Implements abstract com.google.escapevelocity.ExpressionNode.evaluate.

Doc from com.google.escapevelocity.ExpressionNode.evaluate.

Returns the result of evaluating this node in the given context. This result may be used as part of a further operation, for example evaluating 2 + 3 to 5 in order to set $x to 5 in #set ($x = 2 + 3). Or it may be used directly as part of the template output, for example evaluating replacing name by Fred in My name is $name..

This has to be an Object rather than a String (or rather than appending to a StringBuilder) because it can potentially participate in other operations. In the preceding example, the nodes representing 2 and 3 and the node representing 2 + 3 all return Integer. As another example, in #if ($foo.bar < 3) the value $foo is itself an ExpressionNode which evaluates to the object referenced by the foo variable, and $foo.bar is another ExpressionNode that takes the value from foo and looks for the property bar in it.

Parameters

context:EvaluationContext

the context of the evaluation, for example the $variables that are in scope

undefinedIsFalse:boolean

whether an undefined plain reference like $foo is considered to be false. This is the case when evaluating the condition in an #if. Everywhere else, an undefined reference causes an exception.

Annotations

@Override

Determines if the given argument list is compatible with the given parameter types. This includes an Integer argument being compatible with a parameter of type int or long, for example.

Implements abstract com.google.escapevelocity.ExpressionNode.evaluate.

Doc from com.google.escapevelocity.ExpressionNode.evaluate.

Returns the result of evaluating this node in the given context. This result may be used as part of a further operation, for example evaluating 2 + 3 to 5 in order to set $x to 5 in #set ($x = 2 + 3). Or it may be used directly as part of the template output, for example evaluating replacing name by Fred in My name is $name..

This has to be an Object rather than a String (or rather than appending to a StringBuilder) because it can potentially participate in other operations. In the preceding example, the nodes representing 2 and 3 and the node representing 2 + 3 all return Integer. As another example, in #if ($foo.bar < 3) the value $foo is itself an ExpressionNode which evaluates to the object referenced by the foo variable, and $foo.bar is another ExpressionNode that takes the value from foo and looks for the property bar in it.

Evaluating a method expression such as $x.foo($y) involves looking at the actual types of $x and $y. The type of $x must have a public method foo with a parameter type that is compatible with $y.

Currently we don't allow there to be more than one matching method. That is a difference from Velocity, which blithely allows you to invoke List#remove(int) even though it can't really know that you didn't mean to invoke List#remove(Object) with an Object that just happens to be an Integer.

The method to be invoked must be visible in a public class or interface that is either the class of $x itself or one of its supertypes. Allowing supertypes is important because you may want to invoke a public method like List#size() on a list whose class is not public, such as the list returned by java.util.Collections#singletonList.

Parameters

context:EvaluationContext

the context of the evaluation, for example the $variables that are in scope

undefinedIsFalse:boolean

whether an undefined plain reference like $foo is considered to be false. This is the case when evaluating the condition in an #if. Everywhere else, an undefined reference causes an exception.

Annotations

@Override

Returns true if from can be assigned to to according to Widening Primitive Conversion.