Top Description Fields Constructors Methods
com.sun.faces.facelets.el

public final Class ContextualCompositeValueExpression

extends ValueExpression
Class Inheritance
Imports
com.sun.faces.component.CompositeComponentStackManager, javax.el.ValueExpression, .ELContext, javax.faces.view.Location, javax.faces.component.UIComponent, javax.faces.context.FacesContext

This specialized ValueExpression enables the evaluation of composite component expressions. Instances of this expression will be created when com.sun.faces.facelets.tag.TagAttributeImpl#getValueExpression(javax.faces.view.facelets.FaceletContext, Class) is invoked and the expression represents a composite component expression (i.e. #{cc.[properties]}).

It's important to note that these ValueExpressions are context sensitive in that they leverage the location in which they were referenced in order to push the proper composite component to the evaluation context prior to evaluating the expression itself.

Here's an example: 
Using Page test.xhtml
---------------------------------
   <ez:comp1 greeting="Hello!" />


comp1.xhtml
---------------------------------
<composite:interface>
   <composite:attribute name="greeting" type="java.lang.String" required="true" />
</composite:interface>
<composite:implementation>
   <ez:nesting>
      <h:outputText value="#{cc.attrs.greetings}" />
   </ez:nesting>
</composite:implementation>

nesting.xhtml
---------------------------------
<composite:interface />
<composite:implementation>
   <composite:insertChildren>
</composite:implementation>

In the above example, there will be two composite components available to the runtime: ez:comp1 and ez:nesting.

When <h:outputText value="#{cc.attrs.greeting}" />, prior to attempting to evaluate the expression, the Location object will be used to find the composite component that 'owns' the template in which the expression was defined in by comparing the path of the Location with the name and library of the javax.faces.application.Resource instance associated with each composite component. If a matching composite component is found, it will be made available to the EL by calling CompositeComponentStackManager#push(javax.faces.component.UIComponent).

Field Summary

Modifier and TypeField and Description
private Location
location

private ValueExpression
originalVE

private static final long
serialVersionUID

Constructor Summary

AccessConstructor and Description
public
ContextualCompositeValueExpression()

public
ContextualCompositeValueExpression(Location location, ValueExpression originalVE)

Method Summary

Modifier and TypeMethod and Description
public boolean
equals(Object
the Object to test for equality.
o)

Implements abstract javax.el.Expression.equals.

Determines whether the specified object is equal to this Expression.
public Class<?>
getExpectedType()

Implements abstract javax.el.ValueExpression.getExpectedType.

Returns the type the result of the expression will be coerced to after evaluation.
public String
getExpressionString()

Implements abstract javax.el.Expression.getExpressionString.

Returns the original String used to create this Expression, unmodified.
public Location

Returns:

the Location of this ValueExpression
getLocation()

public Class<?>
getType(ELContext
The context of this evaluation.
elContext)

Implements abstract javax.el.ValueExpression.getType.

Evaluates the expression relative to the provided context, and returns the most general type that is acceptable for an object to be passed as the value parameter in a future call to the setValue method.
public Object
getValue(ELContext
The context of this evaluation.
elContext)

Implements abstract javax.el.ValueExpression.getValue.

Evaluates the expression relative to the provided context, and returns the resulting value.
public int
hashCode()

Implements abstract javax.el.Expression.hashCode.

Returns the hash code for this Expression.
public boolean
isLiteralText()

Implements abstract javax.el.Expression.isLiteralText.

Returns whether this expression was created from only literal text.
public boolean
isReadOnly(ELContext
The context of this evaluation.
elContext)

Implements abstract javax.el.ValueExpression.isReadOnly.

Evaluates the expression relative to the provided context, and returns true if a call to setValue will always fail.
private void
popCompositeComponent(FacesContext ctx)

private boolean
pushCompositeComponent(FacesContext ctx)

public void
setValue(ELContext
The context of this evaluation.
elContext, Object
The new value to be set.
o)

Implements abstract javax.el.ValueExpression.setValue.

Evaluates the expression relative to the provided context, and sets the result to the provided value.
public String
toString()

Overrides java.lang.Object.toString.

Returns a string representation of the object.
Inherited from javax.el.ValueExpression:
getValueReference

Field Detail

locationback to summary
private Location location
originalVEback to summary
private ValueExpression originalVE
serialVersionUIDback to summary
private static final long serialVersionUID

Constructor Detail

ContextualCompositeValueExpressionback to summary
public ContextualCompositeValueExpression()
ContextualCompositeValueExpressionback to summary
public ContextualCompositeValueExpression(Location location, ValueExpression originalVE)

Method Detail

equalsback to summary
public boolean equals(Object o)

Implements abstract javax.el.Expression.equals.

