#BlackLivesMatter
AMP
  • websites

Conditional State

Introduction

This snippet demonstrates how to create a simple amp-state with conditions.

Setup

We use amp-bind to create a dynamic amp-state.

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

Basic usage

The charState is set by theAMP.setState block in the input component. We check whether the state of user input has changed by using input-throttled. If the state of input has changed, we check current the number of characters in the input (event.value.length) is. The number of characters determines what charState will be set. The item between the ? question mark and the : colon meets the stated condition. The item after the : colon is given for anything that does not meet the stated condition. It is possible to have multiple conditions within the same AMP.setState block.

When a user types < 10 characters in the input section, they see the message "There are under 10 characters, type more!".

When a user types > 10 characters in the input section, they see the message "You have typed over 10 characters, you can stop now.".

Try typing a few characters into the textbox.

<p [text]="charState">
  Try typing a few characters into the textbox.
</p>
<input type="textbox"
  on="input-throttled:AMP.setState({
    charState: event.value.length < 10 ?  
      'There are under 10 characters, type more!' : 
      'You have typed over 10 characters, you can stop now.'
    })">
需要进一步说明?

如果此页面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其中并作出贡献!我们希望您能成为我们开源社区的持续参与者,但我们也欢迎您对热衷问题做出单次贡献。

在 GitHub 上编辑实例