## com.saxonica.schema
Class AttributeUse

    java.lang.Object
      com.saxonica.schema.SchemaStructure
          com.saxonica.schema.SimpleComponentReference
              com.saxonica.schema.AttributeUse

All Implemented Interfaces:
  ComponentReference, UserSchemaComponent, Serializable, SourceLocator, SchemaComponent

    public final class AttributeUse

extends SimpleComponentReference
implements UserSchemaComponent

An XML Schema Attribute Use: that is, a reference to an attribute declaration from within a complex type or attribute group.

This corresponds to an xs:attribute ref="" element in the XML representation of the schema.

Technically, a local attribute declaration (a non global xs:attribute name="") should be represented by two schema components, an attribute use and an attribute declaration. We don't currently do this, instead the containing attribute group refers to the attribute declaration directly.

See Also:
  Serialized Form

Field Summary
`static short` `OPTIONAL` Value representing use="optional"
`static short` `PROHIBITED` Value representing use="prohibited"
`static short` `REQUIRED` Value representing use="required"

Fields inherited from class com.saxonica.schema.SimpleComponentReference
`nameCode, symbolSpace, target`

Fields inherited from interface net.sf.saxon.type.SchemaComponent
`FIXED_UP, INCOMPLETE, INVALID, UNVALIDATED, VALIDATED, VALIDATING`

Constructor Summary
`AttributeUse(EnterpriseConfiguration config)` Creates a new Attribute Use in the given schema.

Method Summary
`boolean` `fixup(SchemaCompiler compiler)` Fix up references to other elements in the schema.
`AttributeDecl` `getAttributeDeclaration()` Get the corresponding attribute declaration
`int` `getCardinality()` Get the value of the "use" attribute, expressed as a Cardinality value of `StaticProperty.EXACTLY_ONE`, `StaticProperty.EMPTY`, or `StaticProperty.ALLOWS_ZERO_OR_ONE`
`String` `getDefaultValue()` Returns the default value of this attribute use.
`String` `getDisplayName()` Returns the name of the attribute defined by this AttributeDecl.
`Value` `getFixedValue()` Returns the fixed value of this attribute use.
`String` `getUnderlyingDefaultValue()` Get the default value of this attribute use if there is one; if there is none, get the default value of the corresponding attribute declaration; if the declaration defines no default value, return null
`Value` `getUnderlyingFixedValue()` Returns the fixed value of this attribute use, or of the corresponding attribute declaration if the attribute use has no fixed value.
`String` `getUse()` Get the value of the 'use' attribute for this attribute declaration or attribute reference.
`boolean` `isInheritable()` Ask whether this attribute is inheritable
`boolean` `isOptional()` Returns true if the use attribute is equal to "optional".
`boolean` `isProhibited()` Returns true if the use attribute is equal to "prohibited".
`boolean` `isRequired()` Returns true if the 'use' attribute is equal to REQUIRED and there is no specified value.
`void` `serialize(SchemaModelSerializer serializer)` Serialize the schema component
`void` `setDefaultValue(String value)` Sets the default value.
`void` `setFixedValue(Value value)` Sets the fixed value.
`void` `setInheritable(int inherit)` Say whether this attribute is inheritable
`void` `setNamespaceResolver(NamespaceResolver resolver)` Set the namespace resolver for resolving QName-valued fixed and default values
`void` `setUse(short value)` Sets the 'use' attribute of this attribute declaration.
`boolean` `testFixedValue(CharSequence value, NamespaceResolver resolver)` Test a value against the fixed value.
`boolean` `validate(SchemaCompiler compiler)` Checks the validity of this Attribute Use

Methods inherited from class com.saxonica.schema.SimpleComponentReference
`getFingerprint, getNameCode, getSymbolSpace, getTarget, isResolved, setNameCode, setTarget, tryToResolve`

Methods inherited from class com.saxonica.schema.SchemaStructure
`elaborate, getColumnNumber, getConfiguration, getFixupStatus, getLineNumber, getPublicId, getRedefinitionLevel, getSchemaDocumentURI, getSystemId, getValidationStatus, lookForCycles, setConfiguration, setFixupStatus, setLineNumber, setLocator, setRedefinitionLevel, setSchemaDocumentURI, setSystemId, setValidationStatus`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Methods inherited from interface com.saxonica.schema.UserSchemaComponent
`elaborate, lookForCycles`

Methods inherited from interface net.sf.saxon.type.SchemaComponent
`getRedefinitionLevel, getValidationStatus`

Methods inherited from interface com.saxonica.schema.ComponentReference
`getConfiguration`

Methods inherited from interface javax.xml.transform.SourceLocator
`getColumnNumber, getLineNumber, getPublicId, getSystemId`

Field Detail

### OPTIONAL

    public static final short OPTIONAL

  Value representing use="optional"

  See Also:
    Constant Field Values

### PROHIBITED

    public static final short PROHIBITED

  Value representing use="prohibited"

  See Also:
    Constant Field Values

### REQUIRED

    public static final short REQUIRED

  Value representing use="required"

  See Also:
    Constant Field Values

Constructor Detail

### AttributeUse

    public AttributeUse(EnterpriseConfiguration config)

  Creates a new Attribute Use in the given schema. For system use only.

