PHP设计模式 迭代器模式 - tianxintian22

迭代器模式，在不需要了解内部实现的前提下，遍历一个聚合对象的内部元素。相比于传统的编程模式，迭代器模式可以隐藏遍历元素所需要的操作。

AllHacl.php

<?<span style="color: #000000;">php

namespace Baobab;


</span><span style="color: #0000ff;">class</span> AllHacl <span style="color: #0000ff;">implements</span><span style="color: #000000;"> \iterator{

    </span><span style="color: #0000ff;">protected</span> <span style="color: #800080;">$ids</span><span style="color: #000000;">;</span><span style="color: #0000ff;">protected</span> <span style="color: #800080;">$index</span>;<span style="color: #008000;">//</span><span style="color: #008000;">当前位置</span>
    <span style="color: #0000ff;">function</span><span style="color: #000000;"> __construct(){
        </span><span style="color: #800080;">$db</span> = Factory::getDatabase('ha_cl'<span style="color: #000000;">);
        </span><span style="color: #800080;">$result</span> = <span style="color: #800080;">$db</span>->query('select ID from ha_cl'<span style="color: #000000;">);
        </span><span style="color: #800080;">$this</span>->ids = <span style="color: #800080;">$result</span>-><span style="color: #000000;">fetch_all(MYSQLI_ASSOC);
    }<br>
　　<span style="color: #008000;">/*<span style="color: #008000;">*<br>　　 * 返回当前元素<br>　　 <span style="color: #008000;">*/</span></span></span>
   </span><span style="color: #0000ff;">function</span> <span style="color: #008080;">current</span><span style="color: #000000;">(){
        </span><span style="color: #800080;">$id</span> = <span style="color: #800080;">$this</span>->ids[<span style="color: #800080;">$this</span>->index]['ID'<span style="color: #000000;">];
        </span><span style="color: #0000ff;">return</span> Factory::getHacl(<span style="color: #800080;">$id</span><span style="color: #000000;">);
   }<br>
　　<span style="color: #000000;"><span style="color: #008000;">/*<span style="color: #008000;">*<br>　　 * 向前移动到下一个元素<br>　　 <span style="color: #008000;">*/</span></span></span></span> 
    </span><span style="color: #0000ff;">function</span> <span style="color: #008080;">next</span><span style="color: #000000;">(){
        </span><span style="color: #800080;">$this</span>->index ++<span style="color: #000000;">;
    }

    </span><span style="color: #008000;">/*</span><span style="color: #008000;">*
     * 返回到迭代器的第一个元素
     </span><span style="color: #008000;">*/</span>
    <span style="color: #0000ff;">function</span> <span style="color: #008080;">rewind</span><span style="color: #000000;">(){
        </span><span style="color: #800080;">$this</span>->index = 0<span style="color: #000000;">;
    }

    </span><span style="color: #008000;">/*</span><span style="color: #008000;">*
     * 查询当前位置是否有数据
     </span><span style="color: #008000;">*/</span>
    <span style="color: #0000ff;">function</span><span style="color: #000000;"> valid(){
        </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$this</span>->index - <span style="color: #008080;">count</span>(<span style="color: #800080;">$this</span>-><span style="color: #000000;">ids);
    }<br>
　　<span style="color: #000000;"><span style="color: #008000;">/*<span style="color: #008000;">*<br>　　 * 返回当前元素的键<br>　　 <span style="color: #008000;">*/</span></span></span></span>
    </span><span style="color: #0000ff;">function</span> <span style="color: #008080;">key</span><span style="color: #000000;">(){
        </span><span style="color: #0000ff;">return</span> <span style="color: #800080;">$this</span>-><span style="color: #000000;">index;
    }
}</span>

index.php

<span style="color: #800080;">$hacls</span> = <span style="color: #0000ff;">new</span><span style="color: #000000;"> \Baobab\AllHacl();
</span><span style="color: #0000ff;">foreach</span>(<span style="color: #800080;">$hacls</span> <span style="color: #0000ff;">as</span> <span style="color: #800080;">$hacl</span><span style="color: #000000;">){
    </span><span style="color: #008080;">var_dump</span>(<span style="color: #800080;">$hacl</span>-><span style="color: #000000;">haclname);
}</span>

Hacl类相关内容参考数据对象映射模式。http://www.cnblogs.com/tianxintian22/p/5232016.html