第十二天
起点：
1. 手把手教你做关键词匹配项目（搜索引擎）---- 第一天
回顾：
11.手把手教你做关键词匹配项目（搜索引擎）---- 第十一天
上回说到，关键词应用需求为：
通过淘宝API取到的宝贝标题以及宝贝属性，匹配出适合该宝贝的关键词.
初期考虑以下因素：
适合人群的匹配 :男装 （匹配出来的关键词不能有女） 女装（匹配出来的关键词不能有男） 情侣装（男女适用） 童装（？）
淘宝API取出的宝贝属性字段：
小帅帅想了很久，总算想出来了一个解决方案，方案如下：
<?<span>php
</span><span>class</span><span> SelectorItem {
</span><span>private</span> <span>$item</span><span>;
</span><span>public</span> <span>function</span> __construct(<span>$item</span><span>){
</span><span>$this</span>->item = <span>$item</span><span>;
}
</span><span>public</span> <span>function</span> __get(<span>$name</span><span>){
</span><span>if</span>(<span>isset</span>(<span>$this</span>->item-><span>$name</span><span>)){
</span><span>return</span> <span>$this</span>->item-><span>$name</span><span>;
}
</span><span>return</span> <span>null</span><span>;
}
</span><span>public</span> <span>static</span> <span>function</span> createFromApi(<span>$num_iid</span><span>){
</span><span>$client</span> = <span>new</span><span> TopClient();
</span><span>$client</span>->appkey = 'xx'<span>;
</span><span>$client</span>->secretKey = 'xx'<span>;
</span><span>$req</span> = <span>new</span><span> ItemGetRequest();
</span><span>$req</span>->setFields('props_name,property_alias,detail_url,cid,title'<span>);
</span><span>$req</span>->setNumIid(<span>$num_iid</span><span>);
</span><span>$resp</span> = <span>$client</span>->execute(<span>$req</span><span>);
</span><span>if</span>(<span>isset</span>(<span>$resp</span>-><span>code)){
</span><span>#</span><span> error handle</span>
<span>throw</span> <span>new</span> <span>Exception</span>(<span>$resp</span>->msg, <span>$resp</span>-><span>code);
}
</span><span>return</span> <span>new</span> self(<span>$resp</span>-><span>item);
}
}
</span><span>$selectorItem</span> = SelectorItem::createFromApi(<span>$_REQUEST</span>["num_iid"<span>]);
Logger</span>::trace(<span>$selectorItem</span>-><span>props_name);
</span><span>$blackCharList</span> = <span>array</span><span>();
</span><span>$coreCharList</span> = <span>array</span><span>();
</span><span>$matchTitle</span> = <span>$selectorItem</span>->title.<span>$selectorItem</span>-><span>props_name;
</span><span>if</span>(<span>preg_match</span>('/男装/', <span>$matchTitle</span><span>)){
</span><span>$coreCharList</span> = <span>array</span><span>(
</span>"男装"<span>
);
</span><span>$blackList</span> = <span>array</span><span>(
</span>"女"<span>
);
}</span><span>else</span> <span>if</span>(<span>preg_match</span>('/女装/', <span>$matchTitle</span><span>)){
</span><span>$coreCharList</span> = <span>array</span><span>(
</span>"女装"<span>
);
</span><span>$blackList</span> = <span>array</span><span>(
</span>"男"<span>
);
}</span><span>else</span> <span>if</span>(<span>preg_match</span>('/情侣装/', <span>$matchTitle</span><span>)){
</span><span>$coreCharList</span> = <span>array</span><span>(
</span>"情侣装",
"男装",
"女装"<span>
);
}</span><span>else</span> <span>if</span>(<span>preg_match</span>('/童装/',<span>$matchTitle</span><span>)){
</span><span>$coreCharList</span> = <span>array</span><span>(
</span>"童装",
"儿童装",
"女童装",
"男童装"<span>
);
}
</span><span>$where</span> = <span>array</span><span>();
</span><span>foreach</span>(<span>$coreCharList</span> <span>as</span> <span>$char</span><span>){
</span><span>$where</span>[] = " word LIKE '%<span>$char</span>%'"<span>;
}
</span><span>foreach</span>(<span>$blackCharList</span> <span>as</span> <span>$char</span><span>){
</span><span>$where</span>[] = " word NOT LIKE '%<span>$char</span>%'"<span>;
}
</span><span>if</span>(<span>count</span>(<span>$where</span>)>0<span>){
</span><span>$sql</span> = "SELECT * FROM keywords WHERE ".<span>implode</span>(' AND ',<span>$where</span><span>);
Logger</span>::trace(<span>$sql</span><span>);
</span><span>//</span><span>search database</span>
}小帅帅很高兴的把代码拿给于老大时，小帅帅被于老大批了，原因很简单：
1. 没有考虑未来变化因素
2. if 太多
小帅帅被批了，心里很不高兴，但还是不得不去请教于老大的高招。
于老大给了一个方向给他。
1. 学习设计模式消除过多的if，以及如何去解耦。
设计模式（Design pattern）是一套被反复使用、多数人知晓的、经过分类编目的、代码设计经验的总结。使用设计模式是为了可重用代码、让代码更容易被他人理解、保证代码可靠性。 毫无疑问，设计模式于己于他人于系统都是多赢的；设计模式使代码编制真正工程化；设计模式是软件工程的基石脉络，如同大厦的结构一样。[来自百度百科]
小帅帅只好去了解设计模式了。
附：
<span>SelectorItem 里面的 __get 函数，称为Magic Methods<br />如:</span>
$selectorItem->title 其实会调用 __get('title')<span><br /><br /></span>
