Question

我正在使用Met Office RSS Feed：

$metourl = "http://www.metoffice.gov.uk/public/data/PWSCache/WarningsRSS/Region/UK";
$metoxml = simplexml_load_file($metourl);
$count = $metoxml->channel->item;

我可以很容易地确定是否有任何“天气警告”（在这种情况下）：

if($count && $count->count() >= 1){

如果可能，我想要做的是计算在

下发生'YELLOW'或'RED'次警告的次数

$metoxml->channel->item->warningLevel

所以我可以回应那个？

E.g。 "There are x yellow and x red warnings."。

谢谢！

Answer 1

您可以使用xpath方法：

$metourl = "http://www.metoffice.gov.uk/public/data/PWSCache/WarningsRSS/Region/UK";
$metoxml = simplexml_load_file($metourl);
$metoxml->registerXpathNamespace('metadata',
  'http://metoffice.gov.uk/nswws/module/metadata/1.0');
$wl = $metoxml->xpath('//channel/item/metadata:warningLevel');

$counters = [ 'YELLOW' => 0, 'RED' => 0 ];

foreach ($wl as $e) {
  $str = trim((string)$e);
  if ($str === 'YELLOW')
    $counters['YELLOW']++;
  elseif ($str === 'RED')
    $counters['RED']++;
}

printf('There are %d yellow and %d red warnings.',
  $counters['YELLOW'], $counters['RED']);

示例输出

There are 14 yellow and 0 red warnings.

PHP：计算RSS提要中显示的特定值的次数

1 个答案: