如何从零开始教女同学进行PHP开发：写需求文档_PHP

背景：远在北京的高中女同学让我帮忙当她的实训“技术顾问”，实训要求个人独立开发一个web项目，她选择的开发语言是php。其实我又当了一次标题党，她虽然以前从来没用过PHP，但是却有一点点html、css、javascript基础（据说已经忘光了），有用过C和java写过东西。

项目描述：

题目——资源预定管理系统

功能需求——

1. 针对企事业单位开发一个资源预定管理系统

2. 针对不同类别的资源，例如会议室、汽车、仪器设备等，向员工提供预约使用的功能

3. 员工登录系统后，可以查看指定的资源当前的预定情况，可以预定指定时间段内空闲的资源。

4. 不同的资源需要根据情况设置不同开放时间，例如每天的8:00到18:00，用于智能在开发时间内进行预定

5. 不同的资源可以预定的最小时间单位是不同的，例如会议室按分钟进行预定，最短15分钟，汽车按小时预定，最短2个小时。

6. 系统遵循先到先得的原则进行预定。

7. 用户预定后，尚未使用前可以取消，取消后，其它用户可以继续预定

第一步：写需求文档

计算机专业的同学一般都上过软件工程这门课，自然知道做需求的重要性。就算没上过，有过工作经验的同志们也应该看过别人写的需求文档。如果把一个项目的完成比作造房子，那么需求就好比建筑设计图，如果设计的不好，那么造出来的房子也不会好看。虽然软件开发比建筑有更大的灵活性（起码房子不能动不动就回滚代码，撤销更改），但是需求要是做得不全面不严格，往往会极大地增加不必要的工作量和降低工作效率。

你想想，今天告诉你这样一个需求，你代码写了一半，过几天告诉你需求改了，之前的代码都没用了，你什么感觉？虽然需求变更是常有的事，但是一旦需求发生失控，对项目的影响往往是灾难性的。

幸好妹子之前做桌面软件课程设计的时候写过需求文档，不然要从头开始学怎么做需求还是一件蛮麻烦的事情。但如果刚入门的童鞋嫌麻烦不做需求是大大的不妥，且不论进入正式工作后要接触更为严格严谨的需求文档，哪怕只是应付学校里的课程设计，在软件规模足够大的情况下，做需求用一天的时间，起码可以使开发的时间缩短一个星期。

第二步：登录页面的举例

妹子写需求文档去了，那我也不能闲着。因为我之前只是稍微看过php的相关资料，并没有用过php写过一行代码，为了走在妹子前面，必须要提前学习妹子要用的东西。由于这个课程设计的项目有登录的功能，所以我打算用这个页面作为介绍php的第一个例子，并且往后还会就登录功能整个流程进行更加详尽的说明。

首先，我们看一个最简单的html登录页面，上代码！

<ol class="dp-xml">
<li class="alt"><span><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span> </span></span></span></li>
<li>
<span> </span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span> </span></span>
</li>
<li class="alt">
<span> </span><span class="tag"><span class="tag-name">meta</span><span> </span><span class="attribute">charset</span><span>=</span><span class="attribute-value">"gbk"</span><span class="tag">></span><span> </span></span>
</li>
<li>
<span> </span><span class="tag"><span class="tag-name">title</span><span class="tag">></span><span>用户登录界面</span><span class="tag"></span><span class="tag-name">title</span><span class="tag">></span><span> </span></span>
</li>
<li class="alt">
<span> </span><span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span> </span>
</li>
<li>
<span> </span><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span>
</li>
<li class="alt">
<span> </span><span class="tag"><span class="tag-name">form</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"login"</span><span> </span><span class="attribute">action</span><span>=</span><span class="attribute-value">"Controller.php"</span><span> </span><span class="attribute">method</span><span>=</span><span class="attribute-value">"post"</span><span> </span><span class="tag">></span><span>     </span></span>
</li>
<li>
<span> </span><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">class</span><span>=</span><span class="attribute-value">"tbl"</span><span class="tag">></span><span>用户名：</span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"text"</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"user_id"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span>      </span></span></span></span>
</li>
<li class="alt">
<span>     </span><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">class</span><span>=</span><span class="attribute-value">"tbl"</span><span class="tag">></span><span>密码：</span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"text"</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"user_password"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span></span>
</li>
<li>
<span>     </span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"submit"</span><span> </span><span class="attribute">value</span><span>=</span><span class="attribute-value">"登入系统"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span>
</li>
<li class="alt">
<span> </span><span class="tag"></span><span class="tag-name">form</span><span class="tag">></span><span> </span>
</li>
<li>
<span> </span><span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span> </span>
</li>
<li class="alt">
<span class="tag"></span><span class="tag-name">html</span><span class="tag">></span><span> </span>
</li>
</ol>

