+
+ /**
+ * Gets the first child element with the given tag
+ *
+ * @param DOMElement $element element to pick at
+ * @param string $tag tag to look for
+ * @param string $namespace Namespace to look under
+ *
+ * @return DOMElement found element or null
+ */
+
+ static function child($element, $tag, $namespace=self::ATOM)
+ {
+ $els = $element->getElementsByTagnameNS($namespace, $tag);
+
+ if (empty($els) || $els->length == 0) {
+ return null;
+ } else {
+ return $els->item(0);
+ }
+ }
+
+ /**
+ * Grab the text content of a DOM element child of the current element
+ *
+ * @param DOMElement $element Element whose children we examine
+ * @param string $tag Tag to look up
+ * @param string $namespace Namespace to use, defaults to Atom
+ *
+ * @return string content of the child
+ */
+
+ static function childContent($element, $tag, $namespace=self::ATOM)
+ {
+ $el = self::child($element, $tag, $namespace);
+
+ if (empty($el)) {
+ return null;
+ } else {
+ return $el->textContent;
+ }
+ }