DOMContentLoaded
DOMContentLoaded事件是當document被完整的讀取跟解析後就會被觸發,不會等待 stylesheets, 圖片和 subframes 完成讀取 (load事件可以用來作為判斷頁面已經完整讀取的方法).
備註： Stylesheet loads block script execution, 如果 <script> 被放在 <link rel="stylesheet" ...>後面的話, 須等到前面的 stylesheet 載入並完成解析，此時 DOMContentLoaded才會被觸發。
Speeding up
If you want DOM to get parsed as fast as possible after the user had requested the page, some things you could do is turn your JavaScript asynchronous and to optimize loading of stylesheets which if used as usual, slow down page load due to being loaded in parallel, "stealing" traffic from the main html document.
General info
- Specification
- Interface
-
Event
- Bubbles
-
Yes
- Cancelable
-
Yes (although specified as a simple event that isn't cancelable)
- Target
-
Document
- Default Action
-
None.
屬性
| Property | Type | Description |
|---|---|---|
target Read only |
EventTarget |
The event target (the topmost target in the DOM tree). |
type Read only |
DOMString |
The type of event. |
bubbles Read only |
Boolean |
Whether the event normally bubbles or not. |
cancelable Read only |
Boolean |
Whether the event is cancellable or not. |
規範
| Specification |
|---|
| HTML Standard # event-domcontentloaded |
瀏覽器相容性
BCD tables only load in the browser