refactor: improve the XML parsing

crates/gpapi/src/utils/xml.rs

@@ -1,6 +1,17 @@
-use roxmltree::Document;
+use roxmltree::Node;
 
-pub(crate) fn get_child_text(doc: &Document, name: &str) -> Option<String> {
-  let node = doc.descendants().find(|n| n.has_tag_name(name))?;
-  node.text().map(|s| s.to_string())
+pub(crate) trait NodeExt<'a> {
+  fn find_child(&self, name: &str) -> Option<Node<'a, 'a>>;
+  fn child_text(&self, name: &str) -> Option<&'a str>;
+}
+
+impl<'a> NodeExt<'a> for Node<'a, 'a> {
+  fn find_child(&self, name: &str) -> Option<Node<'a, 'a>> {
+    self.children().find(|n| n.has_tag_name(name))
+  }
+
+  fn child_text(&self, name: &str) -> Option<&'a str> {
+    let node = self.find_child(name)?;
+    node.text()
+  }
 }