为了让大家不当极致的伸手党，我就不把页面截图上来了，大家自己复制代码用浏览器看看效果。为什么我要给妹子写这几行代码呢？主要是想让妹子重新熟悉一下html代码长什么样子，而且是为了下面让妹子知道php与html为什么混合在一起做铺垫。过了这么一会儿，大家应该已经看过上面那些代码的显示效果了吧。既然这样，请看下面加入php后的代码：

<ol class="dp-xml">
<li class="alt"><span><span class="tag"></span><span class="tag-name">php</span><span>         //php代码部分开始  </span></span></li>
<li>
<span>echo "</span><span class="tag"><span class="tag-name">html</span><span class="tag">></span><span>";  </span></span>
</li>
<li class="alt">
<span>echo "</span><span class="tag"><span class="tag-name">head</span><span class="tag">></span><span>";  </span></span>
</li>
<li>
<span>echo "</span><span class="tag"><span class="tag-name">meta</span><span> </span><span class="attribute">charset</span><span>=\"gbk\"</span><span class="tag">></span><span>";  </span></span>
</li>
<li class="alt">
<span>echo "</span><span class="tag"><span class="tag-name">title</span><span class="tag">></span><span>用户登录界面</span><span class="tag"></span><span class="tag-name">title</span><span class="tag">></span><span>";  </span></span>
</li>
<li>
<span class="tag">?></span><span class="comments"><!--  php代码部分结束--></span><span> </span>
</li>
<li class="alt">
<span class="tag"></span><span class="tag-name">head</span><span class="tag">></span><span> </span>
</li>
<li><span class="tag"><span class="tag-name">body</span><span class="tag">></span><span> </span></span></li>
<li class="alt"><span class="tag"><span class="tag-name">form</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"login"</span><span> </span><span class="attribute">action</span><span>=</span><span class="attribute-value">"Controller.php"</span><span> </span><span class="attribute">method</span><span>=</span><span class="attribute-value">"post"</span><span> </span><span class="tag">></span><span> </span></span></li>
<li>
<span>     </span><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">class</span><span>=</span><span class="attribute-value">"tbl"</span><span class="tag">></span><span>用户名：</span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"text"</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"user_id"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span>      </span></span></span></span>
</li>
<li class="alt">
<span>     </span><span class="tag"><span class="tag-name">td</span><span> </span><span class="attribute">class</span><span>=</span><span class="attribute-value">"tbl"</span><span class="tag">></span><span>密码：</span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=</span><span class="attribute-value">"text"</span><span> </span><span class="attribute">name</span><span>=</span><span class="attribute-value">"user_password"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span> </span></span></span></span>
</li>
<li>
<span class="tag"></span><span class="tag-name">php</span><span>      </span>
</li>
<li class="alt">
<span>echo "</span><span class="tag"><span class="tag-name">td</span><span class="tag">></span><span class="tag"><span class="tag-name">input</span><span> </span><span class="attribute">type</span><span>=\"submit\" </span><span class="attribute">value</span><span>=\"登入系统\"</span><span class="tag">></span><span class="tag"></span><span class="tag-name">td</span><span class="tag">></span><span>"  </span></span></span>
</li>
<li>
<span class="tag">?></span><span> </span>
</li>
<li class="alt">
<span class="tag"></span><span class="tag-name">form</span><span class="tag">></span><span> </span>
</li>
<li>
<span class="tag"></span><span class="tag-name">body</span><span class="tag">></span><span> </span>
</li>
<li class="alt">
<span class="tag"></span><span class="tag-name">html</span><span class="tag">></span><span> </span>
</li>
</ol>

这段代码主要让妹子了解这么几点：（1）php代码要用标签进行标识（2）如何使用echo语句进行输出html代码，另外关于要用对""中的"(双引号）用\（转义符）进行转义。（3）php代码是如何跟html代码进行混合的。

PS：完事开头难，第一篇文章就先写这么多。起点定的太高反而不好，容易把初学者搞迷糊了。多看作为例子的代码，自己动手改一改，写一写，感受一下。

原文链接：http://www.cnblogs.com/levenyes/archive/2013/09/04/3299146.html