Retrieve info on a book from the National Diet Liberary

bookinfo.php

<?php

function check_tag($tag){
	if (array_key_exists($tag, $_GET) && $_GET[$tag] <> ""){
		$value = $_GET[$tag];
	} else {
		$value = "";
	}
	return $value;
}

class fetch_xml_as_array{
  public static function fetch($api_url, $param, $type = 'GET'){
    $data = http_build_query($param, '', '&');
    $header = array('Content-Type: application/x-www-form-urlencoded', 'Content-Length: '.strlen($data));
    $context = array('http' => array('method'  => $type, 'header'  => implode("\r\n", $header), 'content' => $data));
    $xml = file_get_contents($api_url, false, stream_context_create($context));
    if (false === $xml) return false;
    $xml2 = preg_replace("/<(\/*)(\w+):(\w+)/",'<${1}${2}_${3}',$xml);
    $name_space_replaced_xml = preg_replace("/<dc_identifier xsi:type=\"dcndl:ISBN\">(\d+)<\/dc_identifier>/",'<isbn>${1}</isbn>',$xml2);
    $parse_xml = simplexml_load_string($name_space_replaced_xml,'SimpleXMLElement', LIBXML_NOCDATA);
    if (false === $parse_xml) return false;
    return self::conv_to_array($parse_xml);
  }

  public static function conv_to_array($xmlobj){
    $arr = array();
    if (is_object($xmlobj)){
      $xmlobj = get_object_vars($xmlobj);
    } else {
      $xmlobj = $xmlobj;
    }

    foreach ($xmlobj as $key => $val) {
      if (is_object($xmlobj[$key])) {
        $arr[$key] = self::conv_to_array($val);
      } else if (is_array($val)) {
        foreach($val as $k => $v) {
          if (is_object($v) || is_array($v)) {
            $arr[$key][$k] = self::conv_to_array($v);
          } else {
            $arr[$key][$k] = $v;
          }
        }
      } else {
        $arr[$key] = $val;
      }
    }
    return $arr;
  }
}

function clear_author($s){
	$s = preg_replace('/\s+共著,*\s*$/','',$s);
	$s = preg_replace('/\s+共編,*\s*$/','',$s);
	$s = preg_replace('/\s+［共著］,*\s*$/','',$s);
	$s = preg_replace('/\s+［共編］,*\s*$/','',$s);
	$s = preg_replace('/\s+［著］,*\s*$/','',$s);
	$s = preg_replace('/\s+［編］,*\s*$/','',$s);
	$s = preg_replace('/\s+［訳］,*\s*$/','',$s);
	$s = preg_replace('/\s+[共著],*\s*$/','',$s);
	$s = preg_replace('/\s+[共編],*\s*$/','',$s);
	$s = preg_replace('/\s+\[著\],*\s*$/','',$s);
	$s = preg_replace('/\s+\[編\],*\s*$/','',$s);
	$s = preg_replace('/\s+\[訳\],*\s*$/','',$s);
	$s = preg_replace('/\s+著,*\s*$/','',$s);
	$s = preg_replace('/\s+編,*\s*$/','',$s);
	$s = preg_replace('/\s+訳,*\s*$/','',$s);
	$s = preg_replace('/\s+他,*\s*$/','',$s);
	$s = preg_replace('/\s+他著,*\s*$/','',$s);
	$s = preg_replace('/\s+他編,*\s*$/','',$s);
	$s = preg_replace('/\s+他訳,*\s*$/','',$s);
	$s = preg_replace('/\s*,.*$/','',$s);
	return $s;
}

function conv_date($s){
	return date("Y-m-d", strtotime($s));
}

function output_attribute($key, $item, $callback = ""){
	$r = "";
	if (array_key_exists($key, $item)){
		$r = $item{$key};
		if($callback <> ""){
			$r = call_user_func($callback, $r);
		}
	} 
	echo $r."\t";
}

function get_attributes($items){
	foreach($items as $key => $item){ 
		output_attribute("author", $item, 'clear_author'); //dc_creatorだと著者が複数の場合配列で返る
		output_attribute("title", $item);
		output_attribute("link", $item);
		output_attribute("isbn", $item);
		output_attribute("pubDate", $item, 'conv_date');
		echo "\n";
	}
}


//// 
//$_GET['isbn' ]='9784000069731';

date_default_timezone_set('Asia/Tokyo');
$tags = array('isbn', 'title', 'creator');
foreach($tags as $tag){
	$value = check_tag($tag);
	if ($value <> ""){
		break;
	}
}
if ($value <> ""){
	$parsed = fetch_xml_as_array::fetch('http://iss.ndl.go.jp/api/opensearch?', array($tag => $value), 'GET');
	$num_items = $parsed{"channel"}{"openSearch_totalResults"};
	if($num_items == 0){
	} else if($num_items == 1){
		get_attributes(array($parsed{"channel"}{"item"}));
	} else {
		get_attributes($parsed{"channel"}{"item"});
	}
}