XPathEvaluator (Apache Commons SCXML 2.0-SNAPSHOT API)

java.lang.Object
- org.apache.commons.scxml2.env.xpath.XPathEvaluator

All Implemented Interfaces:

Serializable, Evaluator
```
public class XPathEvaluator
extends Object
implements Evaluator, Serializable
```
An Evaluator implementation for XPath environments.

Does not support the <script> module, throws UnsupportedOperationException if attempted.

See Also:
Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class XPathEvaluator.XPathEvaluatorProvider
- Nested classes/interfaces inherited from interface org.apache.commons.scxml2.Evaluator
  Evaluator.AssignType

Nested Classes
Modifier and Type	Class and Description
`static class`	`XPathEvaluator.XPathEvaluatorProvider`

Field Summary

Fields
Modifier and Type Field and Description

static String SUPPORTED_DATA_MODEL
- Fields inherited from interface org.apache.commons.scxml2.Evaluator
  DEFAULT_DATA_MODEL, ECMASCRIPT_DATA_MODEL, NULL_DATA_MODEL, XPATH_DATA_MODEL

Fields
Modifier and Type	Field and Description
`static String`	`SUPPORTED_DATA_MODEL`

Constructor Summary

Constructors
Constructor and Description
`XPathEvaluator()` No argument constructor.
`XPathEvaluator(org.apache.commons.jxpath.Functions functions)` Constructor supporting user-defined JXPath `Functions`.

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`assign(Context ctx, Node node, String nodePath, Object data, Evaluator.AssignType type, String attr)`
`void`	`assign(Context ctx, Object location, Object data, Evaluator.AssignType type, String attr)` Assigns data to a location
`Object`	`eval(Context ctx, String expr)` Evaluate an expression returning a data value
`void`	`evalAssign(Context ctx, String location, Object data, Evaluator.AssignType type, String attr)` Assigns data to a location
`Boolean`	`evalCond(Context ctx, String expr)` Evaluate a condition.
`Object`	`evalLocation(Context ctx, String expr)` Evaluate a location that returns a data assignable reference or list of references.
`Object`	`evalScript(Context ctx, String script)` Evaluate a script.
`protected org.apache.commons.jxpath.JXPathContext`	`getContext(Context ctx)`
`String`	`getSupportedDatamodel()` Get the datamodel type supported by this Evaluator
`boolean`	`isXPathLocation(Context ctx, Object data)` Determine if an `Evaluator.evalLocation(Context, String)` returned result represents an XPath location
`Context`	`newContext(Context parent)` Create a new child context.

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

- Field Detail
  - SUPPORTED_DATA_MODEL
```
public static final String SUPPORTED_DATA_MODEL
```
    See Also:
    Constant Field Values
- Constructor Detail
  - XPathEvaluator
```
public XPathEvaluator()
```
    No argument constructor.
  - XPathEvaluator
```
public XPathEvaluator(org.apache.commons.jxpath.Functions functions)
```
    Constructor supporting user-defined JXPath Functions.
    
    Parameters:
    functions - The user-defined JXPath functions to use.
- Method Detail
  - getSupportedDatamodel
```
public String getSupportedDatamodel()
```
    Description copied from interface: Evaluator
    
    Get the datamodel type supported by this Evaluator
    
    Specified by:
    
    getSupportedDatamodel in interface Evaluator
    
    Returns:
    The supported datamodel type
  - eval
```
public Object eval(Context ctx,
          String expr)
            throws SCXMLExpressionException
```
    Description copied from interface: Evaluator
    
    Evaluate an expression returning a data value
    
    Specified by:
    
    eval in interface Evaluator
    
    Parameters:
    ctx - variable context
    expr - expression
    
    Returns:
    the result of the evaluation
    
    Throws:
    
    SCXMLExpressionException - A malformed expression exception
    See Also:
    Evaluator.eval(Context, String)
  - evalCond
```
public Boolean evalCond(Context ctx,
               String expr)
                 throws SCXMLExpressionException
```
    Description copied from interface: Evaluator
    
    Evaluate a condition. Manifests as "cond" attributes of <transition>, <if> and <elseif> elements.
    
