Version 1.0

First release

ISBN.class.php

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+<?php
+
+	/**
+	 *
+	 *
+	 * USAGE
+	 * $isbn = new ISBN('978-2-123-4567-8');
+	 *
+	 * $isbn->isValid(); // returns true if code is a valid ISBN
+	 * $isbn->format(); // returns a formatted ISBN (ISBN-10, ISBN-13, EAN)
+	 * $isbn->getErrors(); // returns validation errors
+	 *
+	 *
+	 *
+	 */
+
+	class ISBN
+	{
+
+		// ISBN range.xml file, get it here : https://www.isbn-international.org/range_file_generation
+		const ISBN_RANGES_FILE = 'range.xml';
+
+		// Error messages (for localization)
+		const ERROR_INVALID_CHARACTERS = 'Invalid characters in the code',
+			  ERROR_INVALID_LENGTH = 'Code is too short or too long',
+			  ERROR_INVALID_COUNTRY = 'Country code unknown';
+
+		private $_product, // GS1 Product Code (978 or 979 for books)
+				$_country, // Registrant group (country) code
+				$_publisher, // Registrant (publisher) Code
+				$_publication, // Publication code
+				$_checksum, // Checksum character
+				$_input, // Input code
+				$_isValid = true, // Is the code a valid ISBN
+				$_errors = array(), // Why is the code invalid
+				$_format = 'EAN', // Output format
+				$_prefixes, // XML ranges file prefixes
+				$_groups, // XML ranges file groups
+				$_agency; // ISBN Agency
+
+		public function __construct($code)
+		{
+			$this->_input = $code;
+
+			// Load ISBN ranges from XML file
+			$this->loadRanges(self::ISBN_RANGES_FILE);
+
+			// Remove hyphens and check characters
+			$code = $this->removeHyphens($code);
+
+			// Remove checksum and check length
+			$code = $this->removeChecksum($code);
+
+			// Remove (and set) product code
+			$code = $this->removeProductCode($code);
+
+			// Remove (and save) country code
+			$code = $this->removeCountryCode($code);
+
+			// Remove (and save) publisher code
+			$this->removePublisherCode($code);
+
+		}
+
+		/* Check methods */
+
+		/**
+		 * Check if ISBN is valid
+		 */
+		public function isValid()
+		{
+			return (bool) $this->_isValid;
+		}
+
+		/* Format methods */
+
+		/**
+		 * Format an ISBN according to specified format
+		 * @param string $format (ISBN-10, ISBN-13, EAN)
+		 */
+		public function format($format = 'EAN')
+		{
+			$this->calculateChecksum($format);
+
+			$A = $this->getProduct();
+			$B = $this->getCountry();
+			$C = $this->getPublisher();
+			$D = $this->getPublication();
+			$E = $this->getChecksum();
+
+			if($format == 'ISBN-10')
+			{
+				return $B.'-'.$C.'-'.$D.'-'.$E;
+			}
+			elseif($format == 'ISBN-13')
+			{
+				return $A.'-'.$B.'-'.$C.'-'.$D.'-'.$E;
+			}
+			elseif($format == 'EAN')
+			{
+				return $A.$B.$C.$D.$E;
+			}
+		}
+
+		// Private methods
+
+		/**
+		 * Set ISBN Validity
+		 */
+		private function setValid($isValid)
+		{
+			$this->_isValid = (bool) $isValid;
+		}
+
+		/**
+		 * Add to error log
+		 */
+		private function addError($error)
+		{
+			$this->_errors[] = (string) $error;
+		}
+
+		/**
+		 * Delete '-', '_' and ' '
+		 */
+		private function removeHyphens($code)
+		{
+			// Remove Hyphens and others characters
+			$replacements = array('-','_',' ');
+			$code = str_replace($replacements,'',$code);
+
+			// Check for unwanted characters
+			if (!is_numeric($code))
+			{
+				$this->setValid(false);
+				$this->addError(self::ERROR_UNWANTED_CHARACTERS);
+			}
+
+			return $code;
+		}
+
+		/**
+		 * Remove checksum character if present
+		 */
+		private function removeChecksum($code)
+		{
+			$length = strlen($code);
+			if ($length == 13 || $length == 10)
+			{
+				$code = substr_replace($code,"",-1);
+				return $code;
+			}
+			elseif ($length == 12 || $length == 9)
+			{
+				return $code;
+			}
+			else
+			{
+				$this->setValid(false);
+				$this->addError(self::ERROR_INVALID_LENGTH);
+				return $code;
+			}
+		}
+
+		/**
+		 * Remove first three characters if 978 or 979 and save Product Code
+		 */
+		private function removeProductCode($code)
+		{
+			$first3 = substr($code,0,3);
