org.writersforge.catalan.transform.xml
Class DirectiveStack

java.lang.Object
  org.writersforge.catalan.transform.xml.DirectiveStack

public class DirectiveStack

extends java.lang.Object

Format specification for placing Java Objects into a Datum tree.

Author:

jsheets

Nested Class Summary

static class	DirectiveStack.Attribute A Directive to create a new attribute (Datum property) inside the current element.
static class	DirectiveStack.Directive A single operation to perform on a node while creating a Bellows Datum tree from a list of nodes.
static class	DirectiveStack.EndElement A Directive to close the current element.
static class	DirectiveStack.Pcdata A Directive to insert PCDATA content into the current element.
static class	DirectiveStack.Repeat A Directive to repeat an embedded stack of directives until a certain condition is met.
static class	DirectiveStack.StartElement A Directive to start a new Datum element.

Constructor Summary

DirectiveStack()
Creates a new instance of DirectiveStack.

DirectiveStack(int maxCycles, java.lang.Object untilNode)
Creates a new instance of DirectiveStack with optional maximum iterations and an input node to trigger a premature bailout.

Method Summary

void	addDirective(DirectiveStack.Directive directive) Adds a formatting Directive to the end of the stack.
DirectiveStack.Directive	getNextDirective(java.lang.Object node) Retrieves the next Directive in the stack.
boolean	isFinished() Determines if the stack has reached the end of its run.
static DirectiveStack	loadXmlStack(org.writersforge.bellows.Datum[] directives) Factory method for creating a stack from an XML document.
void	reset() Initializes the stack to its initial state.

Methods inherited from class java.lang.Object

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

Constructor Detail

DirectiveStack

public DirectiveStack()

Creates a new instance of DirectiveStack.

DirectiveStack

public DirectiveStack(int maxCycles,
                      java.lang.Object untilNode)

Creates a new instance of DirectiveStack with optional maximum iterations and an input node to trigger a premature bailout. The DirectiveStack doesn't use these parameters, but does make them available to external code.

Parameters:

maxCycles - the maximum number of times the stack should be processed from start to finish

untilNode - the "bail out" node

Method Detail

addDirective

public void addDirective(DirectiveStack.Directive directive)

Adds a formatting Directive to the end of the stack.

Parameters:

directive - the next Directive to run in the stack

getNextDirective

public DirectiveStack.Directive getNextDirective(java.lang.Object node)

Retrieves the next Directive in the stack. When there are no more Directives, returns a null. If the stack contains any Repeat directives, this method will iterate through them as well.

Parameters:

node - the current node being processed; used to check for 'until-node' matches

Returns:

the next Directive in the stack, or null if stack is empty

isFinished

public boolean isFinished()

Determines if the stack has reached the end of its run. This happens when the stack reaches its maximum number of iterations, or if it hits the untilNode. When the stack is "finished", the method getNextDirective() will always return null. The reset() method returns the stack to a non-finished state.

Returns:

true if the stack is done processing nodes

reset

public void reset()

Initializes the stack to its initial state. Removes any saved state information acquired since creation or the last call to reset().

loadXmlStack

public static DirectiveStack loadXmlStack(org.writersforge.bellows.Datum[] directives)

Factory method for creating a stack from an XML document. Converts XML elements into Directive instances. The <repeat> element can contain other XML directives, which it will iterate through depending on its own parameters (if count is set, or the input data stream (if until-node is set). The XML directives map to Directive constructors like this:

<start-element/>

new DirectiveStack.StartElement()

<start-element name="static-name"/>

new DirectiveStack.StartElement("static-name")

<end-element/>

new DirectiveStack.EndElement()

<attribute/>

new DirectiveStack.Attribute(null, null)

<attribute name="static-name"/>

new DirectiveStack.Attribute("static-name", null)

<attribute value="static-value"/>

new DirectiveStack.Attribute(null, "static-value")

<attribute name="static-name" value="static-value"/>

new DirectiveStack.Attribute("static-name", "static-value")

<pcdata></pcdata>

new DirectiveStack.Pcdata(null)

<pcdata>PCDATA CONTENT</pcdata>

new DirectiveStack.Pcdata("PCDATA CONTENT")

<repeat>...</repeat>

new DirectiveStack.Repeat(new DirectiveStack(1, null))

<repeat count="5">...</repeat>

new DirectiveStack.Repeat(new DirectiveStack(5, null))

<repeat until-node="END">...</repeat>

new DirectiveStack.Repeat(new DirectiveStack(Integer.MAX_VALUE, "END"))

Parameters:

directives - an array of XML directives as described above

Returns:

an instance DirectiveStack corresponding to the XML directives