使用動態屬性變量不起作用的重寫屬性PHP 7.0

Question

當從PHP 5.6切換到7.0時。我需要根據這個腳本來做。我正在嘗試在wordpress中應用重寫規則，但遇到了一個奇怪的PHP問題。通過變量創建的Dinamic屬性在PHP 7.0中不起作用。

$rule = [ 'name' => 'profile', 
      'rule' => 'author_base', 
      'rewrite' => 'profile', 
      'position' => 'top', 
      'replace' => true, 
      'dynamic' => true 
     ]; 
global $wp_rewrite; 
global $wp; 
$wp->add_query_var($rule['name']); 
if(isset($rule['replace']) && $rule['replace']) { 
    var_dump($rule['rule']); // author_base 
    $wp_rewrite->$rule['rule']=$rule['rewrite']; // this doesn't work 
    $wp_rewrite->author_base=$rule['profile']; // this works 
    var_dump($wp_rewrite->$rule['rule']) // return null => BAD 
    var_dump($wp_rewrite->author_base); // returns 'author' => OK 
    // In PHP 5.6 Works both including $wp_rewrite->$rule['rule'] 
} else { 
    add_rewrite_rule($rule['rule'], $rule['rewrite'], $rule['position']); 
}  

Answer 1

這是php7的B.C之一。

現在將按照從左到右的順序嚴格評估對變量，屬性和方法的間接訪問，而不是以前的混合特例。

| Expression   | PHP 5 interpretation | PHP 7 interpretation | 
|---------------------|-----------------------|-----------------------| 
| $foo->$bar['baz']() | $foo->{$bar['baz']}() | ($foo->$bar)['baz']() | 

所以，改變

$wp_rewrite->$rule['rule']=$rule['rewrite']; 
var_dump($wp_rewrite->$rule['rule']); 

到

$wp_rewrite->{$rule['rule']}=$rule['rewrite']; 
var_dump($wp_rewrite->{$rule['rule']});