import { Pipe, PipeTransform } from '@angular/core';
import { DomSanitizer, SafeHtml, SafeStyle, SafeScript, SafeResourceUrl, SafeUrl } from '@angular/platform-browser';

@Pipe({
  name: 'filterSafe',
})

export class FilterSafePipe implements PipeTransform {

 constructor(private _sanitizer: DomSanitizer) {

}
 public transform(value: any, type: string): SafeHtml | SafeStyle | SafeScript | SafeResourceUrl | SafeUrl {
   switch (type) {
    // 这条语句就是我们今天主要用到的
    case 'html': return this._sanitizer.bypassSecurityTrustHtml(value); 
  
    // 接下来的这些是DomSanitizer提供的其他一些安全的转换
    case 'style': return this._sanitizer.bypassSecurityTrustStyle(value);
    case 'script': return this._sanitizer.bypassSecurityTrustScript(value);
    case 'url': return this._sanitizer.bypassSecurityTrustUrl(value);
    case 'resourceUrl': return this._sanitizer.bypassSecurityTrustResourceUrl(value);
    default: throw new Error(`Invalid safe type specified: ${type}`);
  }
}
}