"base64Binary" Datatype Values and Representations

XSD Tutorials - Herong's Tutorial Examples

∟"base64Binary" Datatype Values and Representations

This section describes the built-in primitive datatype, 'base64Binary' that represents binary data represented in Base64 encoding. Whitespaces are allowed and removed.

"base64Binary" is a built-in datatype that represents binary data encoded with Base64 algorithm with these rules:

The value space of "base64Binary" is any binary data.
The lexical space of "base64Binary" is Base64 encoding output strings.
Whitespaces allowed and removed.

To verify these rules, I wrote this simple XSD document that uses "base64Binary" datatype to declare XML elements:

<?xml version="1.1"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<!-- base64Binary_datatype_test.xsd
 - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved.
-->
<xs:element name="Base64Binary_Datatype_Test">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="Base64Binary" type="xs:base64Binary"
         maxOccurs="unbounded"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

Here is a sample XML document that can be used to test these declarations:

<?xml version="1.1"?>
<!-- base64Binary_datatype_test.xml
 - Copyright (c) 2002-2013 HerongYang.com. All Rights Reserved.
-->
<Base64Binary_Datatype_Test>

<!-- 4 valid "Base64Binary" elements -->
  <Base64Binary>    QQ==   </Base64Binary>
  <Base64Binary>    aGVyb25neWFuZy5jb20=   </Base64Binary>
  <Base64Binary> a G  V   y   b  2 5neWFuZy5jb20=   </Base64Binary>
  <Base64Binary>    1234   </Base64Binary>

<!-- 4 invalid "Base64Binary" elements -->
  <Base64Binary>    123   </Base64Binary>
  <Base64Binary>    herongyang.com==   </Base64Binary>
  <Base64Binary>    QQ==QQ==   </Base64Binary>
  <Base64Binary>    Q===   </Base64Binary>
</Base64Binary_Datatype_Test>

When validating this XML document with my XsdSchemaValidator.java program presented earlier in the book, I get 4 groups of errors for 4 invalid XML elements:

herong> java XsdSchemaValidator
^^^ base64Binary_datatype_test.xsd base64Binary_datatype_test.xml

Error:
   Line number: 14
   Column number: 42
   Message: cvc-datatype-valid.1.2.1: '    123   ' is not a valid
   value for 'base64Binary'. (must be multiples of 4 characters)

Error:
   Line number: 14
   Column number: 42
   Message: cvc-type.3.1.3: The value '    123   ' of element
   'Base64Binary' is not valid.

Error:
   Line number: 15
   Column number: 55
   Message: cvc-datatype-valid.1.2.1: '    herongyang.com==   ' is not
   a valid value for 'base64Binary'. ("." not allowed)

Error:
   Line number: 15
   Column number: 55
   Message: cvc-type.3.1.3: The value '    herongyang.com==   ' of
   element 'Base64Binary' is not valid.

Error:
   Line number: 16
   Column number: 47
   Message: cvc-datatype-valid.1.2.1: '    QQ==QQ==   ' is not a valid
   value for 'base64Binary'. ("=" only allowed at the end)

Error:
   Line number: 16
   Column number: 47
   Message: cvc-type.3.1.3: The value '    QQ==QQ==   ' of element
   'Base64Binary' is not valid.

Error:
   Line number: 17
   Column number: 43
   Message: cvc-datatype-valid.1.2.1: '    Q===   ' is not a valid
   value for 'base64Binary'. (maximum 2 "=" at the end)

Error:
   Line number: 17
   Column number: 43
   Message: cvc-type.3.1.3: The value '    Q===   ' of element
   'Base64Binary' is not valid.

Error:
   Line number: 17
   Column number: 43
   Message: cvc-type.3.1.3: The value '    Q===   ' of element 'Base64Binary'
   is not valid.

Failed with errors: 9