Planning The Application

Planning The Application
应用规划

英文原文：http://emberjs.com/guides/getting-started/planning-the-application

应用规划

TodoMVC, despite its small size, contains most of the behaviors typical in modern single page applications. Before continuing, take a moment to understand how TodoMVC works from the user’s perspective.

尽管TodoMVC是一个小应用，但是它涵盖了现今典型单页面应用（single page applications）几乎所有的行为。在继续之前，先从用户视角了解一下TodoMVC是怎样工作的。

TodoMVC has the following main features:

TodoMVC包含了以下几个主要功能：

Planning The Application - 图1

It displays a list of todos for a user to see. This list will grow and shrink as the user adds and removes todos.
为用户提供一个todos的列表，并且会随着用户添加或移除todos进行增长与缩减。
It accepts text in an <input> for entry of new todos. Hitting the <enter> key creates the new item and displays it in the list below.
从一个 <input> 框接收文本作为新建todos的入口，当点击 <enter> 键时，创建一项，并在列表下方显示。
It provides a checkbox to toggle between complete and incomplete states for each todo. New todos start as incomplete.
为每一个todo提供一个 checkbox 用于切换完成与未完成状态。新建的todo默认为未完成状态。
It displays the number of incomplete todos and keeps this count updated as new todos are added and existing todos are completed.
显示所有未完成的todos的数量，并在添加新todos和现有todos完成时，动态改变显示的值。
It provides links for the user to navigate between lists showing all, incomplete, and completed todos.
提供导航链接，使用户能切换显示全部（all）、未完成（incomplete）与完成（completed）的todos。
It provides a button to remove all completed todos and informs the user of the number of completed todos. This button will not be visible if there are no completed todos.
提供一个按钮用于提示用户当前已完成的todos数目，并在点击时移除所有已完成的todos。当无已完成todos时，此按钮不显示。
It provides a button to remove a single specific todo. This button displays as a user hovers over a todo and takes the form of a red X.
为每一个todo提供一个删除按钮，这个按钮显示为一个红色的X，并只在用户鼠标移动到这个todo上时显示。
It provides a checkbox to toggle all existing todos between complete and incomplete states. Further, when all todos are completed this checkbox becomes checked without user interaction.
提供一个 checkbox 用于切换列表中所有的todos的完成与未完成状态。而且，当所有的todos状态为完成时，它自动变为勾选状态。
It allows a user to double click to show a textfield for editing a single todo. Hitting the <enter> key or moving focus outside of this textfield will persist the changed text.
允许用户双击某一个todo，显示一个 textfield 用于修改这个todo。点击 <enter> 键或者当鼠标焦点从这个 textfield 移除时，持久化更改的内容。
It retains a user’s todos between application loads by using the browser’s localstorage mechanism.
使用 本地存储(localstorage) 机制保存用户的todos列表，在应用程序启动时重新加载。

You can interact with a completed version of the application by visiting the TodoMVC site.

你可以通过访问TodoMVC站点来体验一下完整的版本。