xsd - XML Schema. Base64binary type vs String type

Question

I need to decode a Base64 string from some XML element. Is there any difference between an element defined by type="xs:base64binary" and an element defined by type="xs:string"? Some XSD developers refuse to mark encoded strings as a base64binary. If there is no difference, what is the use of type="xs:base64binary"?

Answer 1

There definitely is a difference between base64Binary and string in XSD:

• base64Binary represents binary data encoded in Base64. Its value space is the set of fixed length binary octets. Its lexical space is limited to a-z, A-Z, 0-9, +, /, =, plus whitespace.
• string represents character data. Its value space is the set of finite-length sequences of characters. Its lexical space is unconstrained beyond having to consist of XML characters.