org.geomajas.service

Interface FeatureExpressionService

@Api(allMethods=true)
public interface FeatureExpressionService

This service evaluates feature expressions for InternalFeature objects. Expressions are textual and expressed in a language that depends on the specific implementation of this service. The default implementation uses the Spring Expression Language (SpEL), but other implementations may be based on eg. Freemarker/Velocity templates or even a custom language. As a minimal requirement, the language should be able to evaluate simple references to primitive attribute values.

Since:

1.10.0

Author:

Jan De Moerloose

Method Summary

Methods

Modifier and Type	Method and Description
Object	evaluate(String expression, InternalFeature feature) Evaluates the specified expression for the specified feature.
void	setVariables(Map<String,Object> variables) Adds a map of variables to the expression context.

Method Detail

evaluate

Object evaluate(String expression,
              InternalFeature feature)
                throws LayerException

Evaluates the specified expression for the specified feature. Evaluation may involve attribute access, which is subject to security limitations.

Parameters:

expression - the expression to be evaluated (see class implementation)

feature - the internal feature

Returns:

the expression value

Throws:

LayerException - expression was invalid or could not be evaluated on this feature

setVariables

void setVariables(Map<String,Object> variables)

Adds a map of variables to the expression context. The specified key will be used as the name to refer to this variable in the expression (using the conventions of the expression language for referencing it). Variables and their exposed methods should be thread-safe.

Parameters:

variables - map of named variables