How to set up surveys in Angular

Jan 24, 2024

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Surveys are a great way to get feedback from your users. In this guide, we show you how to add a survey to your Angular.js app.

We'll create a basic Angular app, add PostHog, create a survey, and then show you how to display the survey in the app and get responses.

1. Create an Angular app

First, ensure Node.js is installed (version 14.20.0 or newer). Then, install the Angular CLI and create a new Angular app:

Terminal
npm install -g @angular/cli
ng new angular-surveys

Select CSS as your stylesheet and No for server side rendering and static site generation.

Next, Replace the code in src/app/app.component.html with a simple heading:

app.component.html
<div id="app">
  <h1>Angular Surveys</h1>
</div>

Run ng serve and navigate to http://localhost:4200 to see your app in action.

Basic Angular app

2. Add PostHog

We use PostHog to create and control our survey as well as monitor results. If you don't have a PostHog instance, you can sign up for free here.

To start, install the JavaScript web SDK:

Terminal
npm i posthog-js

In src/main.ts, initialize PostHog using your project API key and instance address. You can get both in your project settings.

main.ts
import { bootstrapApplication } from '@angular/platform-browser';
import { appConfig } from './app/app.config';
import { AppComponent } from './app/app.component';
import posthog from 'posthog-js'


posthog.init(
  '<ph_project_api_key>',
  {
    api_host:'https://us.i.posthog.com'
  }
)


bootstrapApplication(AppComponent, appConfig)
  .catch((err) => console.error(err));

Once you’ve done this, reload your app. You should see events appearing in the PostHog events explorer.

Events in PostHog

3. Create a survey

There are two options for displaying a survey using PostHog:

  1. Use PostHog's prebuilt survey UI.
  2. Implement your own survey UI.

This tutorial will cover how to implement both options:

Option 1: Use PostHog's prebuilt survey UI

This is the simplest option. PostHog has a variety of survey templates to choose from, handles all the display logic, and captures responses for you. You can also customize the questions, branding, and display conditions as needed – see our survey docs for more details on how to do so.

To create a survey with a prebuilt UI, go to the surveys tab in PostHog and click "New survey".

PostHog survey templates

Select any template, or you can create your own by clicking "Create blank survey". Then, configure your survey with the following details:

  1. Ensure Presentation is set to Popover.
  2. Set the display conditions to All users.
  3. Use the default values for everything else.

Then, click "Save as draft" and then "Launch". Your survey is now live and you should see it in your app. After submitting responses, you can view results in PostHog.

Popover survey in app

Option 2: Implement your own survey UI

If you prefer to have complete control of your survey UI and logic, you can still use PostHog to keep track of and analyze your results.

First, create a survey in PostHog like in option 1 above (for this tutorial, we use a Net Promoter Score survey template). The only difference is you must set Presentation to API.

Then, there are four parts to adding code for our custom survey:

  1. Create the survey UI.
  2. Fetch the survey from PostHog.
  3. Add the logic for displaying and hiding it.
  4. Capture interactions from it.

1. Create the survey UI

We've created a sample survey UI for this tutorial. To use it, first generate a new component using the Angular CLI:

Terminal
# In your base directory
ng generate component components/custom-survey

This creates a new component in the src/app/components/custom-survey directory. You'll have four files: custom-survey.component.ts, custom-survey.component.html, custom-survey.component.css, and custom-survey.component.spec.ts. You need to replace the code in three of them.

First, in custom-survey.component.html:

custom-survey.component.html
<div class="survey">
  <h2>{{ title }}</h2>
  <div>
    <button *ngFor="let i of numbers" class="button" (click)="handleSelect(i)">
      {{ i }}
    </button>
  </div>
  <div>
    <button class="button" (click)="emitDismiss()">Dismiss</button>
    <button class="button" (click)="emitSubmit()">Submit</button>
  </div>
</div>

Second, in custom-survey.component.ts:

custom-survey.component.ts
import { Component, EventEmitter, Input, Output } from '@angular/core';
import { CommonModule } from '@angular/common';