Doc from javax.el.Expression.equals.

Determines whether the specified object is equal to this Expression.

The result is true if and only if the argument is not null, is an Expression object that is the of the same type (ValueExpression or MethodExpression), and has an identical parsed representation.

Note that two expressions can be equal if their expression Strings are different. For example, ${fn1:foo()} and ${fn2:foo()} are equal if their corresponding FunctionMappers mapped fn1:foo and fn2:foo to the same method.

Parameters
o:Object

the Object to test for equality.

Returns:boolean

true if obj equals this Expression; false otherwise.

Annotations
@SuppressWarnings:EqualsWhichDoesntCheckParameterClass
@Override
getExpectedTypeback to summary
public Class<?> getExpectedType()

Implements abstract javax.el.ValueExpression.getExpectedType.

Doc from javax.el.ValueExpression.getExpectedType.

Returns the type the result of the expression will be coerced to after evaluation.

Returns:Class<?>

the expectedType passed to the ExpressionFactory.createValueExpression method that created this ValueExpression.

Annotations
@Override
getExpressionStringback to summary
public String getExpressionString()

Implements abstract javax.el.Expression.getExpressionString.

Doc from javax.el.Expression.getExpressionString.

Returns the original String used to create this Expression, unmodified.

This is used for debugging purposes but also for the purposes of comparison (e.g. to ensure the expression in a configuration file has not changed).

This method does not provide sufficient information to re-create an expression. Two different expressions can have exactly the same expression string but different function mappings. Serialization should be used to save and restore the state of an Expression.

Returns:String

The original expression String.

Annotations
@Override
getLocationback to summary
public Location getLocation()
Returns:Location

the Location of this ValueExpression

getTypeback to summary
public Class<?> getType(ELContext elContext)

Implements abstract javax.el.ValueExpression.getType.

Doc from javax.el.ValueExpression.getType.

Evaluates the expression relative to the provided context, and returns the most general type that is acceptable for an object to be passed as the value parameter in a future call to the setValue method.

This is not always the same as getValue().getClass(). For example, in the case of an expression that references an array element, the getType method will return the element type of the array, which might be a superclass of the type of the actual element that is currently in the specified array element.

Parameters
elContext:ELContext

The context of this evaluation.

Returns:Class<?>

the most general acceptable type; otherwise undefined.

Annotations
@Override
getValueback to summary
public Object getValue(ELContext elContext)

Implements abstract javax.el.ValueExpression.getValue.

Doc from javax.el.ValueExpression.getValue.

Evaluates the expression relative to the provided context, and returns the resulting value.

The resulting value is automatically coerced to the type returned by getExpectedType(), which was provided to the ExpressionFactory when this expression was created.

Parameters
elContext:ELContext

The context of this evaluation.

Returns:Object

The result of the expression evaluation.

Annotations
@Override
hashCodeback to summary
public int hashCode()

Implements abstract javax.el.Expression.hashCode.

Doc from javax.el.Expression.hashCode.

Returns the hash code for this Expression.

See the note in the equals method on how two expressions can be equal if their expression Strings are different. Recall that if two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result. Implementations must take special note and implement hashCode correctly.

Returns:int

The hash code for this Expression.

Annotations
@Override
isLiteralTextback to summary
public boolean isLiteralText()

Implements abstract javax.el.Expression.isLiteralText.

Doc from javax.el.Expression.isLiteralText.

Returns whether this expression was created from only literal text.

This method must return true if and only if the expression string this expression was created from contained no unescaped EL delimeters (${...} or #{...}).

Returns:boolean

true if this expression was created from only literal text; false otherwise.

Annotations
@Override
isReadOnlyback to summary
public boolean isReadOnly(ELContext elContext)

Implements abstract javax.el.ValueExpression.isReadOnly.

Doc from javax.el.ValueExpression.isReadOnly.

Evaluates the expression relative to the provided context, and returns true if a call to setValue will always fail.

Parameters
elContext:ELContext

The context of this evaluation.

Returns:boolean

true if the expression is read-only or false if not.

Annotations
@Override
popCompositeComponentback to summary
private void popCompositeComponent(FacesContext ctx)
pushCompositeComponentback to summary
private boolean pushCompositeComponent(FacesContext ctx)
setValueback to summary
public void setValue(ELContext elContext, Object o)

Implements abstract javax.el.ValueExpression.setValue.

Doc from javax.el.ValueExpression.setValue.

Evaluates the expression relative to the provided context, and sets the result to the provided value.

Parameters
elContext:ELContext

The context of this evaluation.

o:Object

The new value to be set.

Annotations
@Override
toStringback to summary
public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object.

Returns:String

a string representation of the object.

Annotations
@Override