瀏覽器上的 JavaScript snippet：bookmarklet
總結
A small software application stored as a bookmark in a web browser, which typically allows a user to interact with the currently loaded web page in some way.
Bookmarklets are browser bookmarks that execute JavaScript instead of opening a webpage.
bookmarklet 是一種點擊後會執行 JavaScript 而非開啟頁面的（特殊）書籤
近期的應用情境：點擊該 bookmarklet 後將 // eslint-disable-line 複製到剪貼簿中（因開發時有臨時、一次性的單行註解需求，但註解頻率沒有高到需要將整個專案的 eslint 設定改寫，故改為有需求時切回瀏覽器點擊 bookmarklet 取得單行註解）
筆記
技術背景
- Web browsers use URIs for the href attribute of the
<a>tag and for bookmarks. The URI scheme, such ashttp:,file:, orftp:, specifies the protocol and the format for the rest of the string. URI 本身的 scheme 旨在定義該字串屬於哪一種 protocol - Browsers also implement a prefix
javascript:that to a parser is just like any other URI. Internally, the browser sees that the specified protocol is javascript, treats the rest of the string as a JavaScript application which is then executed, and uses the resulting string as the new page. 而瀏覽器實作的javascript:前綴使得在此之後的字串被當作 JavaScript 來處理 - The executing script has access to the current page, which it may inspect and change. If the script returns an
undefinedtype (rather than, for example, a string), the browser will not load a new page, with the result that the script simply runs against the current page content. This permits changes such as in-place font size and color changes without a page reload. 放在書籤中的 JavaScript 執行完畢後如果回傳undefined的話，就不會載入新的頁面- 在 Chrome ver. 100.0.4896.88 (Official Build) (x86_64) 上測試的結果是，只有在回傳的資料型態是 string 的情況下會刷新畫面內容（該頁面的內容會被回傳的 string 直接取代掉）
- 在回傳的資料型態不是 string 時，頁面內容不會有任何更動
實作
將此內容複製到書籤的 URL 欄位中，存檔後點擊該書籤，即可複製註解內容 // eslint-disable-line