From WorldCat Developers' Network

PHP Function for WorldCat API OpenSearch Requests

Description

Given OpenSearch parameter values and a valid OCLC web service key, formats a WorldCat API OpenSearch request URL, gets a request response, transforms the response into a PHP Array, and returns the array.

This function assumes the use of a PHP RSS parser, in this instance the MagpieRSS parser (http://magpierss.sourceforge.net/).

worldcat_opensearch( string $key, string $query, string $format, string $start, string $count, string $cformat);

Parameters

• $key = The WorldCat Search API key assigned by OCLC
• $query = Search query terms
• $format = rss or atom (default)
• $start = Starting record position
• $count = Maximum number of records per response (no more than 50)
• $cformat = The preferred citation format: apa, chicago, harvard, mla, or turabian

Return Values

This function returns null (for zero results and any request errors) or an array of one or more records, each record represented by an array with these values:

• title = The item title
• author = The author name, if any
• summary = A summary of the item, if available
• link = A link to the item in WorldCat.org
• content = An encoded HTML string representing the item in the specified citation format

Function Code

// Require MagpieRSS, change the path to its location on your server
// For more information on MagpieRSS: http://magpierss.sourceforge.net/
require_once('rss_fetch.inc');
	
function worldcat_opensearch($key,$query,$format,$start,$count,$cformat) {
	
	// declare array
	$r = null;
	
	// set counter
	$c = 0;

	// construct worldcat opensearch request
	$url = "http://www.worldcat.org/webservices/catalog/search/worldcat/";
	$url .= "opensearch?q=";
	$url .= urlencode($query);
	$url .= "&format=".$format;
	$url .= "&start=".$start;
	$url .= "&count=".$count;
	$url .= "&cformat=".$cformat;
	$url .= "&wskey=".$key;
	
	// fetch the OpenSearch result
	$rss = fetch_rss($url);
	
	// if there was a result
	if ($rss) {
		// for each item
		foreach ($rss->items as $item) {
			// get descriptive data
			$title = $item['title'];
			$author = $item['author_name'];
			if ($format == "rss") {
				$summary = $item['description'];
				$link = $item['link'];
				$content = $item['content']['encoded'];
			} else {
				$summary = $item['summary'];
				$link = $item['id'];
				$content = $item['atom_content'];
			}
			// add item values to an array
			$a=array("author"=>$author,"title"=>$title,"summary"=>$summary,"link"=>$link,"content"=>$content);
			// add the item to the result array
			$r[$c] = $a;
			// increment the result counter
			$c++;	  
		} // end foreach item
	} // end if rss
	echo "</ul>";	
	
	// return the result array
	return $r;
	
} // end worldcat_opensearch

Examples

To submit a request for the search terms stored in $query, with a response in the Atom publishing format, starting with record 1, showing a maximum of 5 records, and with citations in the MLA format (the API key is assumed to be stored in the $key variable, in this example):

if (strlen($query) > 0) {	
	$worldcat = worldcat_opensearch($key,$query,"atom","1","5","mla");
	if ($worldcat) {
		foreach ($worldcat as $r) {
			echo "Citation: ".$r["content"];	
			echo "Author: ".$r["author"]."<br/>";	
			echo "Title: ".$r["title"]."<br/>";	
			echo "Summary: ".$r["summary"]."<br/>";	
			echo "<a href=\"".$r["link"]."\" target=\"_blank\">Find in a library</a>";
			echo "<hr/>";
		}
	}
}