PHP - 方法链 - 最佳实践？

Question

我需要一种不是根据URL生成面包屑导航的方法。

我的想法是创建一个名为“Breadcrumbs”的类，其作用如下：

$breadcrumbs = new BreadCrumb('<<')->crumb('www.google.com', 'Google')->crumb('www.youtube.com', 'Youtube');

这将生成一个数组，并随着每个方法链的执行，将内容添加到数组中，最终形成一个数组，我可以将其转换为URL结构。

我尝试了以下方法：

class Breadcrumbs {

    public $del; 
    public $breadcrumbs;

    public function __construct($del)
    {
        $this->breadcrumbs = array();
        $this->del = $del;  

    }

    public function crumb($uri, $name)
    {
         $this->breadcrumbs[] = array($uri => $name);
    }
}

然而，这并不能提供准确的结果，并且在尝试按照我的计划进行结构时会出现“unexpected '->''”。

你有任何想法我做错了哪里吗？

- Phorce

Answer 1

1. To do method chaining, you need to return an object from your method call. Typically you'll want:

   return $this;  // in function crumb()
   

2. The correct syntax to instantiate an object and immediately call a method on it is:

   (new BreadCrumb('<<'))->crumb(..)
   

   Without the extra parentheses it's ambiguous to PHP what you want to do.

3. Aside: you don't need to initialise your array inside the constructor, you can do that while declaring the array:

   public $breadcrumbs = array();
   

4. Aside: this is pretty inefficient:

   .. = array($uri => $name)
   

   You'll have a hard time getting that $uri key back out of the array, which makes your code unnecessarily complicated. You should simply do:

   $this->breadcrumbs[$uri] = $name;
   

   Alternatively, if your URIs aren't guaranteed to be unique, use a structure that's easier to work with later:

   $this->breadcrumbs[] = array($uri, $name);  // $arr[0] is the URI, $arr[1] the name
   

- deceze

---

+1。但请注意，第二点（对象解引用）需要 PHP 5.4 或更高版本。你现在应该使用 5.4+，但如果你没有的话，这是另一个升级的好理由。 - Simba

Answer 2

为了能够进行方法链接，您需要从crumb返回$this。

public function crumb($uri, $name)
{
     $this->breadcrumbs[] = array($uri => $name);
     return $this;
}

- jeoj