缺少时间导致的 PHP SimpleXML 错误

Posted 2023-02-16

【中文标题】缺少时间导致的 PHP SimpleXML 错误

【英文标题】：PHP SimpleXML error caused by missing times

【发布时间】：2022-01-03 06:39:22

【问题描述】：

我有以下代码，它显示日历 XML 提要，但是，并非所有事件都有开始/结束时间。这会导致错误。我希望当一个事件没有开始和结束时间时，它会显示“全天”。

//load xml file
$sxml = simplexml_load_file($url) or die("Error: Cannot create object");

echo '<div class="calendar">';

#search for all event start dates
$starts = $sxml->xpath('//event/startdate');

#get the unique start dates of these event
$dates = array_unique($starts);



foreach($dates as $date)     
    echo "<li><h1>$date</h1></li>" ."\n";

   #search for all events taking place on each start date
    $expression = "//event/startdate[.='$date']";
    $events = $sxml->xpath($expression);

   #iterate through these events and find their description
    foreach ($events as $event)
        echo "\t" , "<li><div class='time'>$event->xpath('./following-sibling::starttime')[0] - $event->xpath('./following-sibling::endtime')[0]</div><div class='event'><b> $event->xpath('./following-sibling::description')[0]</b>  //  $event->xpath('./following-sibling::category')[0]</div></li>";
        echo "\n";
    
    echo "\n";

echo "</div>";

下面的示例 XML 文件：

<event>
<startdate>24/11/2021</startdate>
<alldayevent>true</alldayevent>
<description>Event 1</description>
<category>Main Events</category>
</event>
<event>
<startdate>24/11/2021</startdate>
<alldayevent>false</alldayevent>
<starttime>14:00</starttime>
<endtime>16:30</endtime>
<description>Event 2</description>
<category>Main Events</category>
</event>

预期输出：

如果事件有时间/alldayevent = true，则显示开始和结束时间，否则如果 alldayevent = true，则输出 'All Day'

【问题讨论】：

请编辑您的问题并添加一个有代表性的 xml 示例，其中包含和不包含开始/结束时间以及每种情况下的预期输出。

谢谢，问题已更新。

【参考方案1】：

我相信，如果我对您的理解正确，您正在寻找类似以下的内容。

像这样更改您的foreach：

foreach($dates as $date)      
   echo "<li><h1>$date</h1></li>" ."\n";
   $expression = "//event/startdate[.='$date']";
   $events = $sxml->xpath($expression) ;
   foreach ($events as $event)
       echo $event->xpath('.//following-sibling::description')[0]."\n";
       if (($event->xpath('.//following-sibling::alldayevent'))[0] == "true") 
           echo "\t" , "<li><div class='time'>All Day</div></li>" ."\n";
            else 
        $st = $event->xpath('.//following-sibling::starttime')[0];
        $et = $event->xpath('.//following-sibling::endtime')[0];
        echo "\t" , "<li><div class='starttime'>$st</div></li>" ."\n";
           echo "\t" , "<li><div class='endtime'>$et</div></li>" ."\n";
        

          

输出：

<li><h1>24/11/2021</h1></li>
Event 1
    <li><div class='time'>All Day</div></li>
Event 2
    <li><div class='starttime'>14:00</div></li>
    <li><div class='endtime'>16:30</div></li>