如何使用SimpleXML对XML feed进行排序

Question

我已经开始使用simplexml函数，它似乎比我之前尝试使用的其他解析器工作得更好。我已经到了需要按transmissiondate对项目进行排序的阶段-我尝试使用uasort，但没有对项目的顺序进行任何更改。

此外，有时一个节目在同一天播放不止一次-按videoID排序会不会更容易一些？

对象的外观如下所示：

[0] => SimpleXMLElement Object
    (
        [VideoID] => 108059
        [Genre] => Music
        [ProgrammeName] => MTV
        [OriginalAiringDate] => 2009-11-10T19:22:24
        [TransmissionDate] => 2009-11-10T19:22:24
   )
[1] => SimpleXMLElement Object
    (
        [VideoID] => 108395
        [ExpiryDate] => 2009-12-12T23:59:59
        [DateCreated] => 2009-11-12T13:28:54
        [Genre] => Music
        [ProgrammeName] => MTV
        [OriginalAiringDate] => 2009-11-12T19:22:32
        [TransmissionDate] => 2009-11-12T19:22:32
 )

$xml = simplexml_load_file("data.xml");
$count = 0;
$sortItem = 0;
$dateformat = "D j M, g:ia";
$sortArray = array();
foreach($xml->CatchUp as $item){
$sortArray[$count][TransmissionDate] = $item;
if($count < 4){
print "<p>Programme Name:<strong> "  . $item->ProgrammeName. "</strong></p>";
print "<p>Date Shown:<strong> "  . date($dateformat, strtotime($item->TransmissionDate)). "</strong></p>";
print "<p>Description:<strong> " . trunc($item->ShortSynopsis,30, " ")."</strong></p>";
print "<p><a href='". $item->VideoID. "'>". $item->VideoID."</a></p>";
         $count++;
  }
}

}

排序($sortArray)；

Answer 1

我认为有两种方法可以做到这点。第一种方法是创建一个包含TransmissionDate值的数组，然后创建另一个包含相应节点的数组，然后使用array_multisort()。这有点单调乏味，所以我要做的是:下载SimpleDOM并使用sortedXPath()

include 'SimpleDOM.php';

$xml = simpledom_load_file("data.xml");
$dateformat = "D j M, g:ia";

foreach($xml->sortedXPath('CatchUp[ProgrammeName="MTV"]', 'TransmissionDate') as $i => $item)
{
    if ($i == 4)
    {
        // I assume you only want the first 4
        break;
    }
    print "<p>Programme Name:<strong> "  . $item->ProgrammeName. "</strong></p>";
    print "<p>Date Shown:<strong> "  . date($dateformat, strtotime($item->TransmissionDate)). "</strong></p>";
    print "<p>Description:<strong> " . trunc($item->ShortSynopsis,30, " ")."</strong></p>";
    print "<p><a href='". $item->VideoID. "'>". $item->VideoID."</a></p>";
}

Answer 2

尝试在从SimpleXMLElement对象中提取数据时使用强制转换

使用视频id：$sortArray[$count][VideoID] = (int)$item;