162 lines
3.2 KiB
Plaintext
162 lines
3.2 KiB
Plaintext
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p.location-badge.
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exported from <a href='../di'>angular2/di</a>
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defined in <a href="https://github.com/angular/angular/tree/3a0410a/modules/angular2/src/di/injector.ts#L27-L256">angular2/src/di/injector.ts (line 27)</a>
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:markdown
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A dependency injection container used for resolving dependencies.
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An `Injector` is a replacement for a `new` operator, which can automatically resolve the
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constructor dependencies.
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In typical use, application code asks for the dependencies in the constructor and they are
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resolved by the `Injector`.
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## Example:
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Suppose that we want to inject an `Engine` into class `Car`, we would define it like this:
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```javascript
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class Engine {
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}
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class Car {
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constructor(@Inject(Engine) engine) {
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}
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}
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```
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Next we need to write the code that creates and instantiates the `Injector`. We then ask for the
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`root` object, `Car`, so that the `Injector` can recursively build all of that object's
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dependencies.
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```javascript
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main() {
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var injector = Injector.resolveAndCreate([Car, Engine]);
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// Get a reference to the `root` object, which will recursively instantiate the tree.
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var car = injector.get(Car);
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}
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```
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Notice that we don't use the `new` operator because we explicitly want to have the `Injector`
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resolve all of the object's dependencies automatically.
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.l-main-section
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h2 Members
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.l-sub-section
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h3 constructor
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pre.prettyprint
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code.
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constructor(_bindings: List<ResolvedBinding>, _parent: Injector, _defaultBindings: boolean)
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:markdown
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.l-sub-section
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h3 parent
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:markdown
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Direct parent of this injector.
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.l-sub-section
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h3 get
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pre.prettyprint
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code.
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get(token)
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:markdown
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Retrieves an instance from the injector.
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.l-sub-section
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h3 getOptional
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pre.prettyprint
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code.
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getOptional(token)
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:markdown
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Retrieves an instance from the injector.
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.l-sub-section
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h3 asyncGet
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pre.prettyprint
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code.
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asyncGet(token)
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:markdown
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Retrieves an instance from the injector asynchronously. Used with asynchronous bindings.
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.l-sub-section
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h3 resolveAndCreateChild
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pre.prettyprint
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code.
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resolveAndCreateChild(bindings: List<Type | Binding | List<any>>)
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:markdown
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Creates a child injector and loads a new set of bindings into it.
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A resolution is a process of flattening multiple nested lists and converting individual
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bindings into a list of <a href='ResolvedBinding-class.html'><code>ResolvedBinding</code></a>s. The resolution can be cached by `resolve`
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for the <a href='Injector-class.html'><code>Injector</code></a> for performance-sensitive code.
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.l-sub-section
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h3 createChildFromResolved
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pre.prettyprint
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code.
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createChildFromResolved(bindings: List<ResolvedBinding>)
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:markdown
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Creates a child injector and loads a new set of <a href='ResolvedBinding-class.html'><code>ResolvedBinding</code></a>s into it.
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