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org.apache.xerces.impl.dtd
public class: XMLContentSpec [javadoc | source]
java.lang.Object
   org.apache.xerces.impl.dtd.XMLContentSpec
ContentSpec really exists to aid the parser classes in implementing access to the grammar.

This class is used by the DTD scanner and the validator classes, allowing them to be used separately or together. This "struct" class is used to build content models for validation, where it is more efficient to fetch all of the information for each of these content model "fragments" than to fetch each field one at a time. Since configurations are allowed to have validators without a DTD scanner (i.e. a schema validator) and a DTD scanner without a validator (non-validating processor), this class can be used by each without requiring the presence of the other.

When processing element declarations, the DTD scanner will build up a representation of the content model using the node types that are defined here. Since a non-validating processor only needs to remember the type of content model declared (i.e. ANY, EMPTY, MIXED, or CHILDREN), it is free to discard the specific details of the MIXED and CHILDREN content models described using this class.

In the typical case of a validating processor reading the grammar of the document from a DTD, the information about the content model declared will be preserved and later "compiled" into an efficient form for use during element validation. Each content spec node that is saved is assigned a unique index that is used as a handle for the "value" or "otherValue" fields of other content spec nodes. A leaf node has a "value" that is either an index in the string pool of the element type of that leaf, or a value of -1 to indicate the special "#PCDATA" leaf type used in a mixed content model.

For a mixed content model, the content spec will be made up of leaf and choice content spec nodes, with an optional "zero or more" node. For example, the mixed content declaration "(#PCDATA)" would contain a single leaf node with a node value of -1. A mixed content declaration of "(#PCDATA|foo)*" would have a content spec consisting of two leaf nodes, for the "#PCDATA" and "foo" choices, a choice node with the "value" set to the index of the "#PCDATA" leaf node and the "otherValue" set to the index of the "foo" leaf node, and a "zero or more" node with the "value" set to the index of the choice node. If the content model has more choices, for example "(#PCDATA|a|b)*", then there will be more corresponding choice and leaf nodes, the choice nodes will be chained together through the "value" field with each leaf node referenced by the "otherValue" field.

For element content models, there are sequence nodes and also "zero or one" and "one or more" nodes. The leaf nodes would always have a valid string pool index, as the "#PCDATA" leaf is not used in the declarations for element content models.

Nested Class Summary:
public interface  XMLContentSpec.Provider  Provides a means for walking the structure built out of content spec "nodes". The user of this provider interface is responsible for knowing what the content spec node values "mean". If those values refer to content spec identifiers, then the user can call back into the provider to get the next content spec node in the structure. 
Field Summary
public static final  short CONTENTSPECNODE_LEAF    Name or #PCDATA. Leaf nodes that represent parsed character data (#PCDATA) have values of -1. 
public static final  short CONTENTSPECNODE_ZERO_OR_ONE    Represents a zero or one occurence count, '?'. 
public static final  short CONTENTSPECNODE_ZERO_OR_MORE    Represents a zero or more occurence count, '*'. 
public static final  short CONTENTSPECNODE_ONE_OR_MORE    Represents a one or more occurence count, '+'. 
public static final  short CONTENTSPECNODE_CHOICE    Represents choice, '|'. 
public static final  short CONTENTSPECNODE_SEQ    Represents sequence, ','. 
public static final  short CONTENTSPECNODE_ANY    Represents any namespace specified namespace. When the element found in the document must belong to a specific namespace, otherValue will contain the name of the namespace. If otherValue is -1 then the element can be from any namespace.

Lists of valid namespaces are created from choice content spec nodes that have any content spec nodes as children. 

public static final  short CONTENTSPECNODE_ANY_OTHER    Represents any other namespace (XML Schema: ##other).

When the content spec node type is set to CONTENTSPECNODE_ANY_OTHER, value will contain the namespace that cannot occur. 

public static final  short CONTENTSPECNODE_ANY_LOCAL    Represents any local element (XML Schema: ##local). 
public static final  short CONTENTSPECNODE_ANY_LAX    prcessContent is 'lax' 
public static final  short CONTENTSPECNODE_ANY_OTHER_LAX     
public static final  short CONTENTSPECNODE_ANY_LOCAL_LAX     
public static final  short CONTENTSPECNODE_ANY_SKIP    processContent is 'skip' 
public static final  short CONTENTSPECNODE_ANY_OTHER_SKIP     
public static final  short CONTENTSPECNODE_ANY_LOCAL_SKIP     
public  short type    The content spec node type. 
public  Object value    The "left hand" value object of the content spec node. leaf name.localpart, single child for unary ops, left child for binary ops. 
public  Object otherValue    The "right hand" value of the content spec node. leaf name.uri, right child for binary ops 
Constructor:
 public XMLContentSpec() 
 public XMLContentSpec(XMLContentSpec contentSpec) 
    Constructs a content spec from the values in the specified content spec.
 public XMLContentSpec(XMLContentSpec.Provider provider,
    int contentSpecIndex) 
    Constructs a content spec from the values specified by the given content spec provider and identifier.
 public XMLContentSpec(short type,
    Object value,
    Object otherValue) 
    Constructs a content spec with the specified values.
Method from org.apache.xerces.impl.dtd.XMLContentSpec Summary:
clear,   equals,   hashCode,   setValues,   setValues,   setValues
Methods from java.lang.Object:
equals,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.xerces.impl.dtd.XMLContentSpec Detail:
 public  void clear() 
    Clears the values.
 public boolean equals(Object object) 
    Returns true if the two objects are equal.
 public int hashCode() 
    Returns a hash code for this node.
 public  void setValues(XMLContentSpec contentSpec) 
    Sets the values of the specified content spec.
 public  void setValues(XMLContentSpec.Provider provider,
    int contentSpecIndex) 
    Sets the values from the values specified by the given content spec provider and identifier. If the specified content spec cannot be provided, the values of this content spec are cleared.
 public  void setValues(short type,
    Object value,
    Object otherValue) 
    Sets the values.