queryparam routing

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<html>

  <head>
    <base href="." />
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
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    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

/* Styles go here */

### Angular Starter Plunker - Typescript

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    
    '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

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

platformBrowserDynamic().bootstrapModule(AppModule)

import {NgModule} from '@angular/core';
import { LocationStrategy, HashLocationStrategy } from '@angular/common';
import {BrowserModule} from '@angular/platform-browser';
import {AppComponent} from './app.component';
import { CalculatorComponent } from './app-calculator.component';
import { CalculatorTwoComponent } from './app-calculator-two.component';
import { Routes, RouterModule} from '@angular/router';

const routes: Routes = [
  {
    path: 'calculator',
    component: CalculatorComponent
  },
  {
    path: 'calculatorTwo',
    component: CalculatorTwoComponent
  }
];

@NgModule({
  imports: [
    BrowserModule,
    RouterModule.forRoot(routes)
  ],
  declarations: [ AppComponent, CalculatorComponent, CalculatorTwoComponent ],
  bootstrap: [ AppComponent ],
  providers: [
    {provide: LocationStrategy, useClass: HashLocationStrategy}
  ]
  
})
export class AppModule {}

import {Component, OnInit} from '@angular/core';
import { ActivatedRoute, Router } from '@angular/router';

@Component({
  selector: 'app-calculator-component',
  template: `
    <div>
      <h3>Calc Component Parameters: {{qparameters | json}}</h3>
    </div>
  `
})
export class CalculatorComponent implements OnInit {
  qparameters: any;

  constructor(private router: Router, private route: ActivatedRoute) {
    this.route.queryParamMap.subscribe(params => {
      this.qparameters = params;
    })
  }
  
  ngOnInit() {
    
  }
}



//our root app component
import {Component, OnInit, VERSION} from '@angular/core';
import {Router, ActivatedRoute} from '@angular/router';

@Component({
  selector: 'my-app',
  template: `
    <div>App params: {{parameters | json}}</div>
    <router-outlet></router-outlet>
    <button (click)="c1Navigate()">Keeps Params</button>
    <button (click)="c2Navigate()">Drops Params</button>
  `,
})
export class AppComponent implements OnInit {
  parameters: any;

  constructor(private router: Router, private route: ActivatedRoute) {
    this.route.queryParamMap.subscribe(params => {
      this.parameters = params;
    });
    //this.c1Navigate(); // <- The problem is here
  }
  
  ngOnInit() {

  }
  
  public c1Navigate() {
    let navigationExtras: NavigationExtras = {
      queryParamsHandling: 'preserve',
    };
    this.router.navigate(['/calculator'], navigationExtras);
  }
  
  public c2Navigate() {
    this.router.navigate(['/calculatorTwo']);
  }
}

import {Component, OnInit} from '@angular/core';
import { ActivatedRoute, Router } from '@angular/router';

@Component({
  selector: 'app-calculator-two-component',
  template: `
    <div>
      <h3>Calc2 Component Parameters: {{qparameters | json}}</h3>
    </div>
  `
})
export class CalculatorTwoComponent implements OnInit {
  qparameters: any;

  constructor(private router: Router, private route: ActivatedRoute) {
    this.route.queryParamMap.subscribe(params => {
      this.qparameters = params;
    })
  }
  
  ngOnInit() {
    
  }
}