• websites

Server Side User Consent Flow

Introduction

Sometimes is necessary to rely on external servers for consent due to needing to sync user consent between multiple platforms. This sample demonstrates how you can use amp-consent to achieve this. In this sample we'll build a consent dialog that will only show based upon the consent state from external servers.

Setup

We need to import the amp-consent extension...

<script async custom-element="amp-consent" src="https://cdn.ampproject.org/v0/amp-consent-0.1.js"></script>

Defining the consent flow

We define a basic server-side consent flow, similar to this sample. The flow should only trigger when the server responds that consentRequired is true and there is no consentStateValue or consentString for this user.

When a user lands on the AMP page, amp-consent will check localstorage for an existing consent state. If a consent state exists, it will unblock all components. Otherwise, it will wait for the response from checkConsentHref (because consentRequired is set to 'remote') to determine if consent is required/if there is an existing consent state. If there is an existing consent state, amp-consent will use that value and unblock. Otherwise, it will show the promptUi.

A recommended design for sites that can manage their own consent (via external page) is to respond with the following response:

{
  "consentRequired": true,
  "consentStateValue": "accepted"/"rejected"/"unknown",
  "consentString": "example-string"
}

<amp-consent id="myUserConsent" layout="nodisplay">
  <script type="application/json">{
    "consentInstanceId": "server-side-consent",
    "consentRequired": "remote",
    "checkConsentHref": "https://amp.dev/documentation/examples/api/get-consent-server-side",
    "promptUI": "myConsentFlow"
  }</script>
  <div id="myConsentFlow" class="popupOverlay">
    <div class="consentPopup">
      <div class="dismiss-button" role="button" tabindex="0" on="tap:myUserConsent.dismiss">X</div>
      <h2>Headline</h2>
      <p>If the server says you have not made a consent decision, we require you to make a choice.</p>
      <button on="tap:myUserConsent.accept">Accept</button>
      <button on="tap:myUserConsent.reject">Reject</button>
    </div>
  </div>
  <div id="post-consent-ui">
    <button on="tap:myUserConsent.prompt()">Update Consent</button>
  </div>
</amp-consent>

• Written by @micajuine-ho and @sebastianbenz