  Parameters:
    `config` - the Configuration that contains the new attributeUse

Method Detail

### getAttributeDeclaration

    public AttributeDecl getAttributeDeclaration()
                                          throws UnresolvedReferenceException

  Get the corresponding attribute declaration

  Returns:
    the attribute declaration referenced by this attribute use
  Throws:
    `UnresolvedReferenceException`

### getDisplayName

    public String getDisplayName()

  Returns the name of the attribute defined by this AttributeDecl. This is used only for diagnostic display purposes

  Returns:
    the name of the attribute as a lexical QName.

### getUse

    public String getUse()

  Get the value of the 'use' attribute for this attribute declaration or attribute reference. If this is a reference the value of the use attribute will *not* be obtained from the referenced attribute declaration as top-level attributes do not take into account the use attribute.

  Returns:
    the value of the 'use' attribute for this attribute declaration, as a string: "prohibited", "required", or "optional".

### getCardinality

    public int getCardinality()

  Get the value of the "use" attribute, expressed as a Cardinality value of `StaticProperty.EXACTLY_ONE`, `StaticProperty.EMPTY`, or `StaticProperty.ALLOWS_ZERO_OR_ONE`

  Returns:
    the cardinality implied by the "use" attribute

### getDefaultValue

    public String getDefaultValue()

  Returns the default value of this attribute use.

  Returns:
    the default value defined by this attribute declaration, or null if no default was specified.

### getUnderlyingDefaultValue

    public String getUnderlyingDefaultValue()

  Get the default value of this attribute use if there is one; if there is none, get the default value of the corresponding attribute declaration; if the declaration defines no default value, return null

  Returns:
    the default attribute value if there is one, otherwise null

### getFixedValue

    public Value getFixedValue()

  Returns the fixed value of this attribute use.

  Returns:
    the fixed value defined by this attribute use, or null if no fixed value was specified. Once the schema has been compiled this will be the correctly-typed value; until then it will be the string value as specified in the source schema.

### getUnderlyingFixedValue

    public Value getUnderlyingFixedValue()

  Returns the fixed value of this attribute use, or of the corresponding attribute declaration if the attribute use has no fixed value.

  Returns:
    the fixed value defined by this attribute use, if one was specified; failing that, the fixed value defined for the corresponding attribute declaration; failing that, null. Once the schema has been compiled this will be the correctly-typed value; until then it will be the string value as specified in the source schema.

### setNamespaceResolver

    public void setNamespaceResolver(NamespaceResolver resolver)

  Set the namespace resolver for resolving QName-valued fixed and default values

  Parameters:
    `resolver` - the namespace resolver to be used

### testFixedValue

    public boolean testFixedValue(CharSequence value,
                                  NamespaceResolver resolver)
                           throws ValidationException

  Test a value against the fixed value. This tests both against the fixed value for this attribute use, and the fixed value of the corresponding attribute declaration (which must be equivalent if they are both present).

  Parameters:
    `value` - the value to be tested
    `resolver` - the namespace resolver to be used if the value is namespace sensitive
  Returns:
    true if it matches (or if there is no fixed value), false otherwise
  Throws:
    `ValidationException` - if the value is not valid for this type

### isOptional

    public boolean isOptional()

  Returns true if the use attribute is equal to "optional".

  Returns:
    true if the use attribute is equal to "optional".

### isProhibited

    public boolean isProhibited()

  Returns true if the use attribute is equal to "prohibited". Note that in the W3C schema component model, no attribute use ever has the value "prohibited": this should be treated as if the attribute use did not exist.

  Returns:
    true if the use attribute is equal to "prohibited".

### isRequired

    public boolean isRequired()

  Returns true if the 'use' attribute is equal to REQUIRED and there is no specified value. If a value is specified and the 'use' attribute is "required" then required is will return false, because the attribute value automatically becomes fixed.

  Returns:
    true if the use attribute is equal to "required" and no default value has been specified, otherwise false

### setUse

    public void setUse(short value)

  Sets the 'use' attribute of this attribute declaration. For internal use only.

  Parameters:
    `value` - one of the following: ("prohibited" | "optional" | "required")

### setDefaultValue

    public void setDefaultValue(String value)

  Sets the default value. For internal use only.

  Parameters:
    `value` - the default value

### setFixedValue

    public void setFixedValue(Value value)

  Sets the fixed value. For internal use only.

  Parameters:
    `value` - the fixed value

### setInheritable

    public void setInheritable(int inherit)

  Say whether this attribute is inheritable

  Parameters:
    `inherit` - values are 0 (false), 1 (true), -1 (unspecified, use value from attribute declaration)

### isInheritable

    public boolean isInheritable()

  Ask whether this attribute is inheritable

  Returns:
    true if it is inheritable

### fixup

    public boolean fixup(SchemaCompiler compiler)
                  throws SchemaException

  Fix up references to other elements in the schema. This implementation does nothing

  Specified by:
    `fixup` in interface `UserSchemaComponent`
  Overrides:
    `fixup` in class `SchemaStructure`
  Parameters:
    `compiler` - the schema compiler, used for error reporting
  Returns:
    true if successful.
  Throws:
    `SchemaException`

### validate

    public boolean validate(SchemaCompiler compiler)
                     throws SchemaException

  Checks the validity of this Attribute Use

  Specified by:
    `validate` in interface `UserSchemaComponent`
  Returns:
    true when this Schema definition is valid, otherwise false.
  Throws:
    `SchemaException` - if the error listener decides an error is fatal

### serialize

    public void serialize(SchemaModelSerializer serializer)
                   throws XPathException

  Serialize the schema component

  Parameters:
    `serializer` - the schema serializer
  Throws:
    `XPathException`

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.