39 lines
782 B
TypeScript
39 lines
782 B
TypeScript
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import {isBlank, CONST} from 'angular2/src/facade/lang';
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import {Pipe, WrappedValue, PipeFactory} from './pipe';
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/**
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* @exportedAs angular2/pipes
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*/
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@CONST()
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export class NullPipeFactory extends PipeFactory {
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constructor() { super(); }
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supports(obj): boolean { return NullPipe.supportsObj(obj); }
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create(cdRef): Pipe { return new NullPipe(); }
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}
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/**
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* @exportedAs angular2/pipes
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*/
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export class NullPipe extends Pipe {
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called: boolean;
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constructor() {
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super();
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this.called = false;
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}
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static supportsObj(obj): boolean { return isBlank(obj); }
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supports(obj) { return NullPipe.supportsObj(obj); }
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transform(value) {
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if (!this.called) {
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this.called = true;
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return WrappedValue.wrap(null);
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} else {
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return null;
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}
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}
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}
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