@Component({
  selector: 'app-custom-survey',
  standalone: true,
  imports: [CommonModule], 
  templateUrl: './custom-survey.component.html',
  styleUrls: ['./custom-survey.component.css']
})
export class CustomSurveyComponent {
  @Input() title!: string;
  @Output() onDismiss = new EventEmitter<void>();
  @Output() onSubmit = new EventEmitter<number>();


  selectedValue: number | undefined = undefined;
  numbers = Array.from({ length: 10 }, (_, i) => i + 1);


  handleSelect(value: number) {
    this.selectedValue = value;
  }


  emitDismiss() {
    this.onDismiss.emit();
  }


  emitSubmit() {
    this.onSubmit.emit(this.selectedValue);
  }
}

Third, in custom-survey.component.css:

custom-survey.component.css
.survey {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 400px;
  padding: 20px;
  background-color: #ffffff;
  box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.2);
  border-radius: 5px;
  z-index: 1000;
}


.button {
  margin: 5px;
  padding: 5px;
}

Now we integrate our new CustomSurveyComponent into our AppComponent. First, <app-custom-survey> to app.component.html:

app.component.html
<div id="app">
  <h1>Angular Surveys</h1>
    <app-custom-survey
      *ngIf="showSurvey"
      [title]="surveyTitle"
      (onDismiss)="handleDismiss()"
      (onSubmit)="handleSubmit($event)"
    />
</div>

Then, in app.component.ts, import CustomSurveyComponent and define the methods:

app.component.ts
import { Component } from '@angular/core';
import { RouterOutlet } from '@angular/router';
import { CommonModule } from '@angular/common';
import { CustomSurveyComponent } from './components/custom-survey/custom-survey.component';


@Component({
  selector: 'app-root',
  standalone: true,
  imports: [RouterOutlet, CustomSurveyComponent, CommonModule], 
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'angular-surveys';
  surveyTitle = 'Survey title';
  showSurvey = true;


  handleDismiss() {
    this.showSurvey = false;
  }


  handleSubmit(value: number) {
    console.log("Submitted value:", value);
    this.showSurvey = false;
  }
}

This shows a survey popup every time you visit your app's homepage.

Custom survey UI

2. Fetch the survey from PostHog

PostHog keeps track of all active surveys for a user (this is especially helpful if you set up custom display conditions).

To fetch the active surveys, we use posthog.getActiveMatchingSurveys(). This returns an array of survey objects that looks like this:

JSON
[
   {
     "id": "018cfcd5-107e-0000-49a1-8e7c6b825947",
     "name": "Net promoter score (NPS) API Survey",
     "description": "",
     "type": "api",
     "linked_flag_key": null,
     "targeting_flag_key": null,
     "questions": [
       {
         "type": "rating",
         "scale": 10,
         "display": "number",
         "question": "How likely are you to recommend us to a friend?",
         "description": "",
         "lowerBoundLabel": "Unlikely",
         "upperBoundLabel": "Very likely"
       }
     ],
     "conditions": null,
     "start_date": "2024-01-12T08:41:20.614000Z",
     "end_date": null
   }
]

To fetch this array and integrate it with your survey UI, update your code in app.component.ts:

app.component.ts
// Import OnInit and ChangeDetectorRef
import { Component, OnInit, ChangeDetectorRef } from '@angular/core';
import { RouterOutlet } from '@angular/router';
import { CommonModule } from '@angular/common';
import { CustomSurveyComponent } from './components/custom-survey/custom-survey.component';
import posthog from 'posthog-js'


@Component({
  // your existing config
})
export class AppComponent implements OnInit {
  title = 'angular-surveys';
  surveyTitle = 'Survey title';
  showSurvey = true;
  surveyID = '';


  constructor(private changeDetector: ChangeDetectorRef) {}


  ngOnInit(): void {
    this.fetchActiveSurveys();
  }


  private fetchActiveSurveys(): void {
    posthog.getActiveMatchingSurveys((surveys) => {
      if (surveys.length > 0) {
        const survey = surveys[0];
        this.surveyID = survey.id;
        this.surveyTitle = survey.questions[0].question;
        this.changeDetector.detectChanges();
      }
    });
  }


  handleDismiss(): void {
    // existing code
  }


  handleSubmit(value: number): void {
    // existing code
  }
}

3. Add the logic for displaying and hiding it.

We want to make sure we don't show the survey again to users who have either submitted or dismissed it. We use localStorage to store this data and use it to check whether to show the survey or not.

app.component.ts
// rest of your imports and code


export class AppComponent {
  title = 'angular-surveys';
  showSurvey = false; // updated to false


