Car)
* ]);
*
* expect(injectorAlias.get(Vehicle)).toBe(injectorAlias.get(Car));
* expect(injectorAlias.get(Vehicle) instanceof Car).toBe(true);
*
* expect(injectorClass.get(Vehicle)).not.toBe(injectorClass.get(Car));
* expect(injectorClass.get(Vehicle) instanceof Car).toBe(true);
* ```
*/
toAlias(aliasToken: /*Type*/ any): Binding {
if (isBlank(aliasToken)) {
throw new BaseException(`Can not alias ${stringify(this.token)} to a blank value!`);
}
return new Binding(this.token, {toAlias: aliasToken});
}
/**
* Binds a key to a function which computes the value.
*
* ## Example
*
* ```javascript
* var injector = Injector.resolveAndCreate([
* bind(Number).toFactory(() => { return 1+2; }),
* bind(String).toFactory((v) => { return "Value: " + v; }, [Number])
* ]);
*
* expect(injector.get(Number)).toEqual(3);
* expect(injector.get(String)).toEqual('Value: 3');
* ```
*/
toFactory(factoryFunction: Function, dependencies?: List<any>): Binding {
return new Binding(this.token, {toFactory: factoryFunction, deps: dependencies});
}
}
function _constructDependencies(factoryFunction: Function, dependencies: List<any>):
List<Dependency> {
if (isBlank(dependencies)) {
return _dependenciesFor(factoryFunction);
} else {
var params: List<List<any>> = ListWrapper.map(dependencies, (t) => [t]);
return ListWrapper.map(dependencies, (t) => _extractToken(factoryFunction, t, params));
}
}
function _dependenciesFor(typeOrFunc): List<Dependency> {
var params = reflector.parameters(typeOrFunc);
if (isBlank(params)) return [];
if (ListWrapper.any(params, (p) => isBlank(p))) {
throw new NoAnnotationError(typeOrFunc, params);
}
return ListWrapper.map(params, (p: List<any>) => _extractToken(typeOrFunc, p, params));
}
function _extractToken(typeOrFunc, annotations /*List<any> | any*/, params: List<List<any>>):
Dependency {
var depProps = [];
var token = null;
var optional = false;
if (!isArray(annotations)) {
return _createDependency(annotations, optional, DEFAULT_VISIBILITY, depProps);
}
var visibility = DEFAULT_VISIBILITY;
for (var i = 0; i < annotations.length; ++i) {
var paramAnnotation = annotations[i];
if (paramAnnotation instanceof Type) {
token = paramAnnotation;
} else if (paramAnnotation instanceof InjectMetadata) {
token = paramAnnotation.token;
} else if (paramAnnotation instanceof OptionalMetadata) {
optional = true;
} else if (paramAnnotation instanceof VisibilityMetadata) {
visibility = paramAnnotation;
} else if (paramAnnotation instanceof DependencyMetadata) {
if (isPresent(paramAnnotation.token)) {
token = paramAnnotation.token;
}
depProps.push(paramAnnotation);
}
}
token = resolveForwardRef(token);
if (isPresent(token)) {
return _createDependency(token, optional, visibility, depProps);
} else {
throw new NoAnnotationError(typeOrFunc, params);
}
}
function _createDependency(token, optional, visibility, depProps): Dependency {
return new Dependency(Key.get(token), optional, visibility, depProps);
}