amp-dynamic-css-classes

Introduction

AMP's dynamic CSS classes provided by the amp-dynamic-css-class enable boolean logic for a handful of conditions

Setup

Include the amp-dynamic-css-classes extended component.

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

For the purpose of this sample, we're creating some helper CSS classes that use the CSS rules defined by amp-dynamic-css-classes. These allow us to more succinctly refer to the conditions in our code below.

<style amp-custom>
  :root {
    --space-2: 1rem;   /* 16px */
  }
  body:not(.amp-referrer-pinterest-com) .if-pinterest,
  body:not(.amp-referrer-ampbyexample-com) .if-ampbyexample,
  body:not(.amp-referrer-google-com) .if-google,
  body:not(.amp-referrer-twitter-com) .if-twitter,
  body:not(.amp-referrer-linkedin-com) .if-linkedin,
  body:not(.amp-referrer-localhost) .if-localhost {
    display: none;
  }
  body:not(.amp-viewer) .if-viewer,
  body.amp-viewer .if-not-viewer {
    display: none;
  }
  .dynamic-css {
    padding: var(--space-2);
  }
</style>

Referrer

Using these referrer classes can allow you to conditionally include elements. You do not need to include a call to the amp-dynamic-css-classes component to initialize the classes on the body element.

You were referred here or embedded by Pinterest!

You were referred here or embedded by Twitter!

You were referred here or embedded by Google!

You came here directly! Cool :)

<div class="if-pinterest dynamic-css">You were referred here or embedded by Pinterest!</div>
<div class="if-twitter dynamic-css">You were referred here or embedded by Twitter!</div>
<div class="if-google dynamic-css">You were referred here or embedded by Google!</div>
<div class="if-ampbyexample dynamic-css">You came here directly!  Cool :)</div>
<div class="if-localhost dynamic-css">You came here directly!  Cool :)</div>

Viewer

The 'viewer' classes enable you to style the page based on whether it's embedded inside an AMP viewer. Try it out on the Google AMP Viewer. Note this works only on a mobile device or in your browser's mobile emulation mode.

Hey! You're not visiting within the context of an AMP Viewer!

Ahoy! Since you're coming from a viewer.

<div class="if-not-viewer dynamic-css">Hey! You're not visiting within the context of an AMP Viewer!</div>
<div class="if-viewer dynamic-css">Ahoy! Since you're coming from a viewer.</div>

需要进一步说明？

如果此页面上的说明未能涵盖您的所有问题，欢迎与其他 AMP 用户取得联系，讨论您的具体用例。

前往 Stack Overflow

一项无法解释的功能？

AMP 项目强烈鼓励您参与并做出贡献！我们希望您能成为我们开放源代码社区的持续参与者，但我们也欢迎您对所热衷问题做出一次性贡献。

编辑 GitHub 上的示例

Written by @jmadler