    Specified by:
    
    evalCond in interface Evaluator
    
    Parameters:
    ctx - variable context
    expr - expression
    
    Returns:
    true/false
    
    Throws:
    
    SCXMLExpressionException - A malformed expression exception
    See Also:
    Evaluator.evalCond(Context, String)
  - evalLocation
```
public Object evalLocation(Context ctx,
                  String expr)
                    throws SCXMLExpressionException
```
    Description copied from interface: Evaluator
    
    Evaluate a location that returns a data assignable reference or list of references. Manifests as "location" attributes of <assign> element.
    
    Specified by:
    
    evalLocation in interface Evaluator
    
    Parameters:
    ctx - variable context
    expr - expression
    
    Returns:
    The location result.
    
    Throws:
    
    SCXMLExpressionException - A malformed expression exception
    See Also:
    Evaluator.evalLocation(Context, String)
  - evalAssign
```
public void evalAssign(Context ctx,
              String location,
              Object data,
              Evaluator.AssignType type,
              String attr)
                throws SCXMLExpressionException
```
    Description copied from interface: Evaluator
    
    Assigns data to a location
    
    Specified by:
    
    evalAssign in interface Evaluator
    
    Parameters:
    ctx - variable context
    location - location expression
    data - the data to assign.
    type - the type of assignment to perform, null assumes Evaluator.AssignType.REPLACE_CHILDREN
    attr - the name of the attribute to add when using type Evaluator.AssignType.ADD_ATTRIBUTE
    
    Throws:
    
    SCXMLExpressionException - A malformed expression exception
    See Also:
    Evaluator.evalAssign(Context, String, Object, AssignType, String)
  - evalScript
```
public Object evalScript(Context ctx,
                String script)
                  throws SCXMLExpressionException
```
    Description copied from interface: Evaluator
    
    Evaluate a script. Manifests as <script> element.
    
    Specified by:
    
    evalScript in interface Evaluator
    
    Parameters:
    ctx - variable context
    script - The script
    
    Returns:
    The result of the script execution.
    
    Throws:
    
    SCXMLExpressionException - A malformed script
    See Also:
    Evaluator.evalScript(Context, String)
  - newContext
```
public Context newContext(Context parent)
```
    Description copied from interface: Evaluator
    
    Create a new child context.
    
    Specified by:
    
    newContext in interface Evaluator
    
    Parameters:
    parent - parent context
    
    Returns:
    new child context
    See Also:
    Evaluator.newContext(Context)
  - isXPathLocation
```
public boolean isXPathLocation(Context ctx,
                      Object data)
```
    Determine if an Evaluator.evalLocation(Context, String) returned result represents an XPath location
    
    Parameters:
    ctx - variable context
    data - result data from Evaluator.evalLocation(Context, String)
    
    Returns:
    true if the data represents an XPath location
  - assign
```
public void assign(Context ctx,
          Object location,
          Object data,
          Evaluator.AssignType type,
          String attr)
            throws SCXMLExpressionException
```
    Assigns data to a location
    
    Parameters:
    ctx - variable context
    location - location expression
    data - the data to assign.
    type - the type of assignment to perform, null assumes Evaluator.AssignType#REPLACE_CHILDREN
    attr - the name of the attribute to add when using type Evaluator.AssignType#ADD_ATTRIBUTE
    
    Throws:
    
    SCXMLExpressionException - A malformed expression exception
    See Also:
    Evaluator.evalAssign(Context, String, Object, Evaluator.AssignType, String)
  - assign
```
protected void assign(Context ctx,
          Node node,
          String nodePath,
          Object data,
          Evaluator.AssignType type,
          String attr)
               throws SCXMLExpressionException
```
    Throws:
    
    SCXMLExpressionException
  - getContext
```
protected org.apache.commons.jxpath.JXPathContext getContext(Context ctx)
                                                      throws SCXMLExpressionException
```
    Throws:
    
    SCXMLExpressionException

Class XPathEvaluator

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.commons.scxml2.Evaluator

Field Summary

Fields inherited from interface org.apache.commons.scxml2.Evaluator

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SUPPORTED_DATA_MODEL

Constructor Detail

XPathEvaluator

XPathEvaluator

Method Detail

getSupportedDatamodel

eval

evalCond

evalLocation

evalAssign

evalScript

newContext

isXPathLocation

assign

assign

getContext