+			if ($first3 == 978 || $first3 == 979) {
+				$this->setProduct($first3);
+				$code = substr($code,3);
+			} else {
+				$this->setProduct(978);
+			}
+			return $code;
+		}
+
+		/**
+		 * Remove and save Country Code
+		 */
+		private function removeCountryCode($code)
+		{
+
+			// Get the seven first digits
+			$first7 = substr($code,0,7);
+
+			// Select the right set of rules according to the product code
+			foreach ($this->_prefixes as $p)
+			{
+				if ($p['Prefix'] == $this->getProduct())
+				{
+					$rules = $p['Rules']['Rule'];
+					break;
+				}
+			}
+
+			// Select the right rule
+			foreach ($rules as $r)
+			{
+				$ra = explode('-',$r['Range']);
+				if ($first7 >= $ra[0] && $first7 <= $ra[1])
+				{
+					$length = $r['Length'];
+					break;
+				}
+			}
+
+			$this->setCountry(substr($code,0,$length));
+			$code = substr($code,$length);
+
+			return $code;
+		}
+
+		/**
+		 * Remove and save Publisher Code and Publication Code
+		 */
+		private function removePublisherCode($code)
+		{
+
+			// Get the seven first digits
+			$first7 = substr($code,0,7);
+
+			// Select the right set of rules according to the agency (product + country code)
+			foreach ($this->_groups as $g)
+			{
+				if ($g['Prefix'] == $this->getProduct().'-'.$this->getCountry())
+				{
+					$rules = $g['Rules']['Rule'];
+					$this->setAgency($g['Agency']);
+					break;
+				}
+			}
+
+			// Select the right rule
+			foreach ($rules as $r)
+			{
+				$ra = explode('-',$r['Range']);
+				if ($first7 >= $ra[0] && $first7 <= $ra[1])
+				{
+					$length = $r['Length'];
+					break;
+				}
+			}
+
+			$this->setPublisher(substr($code,0,$length));
+			$this->setPublication(substr($code,$length));
+
+		}
+
+		/**
+		 * Calculate checksum character
+		 */
+		private function calculateChecksum($format = 'EAN')
+		{
+
+			if ($format == 'ISBN-10')
+			{
+				$code = $this->getCountry().$this->getPublisher().$this->getPublication();
+				$c = str_split($code);
+				$sum = 11 - (($c[0] * 10) + ($c[1] * 9) + ($c[2] * 8) + ($c[3] * 7) + ($c[4] * 6) + ($c[5] * 5) + ($c[6] * 4) + ($c[7] * 3) + ($c[8] * 2)) % 11;
+				if($sum == 10) $sum = 'X';
+			}
+			else
+			{
+				$code = $this->getProduct().$this->getCountry().$this->getPublisher().$this->getPublication();
+				$c = str_split($code);
+				$sum = (10 - ((($c[1] + $c[3] + $c[5] + $c[7] + $c[9] + $c[11]) * 3) + ($c[0] + $c[2] + $c[4] + $c[6] + $c[8] + $c[10]) % 10)) % 10;
+			}
+
+			var_dump($sum);
+
+			$this->setChecksum($sum);
+
+		}
+
+
+		/* SETTERS */
+
+		private function loadRanges($file)
+		{
+			$ranges = simplexml_load_file($file);
+			$ranges = json_encode($ranges);
+			$ranges = json_decode($ranges,TRUE);
+
+			$this->_prefixes = (array) $ranges['EAN.UCCPrefixes']['EAN.UCC'];
+			$this->_groups = (array) $ranges['RegistrationGroups']['Group'];
+		}
+
+		private function setProduct($product)
+		{
+			$this->_product = $product;
+		}
+
+		private function setCountry($country)
+		{
+			$this->_country = $country;
+		}
+
+		private function setPublisher($publisher)
+		{
+			$this->_publisher = $publisher;
+		}
+
+		private function setPublication($publication)
+		{
+			$this->_publication = $publication;
+		}
+
+		private function setChecksum($checksum)
+		{
+			$this->_checksum = $checksum;
+		}
+
+		private function setAgency($agency)
+		{
+			$this->_agency = $agency;
+		}
+
+		/* GETTERS */	
+
+		public function getProduct()
+		{
+			return $this->_product;
+		}
+
+		public function getCountry()
+		{
+			return $this->_country;
+		}
+
+		public function getPublisher()
+		{
+			return $this->_publisher;
+		}
+
+		public function getPublication()
+		{
+			return $this->_publication;
+		}
+
+		public function getChecksum()
+		{
+			return $this->_checksum;
+		}
+
+		public function getAgency()
+		{
+			return $this->_agency;
+		}
+
+		public function getErrors()
+		{
+			$errors = '['.$this->_input.']';
+			foreach ($this->_errors as $e)
+			{
+				$errors .= ' '.$e;
+			}
+			return $errors;
+		}
+
+
+	}
+