如果在rss feed中找不到图像的备用图片

Question

我有一个rss订阅源从本地新闻纸中获取最新的项目。我从一个致命的错误开始了这个工作日，因为他们发布了一篇没有封闭图片的新闻报道。我想要的是添加一个条件标签来显示默认图像，如果没有图像封闭。

我的代码是这样的：

<?php 
function read_rss($display=0,$url='') { 
$doc = new DOMDocument(); 
$doc->load($url); 
$itemArr = array(); 
foreach ($doc->getElementsByTagName('item') as $node) { 
    if ($display == 0) { 
     break; 
    } 
    $itemRSS = array (
     'title'  => $node->getElementsByTagName('title')->item(0)->nodeValue, 
     'description' => $node->getElementsByTagName('description')->item(0)->nodeValue, 
     'link'  => $node->getElementsByTagName('link')->item(0)->nodeValue, 
     'pubdate'  => $node->getElementsByTagName('pubDate')->item(0)->nodeValue, 
     'artikkelbilde' => $node->getElementsByTagName('enclosure')->item(0)->getAttribute('url') 
    ); 
    array_push($itemArr, $itemRSS); 
    $display--; 
} 
return $itemArr; 
} 
?> 
<div class="prl-span-12 prl-panel clearfix"> 
<h5 class="prl-block-title default"><a href="http://h-a.no">Lokale nyheter</a></h5> 
<div class="prl-grid prl-grid-divider"> 
<?php 
$items = read_rss(3, 'http://www.h-a.no/rss/rssfeed.aspx?subject1=1'); 
foreach ($items as $item) { 
echo '<div class="prl-span-4"><article class="prl-article"><a class="prl-thumbnail" href="' . $item['link'] . '" title="'.$item['title'].'"><span class="prl-overlay"><img src="'. $item['artikkelbilde'] .'" alt="'.$item['title'].'"><span class="prl-overlay-area o-ha"></span></span></a><h6 class="prl-article-title"><a href="' . $item['link'] . '" title="'.$item['title'].'">'.$item['title'].'</a></h6></article> 
    </div>';  
} 

我已经使用了一些在这里发现的条件码的尝试，但我仍然得到这个错误：

Fatal error: Call to a member function getAttribute() on null in /home/4/h/hamarradioen/www/wp-content/themes/presslayer-hr/inc/nyhetsfeed-hamar.php on line 18

Answer 1

您需要检查是否$node->getElementsByTagName('enclosure')->item(0)回报给你一些东西。例如：

foreach ($doc->getElementsByTagName('item') as $node) { 
    if ($display == 0) { 
     break; 
    } 

    $itemRSS = array (
      'title'  => $node->getElementsByTagName('title')->item(0)->nodeValue, 
      'description' => $node->getElementsByTagName('description')->item(0)->nodeValue, 
      'link'  => $node->getElementsByTagName('link')->item(0)->nodeValue, 
      'pubdate'  => $node->getElementsByTagName('pubDate')->item(0)->nodeValue, 
      'artikkelbilde' => false, 
     ); 
    $enc_node = $node->getElementsByTagName('enclosure')->item(0); 
    if (!empty($enc_node)) { 
     $itemRSS['artikkelbilde'] = $enc_node->getAttribute('url'); 
    } 

    array_push($itemArr, $itemRSS); 
    $display--; 
} 

稍后，您可以检查是否artikkelbilde没有空，你所需要的：

if ($item['artikkelbilde']) { 
    echo 'One thing'; 
} else { 
    echo 'Another thing'; 
} 

Answer 2

我现在这样做，似乎已经奏效：

<?php function read_rss($display=0,$url='') { 
$doc = new DOMDocument(); 
$doc->load($url); 
$itemArr = array(); 
foreach ($doc->getElementsByTagName('item') as $node) { 
    if ($display == 0) { 
     break; 
    } 
    $itemRSS = array (
     'title'  => $node->getElementsByTagName('title')->item(0)->nodeValue, 
     'description' => $node->getElementsByTagName('description')->item(0)->nodeValue, 
     'link'  => $node->getElementsByTagName('link')->item(0)->nodeValue, 
     'pubdate'  => $node->getElementsByTagName('pubDate')->item(0)->nodeValue, 
     'artikkelbilde' => false 
    ); 
$enc_node = $node->getElementsByTagName('enclosure')->item(0); 
if (!empty($enc_node)) { 
$itemRSS['artikkelbilde'] = $enc_node->getAttribute('url'); 
} 
    array_push($itemArr, $itemRSS); 
    $display--; 
} 
return $itemArr; 
} 
?> 
<div class="prl-span-12 prl-panel clearfix"> 
<h5 class="prl-block-title default"><a href="http://h-a.no">Lokale nyheter</a></h5> 
<div class="prl-grid prl-grid-divider"> 
<?php 
$items = read_rss(3, 'http://www.h-a.no/rss/rssfeed.aspx?subject1=1'); 
foreach ($items as $item) { 
$sakbilde = $item['artikkelbilde']; 
if ($item['artikkelbilde']) { 
$sakbilde = $item['artikkelbilde']; 
} 
else { 
$sakbilde = 'http://hamarradioen.no/wp-content/uploads/2017/03/hamararbeiderblad900x600.jpg'; } 

echo '<div class="prl-span-4"><article class="prl-article"><a class="prl-thumbnail" href="' . $item['link'] . '" title="'.$item['title'].'"> 
<span class="prl-overlay"><img src="'. $sakbilde .'" alt="'.$item['title'].'"><span class="prl-overlay-area o-ha"></span></span></a> <h6 class="prl-article-title"><a href="' . $item['link'] . '" title="'.$item['title'].'">'.$item['title'].'</a></h6></article> 
    </div>'; }