org.jvoicexml.interpreter.formitem

Class BlockFormItem

java.lang.Object

org.jvoicexml.interpreter.formitem.BlockFormItem

All Implemented Interfaces:

ControlItem, DialogConstruct, FormItem, FormItemLocalExecutableTagContainer, FormItemVisitable

public final class BlockFormItem
extends java.lang.Object

A sequence of procedural statements used for prompting and computation, but not for gathering input. A block has a (normally implicit) form item variable that is set to true, just before it is interpreted.

Constructor Summary

Constructors

Constructor and Description
BlockFormItem() Constructs a new object as a template.
BlockFormItem(VoiceXmlInterpreterContext context, org.jvoicexml.xml.VoiceXmlNode voiceNode) Create a new block form item.

Method Summary

Modifier and Type	Method and Description
void	accept(FormItemVisitor visitor) Execute the specific method of the visitor.
boolean	evaluateCondition() An expression to evaluate in conjunction with the test of the form item variable.
java.lang.Object	evaluateExpression(DataModel model) Retrieves the evaluated expr attribute.
java.util.Collection<org.jvoicexml.xml.vxml.AbstractCatchElement>	getCatchElements() Retrieves all nested catch elements.
protected VoiceXmlInterpreterContext	getContext() Retrieves the current VoiceXmlInterpreterContext.
java.lang.Object	getFormItemVariable() Retrieves the form item variable.
java.util.Collection<org.jvoicexml.xml.VoiceXmlNode>	getLocalExecutableTags() Retrieves the nested tags that have to be executed locally.
java.lang.String	getName() Retrieves the name of this FormItem..
org.jvoicexml.xml.VoiceXmlNode	getNode() Retrieves the encapsulated VoiceXmlNode.
java.lang.String	getNodeTagName() Retrieves the tag name of the encapsulated node.
void	init(DataModel model) Initializes this form item.
boolean	isModal() Checks if this form item is modal.
boolean	isSelectable() Guard conditions, which governs whether or not this form item can be selected by the form interpretation algorithm.
org.jvoicexml.interpreter.formitem.AbstractFormItem	newInstance(VoiceXmlInterpreterContext ctx, org.jvoicexml.xml.VoiceXmlNode voiceNode) Factory method to create a new instance from a template.
int	setFormItemVariable(java.lang.Object value) Sets the value of the form item variable.
void	setVisited() Mark this form item visited by setting the form item variable to true.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jvoicexml.interpreter.FormItem

evaluateCondition, evaluateExpression, getFormItemVariable, getName, getNode, getNodeTagName, isSelectable, setFormItemVariable

Constructor Detail

BlockFormItem

public BlockFormItem()

Constructs a new object as a template.

BlockFormItem

public BlockFormItem(VoiceXmlInterpreterContext context,
                     org.jvoicexml.xml.VoiceXmlNode voiceNode)
              throws java.lang.IllegalArgumentException

Create a new block form item.

Parameters:

context - The current VoiceXmlInterpreterContext.

voiceNode - The corresponding XML node in the VoiceXML document.

Throws:

java.lang.IllegalArgumentException - if the given node is not a Block

Method Detail

newInstance

public org.jvoicexml.interpreter.formitem.AbstractFormItem newInstance(VoiceXmlInterpreterContext ctx,
                                                                       org.jvoicexml.xml.VoiceXmlNode voiceNode)

Factory method to create a new instance from a template.

Parameters:

ctx - The current VoiceXmlInterpreterContext.

voiceNode - The corresponding XML node in the VoiceXML document.

Returns:

created form item

setVisited

public void setVisited()

Mark this form item visited by setting the form item variable to true.

accept

public void accept(FormItemVisitor visitor)
            throws JVoiceXMLEvent

Execute the specific method of the visitor.

Parameters:

visitor - The visitor to use.

Throws:

JVoiceXMLEvent - Error or event visiting the form item.

getCatchElements

public java.util.Collection<org.jvoicexml.xml.vxml.AbstractCatchElement> getCatchElements()

Retrieves all nested catch elements.

Returns:

null, since a <block> must not contain nested catches.

isModal

public boolean isModal()

Checks if this form item is modal. This causes all grammars to be disabled except the ones defined in the current form item.

Returns:

true if the form item is modal.

init

public void init(DataModel model)
          throws SemanticError,
                 BadFetchError

Initializes this form item.

Parameters:

model - the employed data model

Throws:

SemanticError - error initializing this form item

BadFetchError - error initializing this form item

getFormItemVariable

public final java.lang.Object getFormItemVariable()

Retrieves the form item variable.

Each form has an associated form item variable. which by default is set to null when the form is entered. This form item variable will contain the result of interpreting the form item. An input item's form variable can be given a name using the name attribute or left nameless in which case an internal name is generated.

Specified by:

getFormItemVariable in interface FormItem

Returns:

retrieves the value of the associated variable in the DataModel

setFormItemVariable

public int setFormItemVariable(java.lang.Object value)
                        throws SemanticError

Sets the value of the form item variable.

Specified by:

setFormItemVariable in interface FormItem

Parameters:

value - new value for the form item variable.

Returns:

0 if setting the form item variable was successful

Throws:

SemanticError - error setting the value

getName

public final java.lang.String getName()

Retrieves the name of this FormItem..

Specified by:

getName in interface FormItem

Returns:

Name of a dialog scoped form item variable.

evaluateExpression

public final java.lang.Object evaluateExpression(DataModel model)
                                          throws SemanticError

Retrieves the evaluated expr attribute.

Specified by:

evaluateExpression in interface FormItem

Parameters:

model - the data model to use for evaluation

Returns:

evaluated expression of the expr attribute.

Throws:

SemanticError - error evaluating the expr attribute.

evaluateCondition

public boolean evaluateCondition()
                          throws SemanticError

An expression to evaluate in conjunction with the test of the form item variable. If absent, this defaults to true, or in the case of <initial>, a test to see if any input item variable has been filled in.

Specified by:

evaluateCondition in interface FormItem

Returns:

true if the cond attribute of the form item evaluates to true.

Throws:

SemanticError - error evaluating the cond attribute.

isSelectable

public boolean isSelectable()
                     throws SemanticError

Guard conditions, which governs whether or not this form item can be selected by the form interpretation algorithm.

This default guard condition just tests to see if the form item variable has a value. If it does, this form item will not be visited.

Specified by:

isSelectable in interface FormItem

Returns:

true if the form item's variable has no value.

Throws:

SemanticError - error evaluating the cond condition.

See Also:

FormItem.getFormItemVariable()

getNode

public final org.jvoicexml.xml.VoiceXmlNode getNode()

Retrieves the encapsulated VoiceXmlNode.

Specified by:

getNode in interface FormItem

Returns:

Related VoiceXmlNode.

getNodeTagName

public final java.lang.String getNodeTagName()

Retrieves the tag name of the encapsulated node.

Specified by:

getNodeTagName in interface FormItem

Returns:

tag name of the encapsulated node.

getContext

protected final VoiceXmlInterpreterContext getContext()

Retrieves the current VoiceXmlInterpreterContext.

Returns:

the current VoiceXmlInterpreterContext.

getLocalExecutableTags

public java.util.Collection<org.jvoicexml.xml.VoiceXmlNode> getLocalExecutableTags()

Retrieves the nested tags that have to be executed locally.

Specified by:

getLocalExecutableTags in interface FormItemLocalExecutableTagContainer

Returns:

local executable tags.