在使用PHP處理HTML時不時發生致命錯誤簡單的HTML DOM解析器

Question

我從使用PHP簡單的HTML DOM解析器的目錄號碼提取一些來自宜家網站的元數據。

號30275861和其他我正確的測試工作，併爲因此給該鏈接（$ PRODUKT變量）數十一些數據http://www.ikea.com/pl/pl/catalog/products/30275861/?query=30275861（如果鏈接粘貼到瀏覽器，它給出了卡拉克斯系統傢俱頁）

給數69136138 - 鏈接的結果（$ PRODUKT變量）http://www.ikea.com/pl/pl/catalog/products/S69136138/?query=69136138如果粘貼到瀏覽器（無敵電視傢俱）的作品給出了錯誤：

致命錯誤：調用一個成員函數find（）方法上，在大多數作品布爾

代碼案例如下所示：

<?php 

include('simple_html_dom.php'); 
function clean($string) { 
$string = str_replace(',', '.', $string); 
return preg_replace('/[^A-Za-z0-9\-.]/', '', $string); 
} 

if(isset($_POST['produkt_id'])){ 

$produkt_id=str_replace('.', '', $_POST['produkt_id']); 

    $url="http://www.ikea.com/pl/pl/search/?query=".$produkt_id; 
    $ch = curl_init(); 
    curl_setopt($ch, CURLOPT_URL, $url); 
    curl_setopt($ch, CURLOPT_HEADER, true); 
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true); // Must be set to true so that PHP follows any "Location:" header 
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); 

    $a = curl_exec($ch); // $a will contain all headers 

    $url = curl_getinfo($ch, CURLINFO_EFFECTIVE_URL); // Return the last effective URL 
    $produkt=(string)$url; 

$html = file_get_html($produkt); 

echo $produkt_id; 
echo "<br>"; 
echo $produkt; 

foreach($html->find('meta[name=partnumber]') as $e) echo $kod=$e->content; 
foreach($html->find('link[rel=image_src"]') as $e) echo $obrazek=$e->href;  
foreach($html->find('meta[name=title]') as $e) echo $nazwa=$e->content; 
foreach($html->find('meta[name=price]') as $e) echo $cena=floatval(clean($e->content)); 
?> 

Answer 1

爲什麼不試試你的包裹循環foreach在條件語句，這樣，如果$html既不是空也不是空的循環將只運行？

<?php 

     // ... SOME CODE ABOVE    
     $html = file_get_html($produkt); 

     /* WHY NOT (AT THIS POINT) TRY TO INSPECT THE CONTENT OF $html? WITH VAR_DUMP?*/ 
     var_dump($html);  //<== JUST TO SEE THE DATA CONTENT... 

     // ONLY RUN FOR LOOPS (ECHOING OUT SOME DATA) 
     // IF AND ONLY IF $html HAS SOME CONTENT  
     if($html && !empty($html)){ 
      echo $produkt_id; //<== MAKES SENSE TO ECHO THIS ONLY IF $html HAS DATA 
      echo "<br>";  //<== MAKES SENSE TO ECHO THIS ONLY IF $html HAS DATA 
      echo $produkt;  //<== MAKES SENSE TO ECHO THIS ONLY IF $html HAS DATA 

      foreach($html->find('meta[name=partnumber]') as $e){ 
       echo $kod=$e->content; 
      } 
      foreach($html->find('link[rel=image_src"]') as $e){ 
       echo $obrazek=$e->href; 
      } 
      foreach($html->find('meta[name=title]') as $e){ 
       echo $nazwa=$e->content; 
      } 
      foreach($html->find('meta[name= price]') as $e){ 
       echo $cena=floatval(clean($e->content)); 
      } 
     }