Ajax Patterns 读书笔记 --4

功能性和使用性模式（28）
Functionality and Usability Patterns (28)

All of these widget（器件） patterns will be familiar to end-use, having been available in desktop GUIs and some in non-AJAX DHTML too. They are included here to catalogue the interaction styles（交互类型） that are becoming common in AJAX applications and can benefit from XMLHttpRequest-driven interaction.

内容类
Content Widgets

• Drilldown To let the user locate an item within a hierarchy, provide a dynamic drilldown.
• Microcontent Compose the page of "Microcontent" blocks - small chunks of content that can be edited in-page.
• Microlink Provide Microlinks that open up new content on the existing page rather than loading a new page.
• Popup Support quick tasks and lookups with transient Popups, blocks of content that appear "in front of" the standard content.
• Portlet Introduce "Portlets" - isolated blocks of content with independent conversational state.

表单类
Form Widgets

• Live Command-Line In command-line interfaces, monitor the command being composed and dynamically modifying the interface to support the interaction.
• Live Form Validate and modify a form throughout the entire interaction, instead of waiting for an explicit submission.
• Live Search As the user refines their search query, continuously show all valid results.
• Data Grid Report on some data in a rich table, and support common querying functions.
• Progress Indicator Hint that processing is occurring.
• Rich Text Editor e.g. http://dojotoolkit.org/docs/rich_text.html
• Slider Provide a Slider to let the user choose a value within a range.
• Suggestion Suggest words or phrases which are likely to complete what the user's typing.

页面结构类
Page Architecture

• Drag-And-Drop（拖放） Provide a drag-and-drop mechanism to let users directly rearrange elements around the page.
• Sprite Augment the display with "sprites": small, flexible, blocks of content.
• Status Area Include a read-only status area to report on current and past activity.
• Virtual Workspace Provide a browser-side view into a server-side workspace, allowing users to navigate the entire workspace as if it were held locally.

可视化效果类
Visual Effects

• One-Second Spotlight When a page element undergoes a value change or some other significant event, dynamically manipulate its brightness for a second or so.Responded
• One-Second Mutation When a page element undergoes a value change or some other significant event, dynamically mutate its shape for a second or so.
• One-Second Motion Incrementally move an element from point-to-point, or temporarily displace it, to communicate an event has occurred.
• Highlight Highlight elements by rendering them in a consistent, attention-grabbing, format.

功能性
Functionality

• Periodic Refresh（周期性刷新） The browser refreshs volatile information by periodically polling the server.
• Lazy Registration（延后式注册提交） Accumulate bits of information about the user as they interact, with formal registration occurring later on.
• Direct Login （直接登录/认证）Authenticate the user with an XMLHttpRequest Call instead of form-based submission, hashing in the browser for improved security.
• Host-Proof Hosting （主机端验证）Server-side data is stored in encrypted form for increased security, with the browser descrypting it on the fly. （Server端存储的为加密后的数据，Browser端解码）
• Timeout （超时处理）Implement a timeout mechanism to track which clients are currently active.
• Heartbeat （心跳，周期性更新）Have the browser periodically upload heartbeat messages to indicate the application is still loaded in the browser and the user is still active.
• Unique URLs（唯一URL请求） Use a URL-based scheme or write distinct URLs whenever the input will cause a fresh new browser state, one that does not depend on previous interaction.

待续--4