freemarker.template.expression
Class ListRange

java.lang.Object
  freemarker.template.expression.ListRange

All Implemented Interfaces:

Expression, java.io.Serializable

public final class ListRange
extends java.lang.Object
implements Expression, java.io.Serializable

An expression that represents a indexModel of list values. The from and to expressions are held until evaluation time, then a FastListRange is created. A simple FastIndexedIterator is used to iterate over the values.

Since:

1.8

Version:

$Id: ListRange.java 1153 2013-04-15 10:59:37Z run2000 $

See Also:

Serialized Form

Constructor Summary

ListRange(Expression fromRange, Expression toRange)
Constructor that takes from and to values in the form of expressions.

Method Summary

boolean	equals(java.lang.Object o) Determines whether this object is equal to the given object.
TemplateModel	getAsTemplateModel(TemplateWriteableHashModel modelRoot) Retrieve the list range as a template model.
java.util.Set<ExpressionUtils.ExpressionType>	getType() Determine the type of result that can be calculated by this expression.
int	hashCode() Returns the hash code for this operator.
boolean	isComplete() Do we have from and to values?
boolean	isConstant() Determine whether result calculated by this expression is a constant value.
Expression	resolveExpression() Resolves the current expression, possibly into a different expression object.
java.lang.String	toString() Returns a string representation of the object.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ListRange

public ListRange(Expression fromRange,
                 Expression toRange)

Constructor that takes from and to values in the form of expressions. The expressions are evaluated at template run time and converted into values usable by the FastListRange.

Parameters:

fromRange - the start of the range, as an expression

toRange - the end of the range, as an expression

Throws:

java.lang.NullPointerException - fromRange or toRange are null

java.lang.IllegalArgumentException - the expressions cannot be evaluated as numbers

Method Detail

getAsTemplateModel

public TemplateModel getAsTemplateModel(TemplateWriteableHashModel modelRoot)
                                 throws TemplateException

Retrieve the list range as a template model.

Specified by:

getAsTemplateModel in interface Expression

Parameters:

modelRoot - the model from which to evaluate the range of the list

Returns:

a new FastListRange representing the range list

Throws:

TemplateException - the new range could not be created

isComplete

public boolean isComplete()

Do we have from and to values?

Specified by:

isComplete in interface Expression

Returns:

true if both from and to values are specified, otherwise false

getType

public java.util.Set<ExpressionUtils.ExpressionType> getType()

Determine the type of result that can be calculated by this expression. This is in the form of an integer constant ored together from values in the ExpressionUtils class.

Specified by:

getType in interface Expression

isConstant

public boolean isConstant()

Determine whether result calculated by this expression is a constant value.

Specified by:

isConstant in interface Expression

toString

public java.lang.String toString()

Returns a string representation of the object.

Overrides:

toString in class java.lang.Object

Returns:

a String representation of this expression

equals

public boolean equals(java.lang.Object o)

Determines whether this object is equal to the given object.

Overrides:

equals in class java.lang.Object

Parameters:

o - the object to be compared with

Returns:

true if the objects are equal, otherwise false

hashCode

public int hashCode()

Returns the hash code for this operator.

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code of this object

resolveExpression

public Expression resolveExpression()
                             throws TemplateException

Resolves the current expression, possibly into a different expression object. This is loosely equivalent to the serialization protocol's readResolve method. Situations where this may be used are:

• Caching frequently-used expression objects
• Evaluating constant expressions, and returning a constant reference

Specified by:

resolveExpression in interface Expression

Throws:

TemplateException