Example: Tree: Parse an XML-File
<?xml version="1.0" encoding="utf-8"?>
<books>
<book id="1">
<title>The Royal Game</title>
<author>Stefan Zweig</author>
</book>
<book id="2">
<title>The Stoker</title>
<author>Franz Kafka</author>
</book>
</books>
public static void print_simple (Xml.Node* node, string node_name) {
assert (node->name == node_name);
for (Xml.Node* iter = node->children; iter != null; iter = iter->next) {
if (iter->type == Xml.ElementType.TEXT_NODE) {
print (" - %s\n", iter->get_content ());
} else {
print ("Unexpected element %s\n", iter->name);
}
}
}
public static void print_book (Xml.Node* node) {
assert (node->name == "book");
print (" * Book:\n");
string? id = node->get_prop ("id");
if (id != null) {
print (" - %s\n", id);
} else {
print ("Expected: <book id=...\n");
}
for (Xml.Node* iter = node->children; iter != null; iter = iter->next) {
if (iter->type == Xml.ElementType.ELEMENT_NODE) {
switch (iter->name) {
case "title":
print_simple (iter, "title");
break;
case "author":
print_simple (iter, "author");
break;
default:
print ("Unexpected element %s\n", iter->name);
break;
}
}
}
}
public static void print_books (Xml.Node* node) {
assert (node->name == "books");
print ("Books:\n");
for (Xml.Node* iter = node->children; iter != null; iter = iter->next) {
if (iter->type == Xml.ElementType.ELEMENT_NODE) {
if (iter->name == "book") {
print_book (iter);
} else {
print ("Unexpected element %s\n", iter->name);
}
}
}
}
public static int main (string[] args) {
// Parse the document from path
Xml.Doc* doc = Xml.Parser.parse_file ("books.xml");
if (doc == null) {
print ("File 'books.xml' not found or permissions missing\n");
return 0;
}
Xml.Node* root = doc->get_root_element ();
if (root == null) {
print ("WANTED! root\n");
delete doc;
return 0;
}
if (root->name == "books") {
print_books (root);
} else {
print ("Unexpected element %s\n", root->name);
}
delete doc;
return 0;
}
valac --pkg libxml-2.0 parser-dom.vala
See:
