Accordion sample using ngb-accordion. Trying to create accordion tabs that appear as "next" button is pressed.

<!DOCTYPE html>
<html>

  <head>
  <base href="." />
    <title>ng-bootstrap-to-bootstrap-3 demo</title>

    <!-- link Bootstrap 3 instead of Bootstrap 4 -->
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" />

    <!-- link CSS compatibility patch -->
    <link rel="stylesheet" href="https://unpkg.com/ng-bootstrap-to-bootstrap-3@0.7.0" />

    <script src="https://unpkg.com/zone.js@^0.7.2/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js@^0.7.2/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@^0.1.8/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@^0.19.40/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>

var ver = {
    ng: '2.3.1',
    ngRouter: '3.3.1'
  };
  
  System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  map: {

    'app': './src',

    '@angular/core': 'npm:@angular/core@' + ver.ng + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common@' + ver.ng + '/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler@' + ver.ng + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser@' + ver.ng + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic@' + ver.ng + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http@' + ver.ng + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router@' + ver.ngRouter + '/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms@' + ver.ng + '/bundles/forms.umd.js',

    'rxjs': 'npm:rxjs@5.0.0-rc.4',
    'typescript': 'npm:typescript@2.0.10/lib/typescript.js',

    '@ng-bootstrap/ng-bootstrap': 'npm:@ng-bootstrap/ng-bootstrap@1.0.0-alpha.21/bundles/ng-bootstrap.js'
  },
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

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

platformBrowserDynamic().bootstrapModule(AppModule);


import { Component, NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';
import { JsonpModule } from '@angular/http';
import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
import { NgbdAccordionBasic } from './accordion-basic';

@Component({
  selector: 'my-app',
  template: `
  <h4>Sample Accordion</h4>
  <div class="container-fluid">
    <ngbd-accordion-basic></ngbd-accordion-basic>
  </div>
  `
})
export class App {
}   

@NgModule({
  imports: [BrowserModule, FormsModule, ReactiveFormsModule, JsonpModule, NgbModule.forRoot()], 
  declarations: [App, NgbdAccordionBasic]
  bootstrap: [App]
}) 
export class AppModule {}

import { Component, ViewChild } from '@angular/core';
import { NgbPanelChangeEvent, NgbAccordion } from '@ng-bootstrap/ng-bootstrap';

@Component({
  selector: 'ngbd-accordion-basic',
  templateUrl: 'src/accordion-basic.html'
})
export class NgbdAccordionBasic {
  @ViewChild('acc') accordion: NgbAccordion;
  model = {};
  currentStep = 1;
  
  toggle(step) {
    this.currentStep = this.currentStep < step ? step : this.currentStep;
    setTimeout(() => this.accordion.toggle('toggle-' + step), 0);
  }
  
  beforeChange($event: NgbPanelChangeEvent) {
    const availStep = 'toggle-' + this.currentStep;
    if ($event.panelId > availStep) {
      $event.preventDefault();
    }
  };  
}


<ngb-accordion [closeOthers]="true" 
               activeIds="toggle-1" 
               #acc="ngbAccordion" 
               (panelChange)="beforeChange($event)">
  <ngb-panel id="toggle-1">
    <template ngbPanelTitle>
      <span>Title for Location</span>
    </template>    
    <template ngbPanelContent>
      <input type="text" 
             class="form-control" 
             name="location" 
             [(ngModel)]="model.location"
             #location
             placeholder="Some info" required>      
      <button type="submit"
              value="location-submitted"
              class="btn btn-primary blue-btn"
              (click)="toggle(2)"><!--showLoadNext = !showLoadNext-->
          Next
      </button>   
    </template>
  </ngb-panel>
  <ngb-panel id="toggle-2" *ngIf="currentStep > 1">
    <template ngbPanelTitle>
      <span>Title for Load</span>
    </template>
    <template ngbPanelContent>
      <div class="col-xs-12">
          <select class="form-control" id="select">
              <option>Selection 1</option>
              <option>Selection 2</option>
              <option>Selection 3</option>
          </select>
      </div>
      <button type="submit"
              value="load submitted"
              class="btn btn-primary blue-btn"
              (click)="toggle(3)"><!--showTariffNext = !showTariffNext-->
          Next
      </button>     
    </template>
  </ngb-panel>
  <ngb-panel id="toggle-3"  *ngIf="currentStep > 2">
    <template ngbPanelTitle>
      <span>Other</span>
    </template>    
    <template ngbPanelContent>
      Other.
      <div>
      <button type="submit"
              class="btn btn-primary">
          Submit
      </button>          
      </div>
    </template>
  </ngb-panel>
</ngb-accordion>