XPathをためす

こちら(XPath Syntax)を参考に．

  NSXMLDocument* document= [NSXMLNode document];
  [document setVersion:@"1.0"];
  [document setCharacterEncoding:@"ISO-8859-1"];
  
  NSXMLElement* bookstore= [NSXMLNode elementWithName:@"bookstore"];
  [document setRootElement:bookstore];
  {
   NSXMLElement* book= [NSXMLNode elementWithName:@"book"];
   [bookstore addChild:book];
   {
    NSXMLElement* title= [NSXMLNode elementWithName:@"title"];
    [book addChild:title];
    [title addAttribute:[NSXMLNode attributeWithName:@"lang" 
              stringValue:@"eng"]];
    [title addChild:[NSXMLNode textWithStringValue:@"Harry Potter"]];
   }
   {
    NSXMLElement* price= [NSXMLNode elementWithName:@"price"];
    [book addChild:price];
    [price addChild:[NSXMLNode textWithStringValue:@"29.99"]];
   }
  }
  {
   NSXMLElement* book= [NSXMLNode elementWithName:@"book"];
   [bookstore addChild:book];
   {
    NSXMLElement* title= [NSXMLNode elementWithName:@"title"];
    [book addChild:title];
    [title addAttribute:[NSXMLNode attributeWithName:@"lang" 
              stringValue:@"eng"]];
    [title addChild:[NSXMLNode textWithStringValue:@"Learning XML"]];
   }
   {
    NSXMLElement* price= [NSXMLNode elementWithName:@"price"];
    [book addChild:price];
    [price addChild:[NSXMLNode textWithStringValue:@"39.95"]];
   }
  }
  
  NSString* output= [document XMLStringWithOptions:(NSXMLNodePrettyPrint|NSXMLNodeCompactEmptyElement)];
  NSLog(@"%@", output);
  
  NSArray *nodes= [bookstore nodesForXPath:@"/bookstore/book[price>35.00]/title" error:NULL];
  NSLog(@"%d", [nodes count]);
  int i;
  for(i= 0;i<[nodes count];i++) {
   NSLog(@"%@", [[nodes objectAtIndex:i] XMLString]);
  }

結果

> <?xml version="1.0" encoding="ISO-8859-1"?>
<bookstore>
    <book>
        <title lang="eng">Harry Potter</title>
        <price>29.99</price>
    </book>
    <book>
        <title lang="eng">Learning XML</title>
        <price>39.95</price>
    </book>
</bookstore>
> 1
> <title lang="eng">Learning XML</title>