Question

我正在关注一本php书，并不了解一些功能。

具体来说，公共功能DisplayMenu（$ buttons）。我知道这会为菜单创建一个表格（主页，联系人等，并将它们分开）。这里的参数

 public function DisplayButton($width, $name, $url, $active = true)

$width = 100/count($buttons);
    Here is what I am not understanding. Im setting a variable called width to be 100/count ? lets say buttons are 4 so 100/4 25? What is the point of the 25? Also,

$this -> DisplayButton($width, $name, $url, !$this->IsURLCurrentPage($url));

我知道他们在屏幕上制作了什么，但没有理解这些功能的关键部分。有人可以散发一点光。

//变量声明

public $content;
  public $title = 'TLA Consulting Pty Ltd';
  public $keywords = 'TLA Consulting, Three Letter Abbreviation, 
                   some of my best friends are search engines';
  public $buttons = array( 'Home'     => 'home.php', 
                        'Contact'  => 'contact.php', 
                        'Services' => 'services.php', 
                        'Site Map' => 'map.php'
                      );

  // class Page's operations
  public function __set($name, $value)
  {
    $this->$name = $value;
  }

public function DisplayMenu($buttons)
  {

    echo "<table width='100%' bgcolor='red' cellpadding='3' 
                cellspacing='4'\n";
    echo "  <tr>\n";

    $width = 100/count($buttons);

    while (list($name, $url) = each($buttons))
    {

      $this -> DisplayButton($width, $name, $url, !$this->IsURLCurrentPage($url));
    }
    echo "  </tr>\n";
    echo "</table>\n";
  }


  {
    if ($active)
    {
      echo "<td width ='$width%'>
            <a href ='$url'>
            <img src ='s-logo' alt ='$name' border ='0' /></a>
            <a href ='$url'><span class='menu'>$name</span></a></td>";
    }  
    else
    {
      echo "<td width ='$width%'>
            <img src ='side-logo.gif'>
            <span class='test'>$name</span></td>";
    }  
  }





   public function IsURLCurrentPage($url)
  //#determines weather a url for the button points to the current page.
  // #the server[php_self,$url] returns a number if the string in $url is inside the superglobal variable $_server[pph]
  {
    if(strpos($_SERVER['PHP_SELF'], $url )==false)
    {
      return false;
    }
    else
    {
      return true;
    }
  }






public function DisplayButton($width, $name, $url, $active = true)
  //outputs a single menu button if button is to point to the page to are on, you display an inactive button
#I think width just gives the table cell a % value.  $name involves a setter function declared up top? ,
  {
    if ($active)
    {
      echo "<td width ='$width%'>
            <a href ='$url'>
            <img src ='s-logo' alt ='$name' border ='0' /></a>
            <a href ='$url'><span class='menu'>$name</span></a></td>";
    }  
    else
    {
      echo "<td width ='$width%'>
            <img src ='side-logo.gif'>
            <span class='test'>$name</span></td>";
    }  
  }

Answer 1

可能这会遗漏class声明，但我们继续......

下面是声明类属性的位置。

public $content;
public $title = 'TLA Consulting Pty Ltd';
public $keywords = 'TLA Consulting, Three Letter Abbreviation, 
               some of my best friends are search engines';
public $buttons = array( 'Home'     => 'home.php', 
                    'Contact'  => 'contact.php', 
                    'Services' => 'services.php', 
                    'Site Map' => 'map.php'
                  );

__set()是PHP的神奇方法。您可以稍后检查所有这些here。我们将关注__set()。这意味着每次在对象中设置属性时，它都会定义并设置此属性，即使您尚未在类中声明它。

// class Page's operations
public function __set($name, $value)
{
    $this->$name = $value;
}

接下来，我们有DisplayMenu，它会在屏幕上显示菜单。 $width表示每个按钮的宽度。因此，如果$buttons中有4个按钮，它将分割空间，在这种情况下为100％，因此，每个按钮占25％。

public function DisplayMenu($buttons)
{

    echo "<table width='100%' bgcolor='red' cellpadding='3' 
            cellspacing='4'\n";
    echo "  <tr>\n";

    $width = 100/count($buttons);

    while (list($name, $url) = each($buttons))
    {
        // This will render the button on screen.
        // Params:
        // 1 The width of the button.
        // 2 The name of the button.
        // 3 The url the button points to.
        // 4 Checks if the button url is the same url of the current page. 
        $this->DisplayButton($width, $name, $url, !$this->IsURLCurrentPage($url));
     }
     echo "  </tr>\n";
     echo "</table>\n";
}

IsURLCurrentPage方法检查作为参数传递的$url是否为当前URL并返回true或false。如果是当前页面则为True，否则为false。

public function IsURLCurrentPage($url)
{
    if (strpos($_SERVER['PHP_SELF'], $url )==false)
    {
        return false;
    }
    else
    {
        return true;
    }
}

最后，DisplayButton将呈现实际按钮。它们中的每一个都是单独渲染的。

public function DisplayButton($width, $name, $url, $active = true)
{
    // This will, in practice verify for you if 
    // the current page is the same of the button the user clicked. 
    // If it is, it will display the button without the link for that 
    // button, or with a disabled link. 
    // You'll notice it will show differently. Maybe 
    // also with some different color or style according to the CSS class.
    // Remember that $active is the result of the IsURLCurrentPage().

    if ($active)
    {
        echo "<td width ='$width%'>
              <a href ='$url'>
              <img src ='s-logo' alt ='$name' border ='0' /></a>
              <a href ='$url'><span class='menu'>$name</span></a></td>";
    }  
    else
    {
        echo "<td width ='$width%'>
              <img src ='side-logo.gif'>
              <span class='test'>$name</span></td>";
    }  
}

这三个功能如何协同工作？

1 个答案: