在類構造函數中設置會話變量時遇到麻煩

Question

我幾個月前才進入PHP，現在幾個星期一直在面向對象PHP。我認爲我做得很好。

我寫了一個表類，將查詢轉換爲一個表，分頁，排序等

這一切都相當不錯，除了一個小東西的工作，那就是我想要一個默認的$ _SESSION [」 TABLE_ORDERBY']變量在實例化Table類時得到設置。

我現在將它設置這樣的構造：

$_SESSION['TABLE_ORDERBY'] = $this->_arr_fetched_row_headers[1]; 

當我更換$這個 - > _ arr_fetched_row_headers [1]像 'NewsDate' 的字符串。它確實有效（我必須先開始一個新的會話）。

我該如何去使它能夠使用$ this - > _ arr_fetched_row_headers [1]自動設置會話變量？由processQuery（）方法中使用

$ arr_fetched_rows：

Array ([0] => Array ( 
[0] => NewsID [1] => NewsTitle [2] => NewsDate) 
[1] => Array ([0] => 1753 [1] => Test2 [2] => 2011-07-05 15:26:38) 
[2] => Array ([0] => 1754 [1] => Test3 [2] => 2011-07-05 15:26:51) 
[3] => Array ([0] => 1755 [1] => Test4 [2] => 2011-07-05 15:26:51) 
[4] => Array ([0] => 1756 [1] => Test5 [2] => 2011-07-19 08:44:13) 
[5] => Array ([0] => 1758 [1] => Test8 [2] => 2011-07-19 08:44:38) 
etc...... 
[count_all_rows] => 14) 

Table.class.php（僅示出了幾個方法）

<?php 
class Table 
{ 
    /* construct */ 
    public function __construct() 
    { 
     // initialise max_result 
     if(isset($_POST['maxresult'])) { 
      $_SESSION['TABLE_MAXRESULT'] = $_POST['maxresult']; 
     } 
     if(!isset($_SESSION['TABLE_MAXRESULT'])) { 
      $_SESSION['TABLE_MAXRESULT'] = 5; 
     } 

     // initialise pagination 
     if(!isset($_SESSION['TABLE_FROM'])) { 
      $_SESSION['TABLE_FROM'] = 0; 
     } 
     if(isset($_GET['page'])) { 
      $_SESSION['TABLE_FROM'] = $_GET['page'] * $_SESSION['TABLE_MAXRESULT'] - $_SESSION['TABLE_MAXRESULT'];; 
     } 
     if(!isset($_GET['page'])) { 
      $_GET['page'] = 1; 
     } 

     // initialise sorting 
     if(isset($_GET['sort']) && $_GET['sort'] == 'asc' && isset($_GET['sortby'])) { 
      $_SESSION['TABLE_ORDERBY'] = $_GET['sortby']; 
      $_SESSION['TABLE_ORDER'] = 'ASC'; 
     } 
     if(isset($_GET['sort']) && $_GET['sort'] == 'desc' && isset($_GET['sortby'])) { 
      $_SESSION['TABLE_ORDERBY'] = $_GET['sortby']; 
      $_SESSION['TABLE_ORDER'] = 'DESC'; 
     } 
     if(!isset($_SESSION['TABLE_ORDERBY']) || !isset($_SESSION['TABLE_ORDER'])) { 
      $_SESSION['TABLE_ORDERBY'] = $this->_arr_fetched_row_headers[1]; 
      $_SESSION['TABLE_ORDER'] = 'DESC'; 
     } 

    } 

    public function processQuery($arr_fetched_rows) 
    { 
     // define the $this->_arr_fetched_rows property 
     $this->_arr_fetched_rows = $arr_fetched_rows; 

     // extract the row headers from $this->_arr_fetched_rows 
     $this->_arr_fetched_row_headers = $this->_arr_fetched_rows[0]; 

     // count the row headers in $this->_arr_fetched_row_headers 
     $this->_count_row_headers = count($this->_arr_fetched_row_headers); 

     // count the total amount of rows from $this->_arr_fetched_rows 
     $this->_count_all_rows = $this->_arr_fetched_rows['count_all_rows']; 

     // count keys in $this->_arr_fetched_rows, subtract by 2 because of row headers and count_all_rows 
     $this->_count_fetched_rows = count($this->_arr_fetched_rows) - 2; 

     // create a new array without the row headers and without count_all_rows 
     for($i = 1; $i <= $this->_count_fetched_rows; $i++) { 
      $this->_arr_sent_rows[] = $this->_arr_fetched_rows[$i]; 
     } 
    } 

    *** edited out other methods *** 

    // show table 
    public function showTable() 
    { 
     // return the built table 
     return $this->buildTable(); 
    } 
} 

的index.php

<?php 
require_once 'class/Session.class.php'; 
require_once 'class/Query.class.php'; 
require_once 'class/Table.class.php'; 

$session = new Session(); 
$query = new Query(); 
$table = new Table(); 

$result = $query->selectQuery("NewsID, NewsTitle, NewsDate", "tbl_news", "ORDER BY " . $_SESSION['TABLE_ORDERBY'] . " " . $_SESSION['TABLE_ORDER'] . " LIMIT " . $_SESSION['TABLE_FROM'] . ", " . $_SESSION['TABLE_MAXRESULT'] . " "); 

$table->processQuery($result); 
$table->renameHeaders('NieuwsID, Nieuwstitel, Publicatiedatum, Bewerk, Verwijder'); 
$table->showCheckEditDelete(true, true, true); 
$table->hideRowID(true); 
$table->enableSort(true); 
?> 
<?php echo $table->showTable(); ?> 

Answer 1

你的事件順序是：

$table = new Table(); 
... 
$table->processQuery($result); 

processQuery是設置_arr_fetched_row_headers的功能，但你已經嘗試過在表構造函數中使用它（new Table實際調用__construct功能。）

這是問題的一系列事件。