Chrome浏览器扩展程序chrome.app.isInstalled总是返回false？ [英] chrome.app.isInstalled always returns false for Google Chrome extensions?

问题描述

为什么chrome.app.isInstalled总是会为Google Chrome扩展程序返回false？

动态地在页面加载时添加一个链接元素：

 << ; link type =text / css =chrome-webstore-itemhref =https://chrome.google.com/webstore/detail/itemID> 
  

以下是点击按钮时执行的一些Javascript代码：

  if（！chrome.app.isInstalled）{
 alert（'extension is about to be installed！'）; 
 install_extension（）; 
} else {
 alert（'extension is installed already。'）; 
} 
  

第一次点击按钮时，Google Chrome问我是否想要安装扩展。我同意并且扩展已正确安装。当我刷新页面时，我再次点击该按钮，Google CHrome要求我再次安装扩展程序，即使在2分钟前安装了该扩展程序。换句话说，即使安装了扩展程序，chrome.app.isInstalled也总是返回false。为什么？

解决方案

请参阅 chrome.app.isInstalled始终返回为false：

chrome.app.isInstalled 适用于托管应用程序 strong>（它定义了一组包含应用程序的URL）。扩展可以反而表明它们已经通过在页面中注入DOM节点来安装（参见 https://developers.google.com/chrome/web-store/docs/inline_installation#already-installed ）。

该链接描述了测试您的扩展是否已安装的策略： 有一个内容脚本注入一个DOM节点到每个页面。这个节点应该有一个非常具体的ID，例如< div id ='my-extension-installed-with-id-sdgdthsdfgdtyjufwknsdkos'>

li>

如果该节点存在，则内容脚本正在运行;因此，扩展已安装。如果它不存在，则假定没有安装该扩展。

注入一个DOM节点不会影响状态 app.isInstalled 。相反，您会检查DOM节点的存在以证明扩展的存在。

why does chrome.app.isInstalled always return false for Google Chrome extensions?

Dynamically I add a link element on page load:

<link type="text/css" rel="chrome-webstore-item" href="https://chrome.google.com/webstore/detail/itemID">

The following is some Javascript that executes when a button has been clicked:

if (!chrome.app.isInstalled) {
 alert('extension is about to be installed!');
 install_extension();
}else{
  alert('extension is installed already.');
}

The first time I clicked the button, Google Chrome asked me if I wanted to install the extension. I agree and the extension was installed correctly. When I refreshed the page, I clicked the button once again and Google CHrome asked me to install the extension once again even when I had installed it 2 minutes ago. In other words, chrome.app.isInstalled always return false even when the extension is installed. Why?

解决方案

See chrome.app.isInstalled Always Returns as "false":

chrome.app.isInstalled is meant for use by hosted apps (which define a set of URLs that encompass the app). Extensions can instead indicate that they're installed already by injecting a DOM node into the page (see second half of https://developers.google.com/chrome/web-store/docs/inline_installation#already-installed).

That link describes a strategy for testing if your extension is installed:

1. Have a content script inject a DOM node into every page. This node should have a very specific ID, e.g., <div id='my-extension-installed-with-id-sdgdthsdfgdtyjufwknsdkos'>

2. On button press, have your page test if that node exists.

3. If the node exists, the content script is running; therefore, the extension is installed. If it does not exist, assume the extension is not installed.

Injecting a DOM node won't affect the state of app.isInstalled. Instead, you check for the existence of the DOM node as proof of the extensions presence.

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