28 lines
765 B
TypeScript
28 lines
765 B
TypeScript
import {isBlank, CONST} from 'angular2/src/facade/lang';
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import {Pipe, BasePipe, WrappedValue, PipeFactory} from './pipe';
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import {ChangeDetectorRef} from '../change_detector_ref';
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@CONST()
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export class NullPipeFactory implements PipeFactory {
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supports(obj): boolean { return NullPipe.supportsObj(obj); }
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create(cdRef: ChangeDetectorRef): Pipe { return new NullPipe(); }
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}
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export class NullPipe extends BasePipe {
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called: boolean = false;
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static supportsObj(obj): boolean { return isBlank(obj); }
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supports(obj): boolean { return NullPipe.supportsObj(obj); }
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transform(value, args: List<any> = null): WrappedValue {
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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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