  // rest of code


  private fetchActiveSurveys(): void {
    posthog.getActiveMatchingSurveys((surveys) => {
      if (surveys.length > 0) {
        const survey = surveys[0];
        this.surveyID = survey.id;
        this.surveyTitle = survey.questions[0].question;
        this.checkSurveyInteraction();
        this.changeDetector.detectChanges();
      }
    });
  }


  private checkSurveyInteraction(): void {
    const hasInteractedWithSurvey = localStorage.getItem(`hasInteractedWithSurvey_${this.surveyID}`);
    this.showSurvey = !hasInteractedWithSurvey;
    this.changeDetector.detectChanges();
  }


  handleDismiss(): void {
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
  }


  handleSubmit(value: number): void {
    console.log("Submitted value:", value);
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
  }
}

4. Capture interactions from it.

The final step in setting up our survey is capturing interactions. This enables us to analyze the results in PostHog.

There are 3 events to capture:

  1. "survey shown"
  2. "survey dismissed"
  3. "survey sent" (for responses)

You can capture these events using this.$posthog.capture():

app.component.ts
// rest of your imports and code
export class AppComponent {
  // rest of your code


  private checkSurveyInteraction(): void {
    const hasInteractedWithSurvey = localStorage.getItem(`hasInteractedWithSurvey_${this.surveyID}`);
    this.showSurvey = !hasInteractedWithSurvey;
    this.changeDetector.detectChanges();
    if (this.showSurvey) {
      posthog.capture("survey shown", {
        $survey_id: this.surveyID // required
      })
    }
  }


  handleDismiss(): void {
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
    posthog.capture("survey dismissed", {
      $survey_id: this.surveyID // required
    })
  }


  handleSubmit(value: number): void {
    console.log("Submitted value:", value);
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
    posthog.capture("survey sent", {
      $survey_id: this.surveyID, // required
      $survey_response: `${value}` // required. Convert numbers to string
    })
  }
}

Altogether, your app.component.ts should look like this:

app.component.ts
import { Component, ChangeDetectorRef } from '@angular/core';
import posthog from 'posthog-js'
import { CommonModule } from '@angular/common';
import { RouterOutlet } from '@angular/router';
import { CustomSurveyComponent } from './components/custom-survey/custom-survey.component';


@Component({
  selector: 'app-root',
  standalone: true,
  imports: [RouterOutlet, CustomSurveyComponent, CommonModule], 
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'angular-surveys';
  showSurvey = false;
  surveyTitle = '';
  surveyID = '';


  constructor(private changeDetector: ChangeDetectorRef) {}


  ngOnInit(): void {
    this.fetchActiveSurveys();
  }


  private fetchActiveSurveys(): void {
    posthog.getActiveMatchingSurveys((surveys) => {
      console.log(surveys)
      if (surveys.length > 0) {
        const survey = surveys[0];
        this.surveyID = survey.id;
        this.surveyTitle = survey.questions[0].question;
        this.checkSurveyInteraction();
        this.changeDetector.detectChanges();
      }
    });
  }


  private checkSurveyInteraction(): void {
    const hasInteractedWithSurvey = localStorage.getItem(`hasInteractedWithSurvey_${this.surveyID}`);
    this.showSurvey = !hasInteractedWithSurvey;
    this.changeDetector.detectChanges();
    if (this.showSurvey) {
      posthog.capture("survey shown", {
        $survey_id: this.surveyID // required
      })
    }
  }


  handleDismiss(): void {
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
    posthog.capture("survey dismissed", {
      $survey_id: this.surveyID // required
    })
  }


  handleSubmit(value: number): void {
    console.log("Submitted value:", value);
    this.showSurvey = false;
    localStorage.setItem(`hasInteractedWithSurvey_${this.surveyID}`, 'true');
    posthog.capture("survey sent", {
      $survey_id: this.surveyID, // required
      $survey_response: `${value}` // required. Convert numbers to string
    })
  }
}

Our survey is now ready to go! The next step is to ship the changes, get responses, and view your results.

4. View results

After interacting with your survey, you can view results by selecting the survey from the surveys tab. You'll see data on:

  • How many users have seen the survey.
  • How many users have dismissed the survey.
  • Responses.

If you capture identified events, you can also filter these results based on person properties, cohorts, feature flags and more.

Survey results

Further reading

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