uk.ac.sheffield.jast.valid

Class CompoundRule

java.lang.Object

uk.ac.sheffield.jast.valid.GrammarRule

uk.ac.sheffield.jast.valid.CompoundRule

Direct Known Subclasses:

IterationRule, MixedContentRule, SelectionRule, SequenceRule, UnorderedRule

public abstract class CompoundRule
extends GrammarRule

CompoundRule is the abstract ancestor of all compound XML grammar rules. CompoundRule is the parent of SequenceRule, SelectionRule, IterationRule, UnorderedRule and MixedContentRule. It maintains a list of GrammarRule children.

Version:

2.5

Author:

Anthony J H Simons

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<GrammarRule>	production The GrammarRule children of this CompoundRule.
protected static Filter	textFilter The TextFilter used by this CompoundRule.

Fields inherited from class uk.ac.sheffield.jast.valid.GrammarRule

identifier, parent

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CompoundRule(java.lang.String identifier) Creates a CompoundRule, whose rule children are patterns to match against a sequence of XML nodes.

Method Summary

Modifier and Type	Method and Description
void	addChildRule(GrammarRule rule) Adds another child GrammarRule to this CompoundRule.
java.util.List<GrammarRule>	getRuleChildren() Returns the children GrammarRules of this CompoundRule.
protected boolean	hasNoText(Element node) Checks that the tested Element contains no textual content.
protected boolean	matchChildRule(Element node, GrammarRule rule) Matches a general GrammarRule child against an Element's children.
private boolean	matchCompoundRule(Element node, GrammarRule rule) Seeks to match a CompoundRule against the next child or children of the current Element.
private boolean	matchElementRule(Element node, GrammarRule rule) Seeks to match an ElementRule against the next child of the current Element.
protected java.lang.String	toString(GrammarRule rule) Secret method used by all CompoundRules to convert their rule children to pretty String forms.

Methods inherited from class uk.ac.sheffield.jast.valid.GrammarRule

accept, clearError, getChildIndex, getIdentifier, isAttributeRule, isElementRule, isNestingRule, restrict, setChildIndex, setError, setParent, validate

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

textFilter

protected static Filter textFilter

The TextFilter used by this CompoundRule. This is used to filter the contents of an Element to determine whether textual content is present. This is illegal in most CompoundRules, but allowed in a MixedContentRule.

production

private java.util.List<GrammarRule> production

The GrammarRule children of this CompoundRule. These rules will be applied in order to validate a sequence of terms.

Constructor Detail

CompoundRule

protected CompoundRule(java.lang.String identifier)

Creates a CompoundRule, whose rule children are patterns to match against a sequence of XML nodes. By default, this constructor is used by every kind of CompoundRule except IterationRule.

Parameters:

identifier - the symbolic identifier of this CompoundRule.

Method Detail

hasNoText

protected boolean hasNoText(Element node)

Checks that the tested Element contains no textual content. If the Element contains any Text or Data nodes with printing content, returns false and records a mismatch; otherwise returns true. This method is used by nearly all CompoundRule rules to exclude Text and Data nodes from the DTD grammar production rule. MixedContentRule is the only CompoundRule that allows Text or Data.

Parameters:

node - an Element.

Returns:

true if the Element has no Text or Data contents.

matchChildRule

protected boolean matchChildRule(Element node,
                                 GrammarRule rule)

Matches a general GrammarRule child against an Element's children. Starts to match at the next child index. Returns true if the child rule succeeds, otherwise returns false.

Parameters:

node - an XML Element.

rule - any child GrammarRule.

Returns:

true if the rule succeeds; otherwise false.

matchCompoundRule

private boolean matchCompoundRule(Element node,
                                  GrammarRule rule)

Seeks to match a CompoundRule against the next child or children of the current Element. Starts to match at the next child index. Returns true if the rule succeeds, otherwise returns false and resets the child index.

Parameters:

node - an Element.

rule - a CompoundRule.

Returns:

true if the rule succeeds; otherwise false.

matchElementRule

private boolean matchElementRule(Element node,
                                 GrammarRule rule)

Seeks to match an ElementRule against the next child of the current Element. Starts to match at the next child index. Succeeds if there are more child nodes, and the next child node matches the ElementRule. Fails if there are no more child nodes, or the next child fails to

Parameters:

node - an Element.

rule - an ElementRule.

Returns:

true if the rule succeeds; otherwise false.

addChildRule

public void addChildRule(GrammarRule rule)

Adds another child GrammarRule to this CompoundRule. The child rule may be any kind of rule that may nest inside a CompoundRule, such as an ElementRule, SequenceRule, SelectionRule, IterationRule, or UnorderedRule. The SimpleRule rules and MixedContentRule may not be nested inside a CompoundRule.

Overrides:

addChildRule in class GrammarRule

Parameters:

rule - the GrammarRule to add.

getRuleChildren

public java.util.List<GrammarRule> getRuleChildren()

Returns the children GrammarRules of this CompoundRule.

Overrides:

getRuleChildren in class GrammarRule

Returns:

the children of this rule.

toString

protected java.lang.String toString(GrammarRule rule)

Secret method used by all CompoundRules to convert their rule children to pretty String forms. The main reason for this is to ensure that ElementRule children are rendered by their name only, and not by a full production, which is the normal String representation.

Parameters:

rule - a GrammarRule child of this CompoundRule.

Returns:

the pretty string representation.