Angular Text Masking Pipe

import { Component } from "@angular/core";

@Component({
  selector: 'app-root',
  template: `
    <h1>Angular Text Masking Pipe</h1>
    <app-credit-card></app-credit-card>
  `
})
export class AppComponent {}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

import { CreditCardModule } from '../credit-card/credit-card.module';
import { AppComponent } from './app.component';

@NgModule({
  imports: [
    BrowserModule,
    CreditCardModule.forRoot()
  ],
  declarations: [AppComponent],
  bootstrap: [AppComponent]
})
export class AppModule { }

<!DOCTYPE html>
<html>
  <head>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <title>NgModule Deluxe</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://npmcdn.com/core-js/client/shim.min.js"></script>
    <script src="https://npmcdn.com/zone.js@0.6.25?main=browser"></script>
    <script src="https://npmcdn.com/reflect-metadata@0.1.3"></script>
    <script src="https://npmcdn.com/systemjs@0.19.27/dist/system.src.js"></script>
    <script src="systemjs.config.js"></script>
    <script>
      System.import('main.ts').catch(function(err){ console.error(err); });
    </script>
  </head>

  <body>
    <app-root>Loading...</app-root>
  </body>
</html>

/**
 * PLUNKER VERSION (based on systemjs.config.js in angular.io)
 * System configuration for Angular 2 samples
 * Adjust as necessary for your application needs.
 */
(function(global) {

  var ngVer = '@2.0.0'; // lock in the angular package version; do not let it float to current!
  var routerVer = '@3.0.0'; // lock router version
  var formsVer = '@2.0.0'; // lock forms version
  var routerDeprecatedVer = '@2.0.0-rc.2'; // temporarily until we update all the guides

  //map tells the System loader where to look for things
  var map = {
    'app':                        'app',
    'credit-card':                'credit-card',

    '@angular':                   'https://npmcdn.com/@angular', // sufficient if we didn't pin the version
    '@angular/router':            'https://npmcdn.com/@angular/router' + routerVer,
    '@angular/forms':             'https://npmcdn.com/@angular/forms' + formsVer,
    '@angular/router-deprecated': 'https://npmcdn.com/@angular/router-deprecated' + routerDeprecatedVer,
    'angular2-in-memory-web-api': 'https://npmcdn.com/angular2-in-memory-web-api', // get latest
    'rxjs':                       'https://npmcdn.com/rxjs@5.0.0-beta.12',
    'ts':                         'https://npmcdn.com/plugin-typescript@4.0.10/lib/plugin.js',
    'typescript':                 'https://npmcdn.com/typescript@2.0.2/lib/typescript.js',
 };

  //packages tells the System loader how to load when no filename and/or no extension
  var packages = {
    'app':                        { main: 'main.ts',  defaultExtension: 'ts' },
    'credit-card':                { defaultExtension: 'ts' },
    'rxjs':                       { defaultExtension: 'js' },
    'angular2-in-memory-web-api': { main: 'index.js', defaultExtension: 'js' },
  };

  var ngPackageNames = [
    'common',
    'compiler',
    'core',
    'http',
    'platform-browser',
    'platform-browser-dynamic',
    'upgrade',
  ];

  // Add map entries for each angular package
  // only because we're pinning the version with `ngVer`.
  ngPackageNames.forEach(function(pkgName) {
    map['@angular/'+pkgName] = 'https://npmcdn.com/@angular/' + pkgName + ngVer;
  });

  // Add package entries for angular packages
  ngPackageNames.concat(['forms', 'router', 'router-deprecated']).forEach(function(pkgName) {

    // Bundled (~40 requests):
    packages['@angular/'+pkgName] = { main: '/bundles/' + pkgName + '.umd.js', defaultExtension: 'js' };

    // Individual files (~300 requests):
    //packages['@angular/'+pkgName] = { main: 'index.js', defaultExtension: 'js' };
  });

  var config = {
    // DEMO ONLY! REAL CODE SHOULD NOT TRANSPILE IN THE BROWSER
    transpiler: 'ts',
    typescriptOptions: {
      tsconfig: true
    },
    meta: {
      'typescript': {
        "exports": "ts"
      }
    },
    map: map,
    packages: packages
  };

  System.config(config);

})(this);


/*
Copyright 2016 Google Inc. All Rights Reserved.
Use of this source code is governed by an MIT-style license that
can be found in the LICENSE file at http://angular.io/license
*/

{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "moduleResolution": "node",
    "sourceMap": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "removeComments": false,
    "noImplicitAny": true,
    "suppressImplicitAnyIndexErrors": true
  }
}

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';

import { CreditCardMaskPipe } from './credit-card-mask.pipe';
import { CreditCardService } from './credit-card.service';
import { CreditCardComponent } from './credit-card.component';

@NgModule({
  imports: [CommonModule],
  declarations: [
    CreditCardMaskPipe,
    CreditCardComponent
  ],
  exports: [CreditCardComponent]
})
export class CreditCardModule {
  static forRoot(): ModuleWithProviders {
    return {
      ngModule: CreditCardModule,
      providers: [CreditCardService]
    }
  }
}

import { Component, OnInit } from '@angular/core';
import { CreditCardService } from './credit-card.service';

@Component({
  selector: 'app-credit-card',
  template: `
    <p>Your credit card is: {{ creditCardNumber | creditCardMask:3 }}</p>
  `
})
export class CreditCardComponent implements OnInit {
  creditCardNumber: string;

  constructor(private creditCardService: CreditCardService) {}

  ngOnInit() {
    this.creditCardNumber = this.creditCardService.getCreditCard();
  }
}

import { Injectable } from '@angular/core';

@Injectable()
export class CreditCardService {
  getCreditCard(): string {
    return '2131313133123174098';
  }
}

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'creditCardMask'
})
export class CreditCardMaskPipe implements PipeTransform {
  transform(plainCreditCard: string, visibleDigits: number = 4): string {
    //const visibleDigits = 4;
    let maskedSection = plainCreditCard.slice(0, -visibleDigits);
    let visibleSection = plainCreditCard.slice(-visibleDigits);
    return maskedSection.replace(/./g, '*') + visibleSection;
  }
}

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { AppModule } from './app/app.module';

platformBrowserDynamic().bootstrapModule(AppModule);