Ajax Patterns 讀書筆記 --3

程式設計模式 (25)

Programming Patterns (25) Web Services

• RESTful Service Expose web services according to RESTful principles.
• RPC Service（遠端程式調用） Expose web services as Remote Procedural Calls (RPCs).
• HTML Response（直接生成HTML代碼片斷傳回） Have the server generate HTML snippets to be displayed in the browser.
• Semantic Response（以特定語義的資料封裝方式傳回） Have the server respond with abstract, semantic, data.
• Plain-Text Message （Text格式傳遞）Pass simple messages between server and browser in plain-text format.
• XML Message （XML格式傳遞）Pass messages between server and browser in XML format.
• JSON Message Pass messages between server and browser in Javascript Object Notation (JSON) format.

浏覽器 - 伺服器對話

Browser-Server Dialogue

• Call Tracking Accommodate busy user behaviour by allocating a new XMLHtpRequest object for each request. See Richard Schwartz's blog entry.Note: Pending some rewrite to take into account request-locking etc.
• Distributed Events Keep objects synchronised with an event mechanism.
• On-Demand Javascript （立即響應JS）Download Javascript as and when required, instead of downloading it all on page load.

DOM Population

• XML Data Island（XML資料島） Retain XML responses as "XML Data Islands", nodes within the HTML DOM.
• Browser-Side XSLT（浏覽器端XSLT） Apply XSLT to convert XML Messages into XHTML.
• Browser-Side Templating（浏覽器端模闆） Produce browser-side templates and call on a suitable browser-side framework to render them as HTML.

性能優化

Performance Optimisation

• Fat Client （建立富用戶端）Create a rich, browser-based, client by peforming remote calls only when there is no way to achieve the same effect in the browser.
• Browser-Side Cache （浏覽器端緩存）Maintain a local cache of information.
• Guesstimate（估計值替代伺服器端的真實資料讀取） Instead of grabbing real data from the server, make a guesstimate that's good enough for most user's needs. ITunes Download Counter, GMail Storage Counter.
• Submission Throttling（送出調節） Instead of submitting upon each Javascript event, retain the data in a local buffer and upload it periodically.
• Explicit Submission（顯示送出） Instead of submitting upon each Javascript event, require the user to explicitly request it, e.g. submit upon clicking a button.
• Multi-Stage Download （頁面分級下載下傳）Quickly download the page structure with a standard request, then populate it with further requests.
• Predictive Fetch（資料預取） Anticipate likely user actions and pre-load the required data.

擴充

Extension

• Cross-Domain Proxy （跨域代理）Allow the browser to communicate with other domains by server-based mediation.
• Richer Plugin（更“富”的插件） Make your application "more Ajax than Ajax" with a Richer Plugin.

代碼産生與重用

Code Generation and Reuse

• Ajax Stub （樁）Use an "Ajax Stub" framework which allows browser scripts to directly invoke server-side operations, without having to worry about the details of XMLHttpRequest and HTTP transfer.
• Server-Side Code Generation（服務端的代碼生成） Automatically generate HTML and Javascript from server-side code.
• Cross-Browser Component （跨浏覽器元件）Create cross-browser components, allowing programmers to reuse them without regard for browser compatibility.

待續 --3