Zend_Validate_Barcode allows you to check if a given value can be represented as barcode. Zend_Validate_Barcode supports multiple barcode standards and can be extended with proprietary barcode implementations very easily. The following barcode standards are supported: CODE25: Often called "two of five." This barcode has no length limitation, but it must contain an even amount of characters. It supports only digits, and the last digit can be an optional checksum which is calculated with modulo 10. This standard is used worldwide and common on the market. CODE39: CODE39 is one of the oldest available codes. This barcode has a variable length. It supports digits, alphabetical characters and 7 special characters. It can have an optional checksum which is calculated with modulo 43. This standard is used worldwide and common within the industry. CODE93: CODE93 is the successor of CODE39. This barcode has a variable length. It supports digits, alphabetical characters and 7 special characters. It has an checksum which is calculated with modulo 47 and contains 2 characters. This standard produces a denser code than CODE39 and is more secure. EAN8: EAN is the shortcut for "European Article Number". These barcodes must have a length of 8 characters. It supports only digits, and the last digit is always a checksum. This standard is used worldwide but has a very limited range. It can be found on small articles where a longer barcode could not be printed. EAN12: EAN is the shortcut for "European Article Number". This barcode must have a length of 12 characters. It supports only digits, and the last digit is always a checksum which is calculated with modulo 10. This standard is used within the USA and common on the market. It has been superceded by EAN13. EAN13: EAN is the shortcut for "European Article Number". This barcode must have a length of 13 characters. It supports only digits, and the last digit is always a checksum which is calculated with modulo 10. This standard is used worldwide and common on the market. EAN14: EAN is the shortcut for "European Article Number". This barcode must have a length of 14 characters. It supports only digits, and the last digit is always a checksum which is calculated with modulo 10. This standard is used worldwide and common on the market. It is the successor for EAN13. GTIN12: GTIN is the shortcut for "Global Trade Item Number". This barcode uses the same standard as EAN12 and is its successor. It's commonly used within the USA. GTIN13: GTIN is the shortcut for "Global Trade Item Number". This barcode uses the same standard as EAN13 and is its successor. It is used worldwide by industry. GTIN14: GTIN is the shortcut for "Global Trade Item Number". This barcode uses the same standard as EAN14 and is its successor. It is used worldwide and common on the market. ITF14: ITF14 is the GS1 implementation of an Interleaved Two of Five bar code. This barcode is a special variant of Interleaved 2 of 5. It must have a length of 14 characters and is based on GTIN14. It supports only digits, and the last digit must be a checksum digit which is calculated with modulo 10. It is used worldwide and common within the market. SSCC: SSCC is the shortcut for "Serial Shipping Container Code". This barcode is a variant of EAN barcode. It must have a length of 18 characters and supports only digits. The last digit must be a checksum digit which is calculated with modulo 10. It is commonly used by the transport industry. UPCA: UPC is the shortcut for "Univeral Product Code". This barcode preceeded EAN13. It must have a length of 12 characters and supports only digits. The last digit must be a checksum digit which is calculated with modulo 10. It is commonly used within the USA. UPCE: UPCE is the short variant from UPCA. This barcode is a smaller variant of UPCA. It must have a length of 6 characters and supports only digits. There is no checksum within this barcode. It is commonly used with small products where a UPCA barcode would not fit. To validate if a given string is a barcode you just need to know its type. See the following example for an EAN13 barcode: isValid($input)) { // input appears to be valid } else { // input is invalid } ]]> Some barcodes can be provided with an optional checksum. These barcodes would be valid even without checksum. Still, when you provide a checksum, then you should also validate it. By default, these barcode types perform no checksum validation. By using the checksum option you can define if the checksum will be validated or ignored. 'EAN13', 'checksum' => false, )); if ($valid->isValid($input)) { // input appears to be valid } else { // input is invalid } ]]> By switching off checksum validation you will also reduce the security of the used barcodes. Additionally you should note that you can also turn off the checksum validation for those barcode types which must contain a checksum value. Barcodes which would not be valid could then be returned as valid even if they are not. You may write custom barcode validators for usage with Zend_Validate_Barcode; this is often necessary when dealing with proprietary barcode types. To write your own barcode validator, you need the following information. Length: The length your barcode must have. It can have one of the following values: Integer: A value greater 0, which means that the barcode must have this length. -1: There is no limitation for the length of this barcode. "even": The length of this barcode must have a even amount of digits. "odd": The length of this barcode must have a odd amount of digits. array: An array of integer values. The length of this barcode must have one of the set array values. Characters: A string which contains all allowed characters for this barcode. Also the integer value 128 is allowed, which means the first 128 characters of the ASCII table. Checksum: A string which will be used as callback for a method which does the checksum validation. Your custom barcode validator must extend Zend_Validate_Barcode_AdapterAbstract or implement Zend_Validate_Barcode_AdapterInterface. As an example, let's create a validator that expects an even number of characters that include all digits and the letters 'ABCDE', and which requires a checksum. isValid($input)) { // input appears to be valid } else { // input is invalid } ]]>