add isbnLookup to lookup books by ISBN-10 or ISBN-13

EANSearch.php

@@ -41,6 +41,17 @@ function barcodeSearch($ean, $lang = 1) {
 		return $response->product;
 	}
 
+	// only return the book name
+	function isbnLookup($isbn) {
+		$xml = file_get_contents("https://api.ean-search.org/api?"
+			. "op=barcode-lookup&token=$this->accessToken&isbn=$isbn", false, $this->ctx);
+		if ($xml === FALSE) {
+			return '';
+		}
+		$response = new SimpleXMLElement($xml);
+		return $response->product->name;
+	}
+
 	function barcodePrefixSearch($prefix, $page = 0) {
 		$xml = file_get_contents("https://api.ean-search.org/api?"
 			. "op=barcode-prefix-search&token=$this->accessToken&prefix=$prefix&page=$page", false, $this->ctx);

README.md

@@ -24,6 +24,10 @@ echo "$ean is $name\n";
 $product = $eanSearch->barcodeSearch($ean, 1);
 echo "$ean is $product->name from category $product->categoryName issued in $product->issuingCountry\n";
 
+$isbn = '1119578884';
+$title = $eanSearch->isbnLookup($isbn);
+echo "$isbn is $title\n";
+
 $ok = $eanSearch->verifyChecksum($ean);
 echo "$ean is " . ($ok ? 'valid' : 'invalid') . "\n";