可扩展性

自定义选择器引擎

🌐 Custom selector engines

Playwright 支持自定义选择器引擎，可通过 Selectors.RegisterAsync() 注册。

🌐 Playwright supports custom selector engines, registered with Selectors.RegisterAsync().

选择器引擎应具有以下属性：

🌐 Selector engine should have the following properties:

query 函数用于查询相对于 root 的第一个匹配 selector 的元素。
queryAll 函数用于查询相对于 root 的所有匹配 selector 的元素。

默认情况下，引擎直接在框架的 JavaScript 上下文中运行，例如，可以调用应用定义的函数。要将引擎与框架中的任何 JavaScript 隔离，但仍保留对 DOM 的访问，请使用 {contentScript: true} 选项注册引擎。内容脚本引擎更安全，因为它不受全局对象的任何篡改影响，例如修改 Node.prototype 方法。所有内置的选择器引擎都作为内容脚本运行。请注意，当引擎与其他自定义引擎一起使用时，运行为内容脚本无法保证。

🌐 By default the engine is run directly in the frame's JavaScript context and, for example, can call an application-defined function. To isolate the engine from any JavaScript in the frame, but leave access to the DOM, register the engine with {contentScript: true} option. Content script engine is safer because it is protected from any tampering with the global objects, for example altering Node.prototype methods. All built-in selector engines run as content scripts. Note that running as a content script is not guaranteed when the engine is used together with other custom engines.

创建页面之前必须注册选择器。

🌐 Selectors must be registered before creating the page.

注册根据标签名称查询元素的选择器引擎的示例：

🌐 An example of registering selector engine that queries elements based on a tag name:

// Register the engine. Selectors will be prefixed with "tag=".
// The script is evaluated in the page context.
await playwright.Selectors.Register("tag", new() {
  Script = @"
  // Must evaluate to a selector engine instance.
  {
    // Returns the first element matching given selector in the root's subtree.
    query(root, selector) {
      return root.querySelector(selector);
    },

    // Returns all elements matching given selector in the root's subtree.
    queryAll(root, selector) {
      return Array.from(root.querySelectorAll(selector));
    }
  }"
});

// Now we can use "tag=" selectors.
await page.Locator("tag=button").ClickAsync();

// We can combine it with built-in locators.
await page.Locator("tag=div").GetByText("Click me").ClickAsync();

自定义选择器引擎​

自定义选择器引擎