AMP
PT
English Deutsch Français العربية Español Italiano Indonesia 日本語 한국어 Русский Türkçe 中文 Polski Tiếng việt

Important: this documentation is not applicable to your currently selected format email!

amp-font

Deprecated

Description

Trigger and monitor the loading of custom fonts on AMP pages.

 

Required Scripts

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

Supported Layouts

This component is deprecated and should no longer be used. Instead, use the font-display descriptor to specify how to display a font face dependent on whether and when it is ready.

The amp-font component was AMP's solution to controlling timeouts on font loading. With the wide browser adoption of font-display, this component is no longer necessary. It is here for legacy users. Instead, use the font-display descriptor to specify how to display a font face dependent on whether and when it is ready.

Usage

Historically, the amp-font extension was used for controlling timeouts on font loading. We recommend implementing this functionality with font-display instead.

The amp-font extension allows adding and removing CSS classes from document.documentElement or document.body based on whether a font was loaded or is in error-state.

Example:

<amp-font
  layout="nodisplay"
  font-family="My Font"
  timeout="3000"
  on-error-remove-class="my-font-loading"
  on-error-add-class="my-font-missing"
></amp-font>
<amp-font
  layout="nodisplay"
  font-family="My Other Font"
  timeout="1000"
  on-load-add-class="my-other-font-loaded"
  on-load-remove-class="my-other-font-loading"
></amp-font>

The component observes loading of a font. When the font successfully loads it executes the optional on-load-add-class and on-load-remove-class attributes. If the font loading results in an error or timeout, it runs on-error-remove-class and on-error-add-class. These classes toggle on the documentElement for standalone documents, and on body for documents without a documentElement i.e. inside a ShadowRoot.

Use these classes to guard against displaying a font and get the following results:

  • get a short (e.g. 3000ms) timeout in Safari similar to other browsers
  • implement FOIT where the page renders with no text before the font comes in
  • make the timeout very short and only use a font if it was already cached.

Attributes

font-family

The font family of the custom loaded font.

timeout (optional)

The allowed time in millisecond for the custom font to load. Defaults to 3000 when undefined. When set to 0 the component loads font only if the font is in the cache. If set to an invalid value it defaults back to 3000.

on-load-add-class (optional)

CSS class to add to document root after custom font is available.

on-load-remove-class (optional)

CSS class to remove from document root after custom font is available.

on-error-add-class (optional)

CSS class to add to the document root if the timeout interval runs out before the font is available.

on-error-remove-class (optional)

CSS class to remove from document root if the timeout interval runs out before the font is available.

font-weight (optional)

Behaves same as standard CSS font-weight property.

font-style (optional)

Behaves same as standard CSS font-style property.

font-variant (optional)

Behaves same as standard CSS font-variant property.

layout

The layout attribute must be set to nodisplay.

Validation

See amp-font rules in the AMP validator specification.

Precisa de mais ajuda?

Você já leu este documento várias vezes, mas ainda ficou com dúvidas sem respostas? Talvez outras pessoas pensem da mesma forma. Procure entrar em contato com elas no Stack Overflow.

Ir para o Stack Overflow
Encontrou um bug ou sente falta de um recurso?

O projeto AMP incentiva fortemente sua participação e contribuições! Esperamos que você se torne um participante assíduo de nossa comunidade de código aberto, mas também agradecemos contribuições pontuais para problemas que você tenha particular interesse.

Ir para o GitHub