angular-cn/modules/@angular/compiler/src/pipe_resolver.ts

46 lines
1.2 KiB
TypeScript
Raw Normal View History

import {resolveForwardRef, Injectable, PipeMetadata, reflector} from '@angular/core';
2016-05-02 01:50:37 -04:00
import {ReflectorReader} from '../core_private';
import {Type, isPresent, stringify} from '../src/facade/lang';
import {BaseException} from '../src/facade/exceptions';
2015-10-23 02:35:53 -04:00
function _isPipeMetadata(type: any): boolean {
return type instanceof PipeMetadata;
}
/**
* Resolve a `Type` for {@link PipeMetadata}.
*
* This interface can be overridden by the application developer to create custom behavior.
*
* See {@link Compiler}
*/
@Injectable()
export class PipeResolver {
private _reflector: ReflectorReader;
constructor(_reflector?: ReflectorReader) {
if (isPresent(_reflector)) {
this._reflector = _reflector;
} else {
this._reflector = reflector;
}
}
/**
* Return {@link PipeMetadata} for a given `Type`.
*/
resolve(type: Type): PipeMetadata {
var metas = this._reflector.annotations(resolveForwardRef(type));
if (isPresent(metas)) {
var annotation = metas.find(_isPipeMetadata);
2015-10-23 02:35:53 -04:00
if (isPresent(annotation)) {
return annotation;
}
}
throw new BaseException(`No Pipe decorator found on ${stringify(type)}`);
}
}
export var CODEGEN_PIPE_RESOLVER = new PipeResolver(reflector);