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1 package org.jicengine.element.impl;
2
3 import java.util.Arrays  ;
4
5 import org.jicengine.element.ActionElement;
6 import org.jicengine.element.Element;
7 import org.jicengine.element.ElementCompiler;
8 import org.jicengine.element.ElementException;
9 import org.jicengine.element.Location;
10 import org.jicengine.element.VariableElement;
11 import org.jicengine.expression.ClassParser;
12 import org.jicengine.operation.Context;
13 import org.jicengine.operation.Operation;
14 import org.jicengine.operation.OperationException;
15 import org.jicengine.operation.ReflectionUtils;
16
17 public class ConstantOfElementCompiler extends ElementCompiler {
18
19 public ConstantOfElementCompiler(String name, Location location, String [] parameters) throws ElementException
20 {
21 super(name, location);
22
23 if( parameters.length == 1){
24 try {
25 Class ownerClass = ClassParser.toClass(parameters[0]);
26 getElement().setConstructor(new ConstantOfConstructor(ownerClass));
27 } catch (ClassNotFoundException e){
28 throw new ElementException("Owner class not found",e, getName(), getLocation());
29 }
30 }
31 else {
32 throw new ElementException("Expected 1 parameter, got " + parameters.length + " parameters: " + Arrays.asList(parameters), getName(),getLocation());
33 }
34 }
35
36 protected ActionElement handleLooseVariableElement(VariableElement child) throws ElementException
37 {
38 throw new ElementException("Child elements not allowed", getName(), getLocation());
39 }
40
41 public class ConstantOfConstructor implements Operation {
42
43 private Class ownerClass;
44
45 public ConstantOfConstructor(Class ownerClass)
46 {
47 this.ownerClass = ownerClass;
48 }
49
50 public Object execute(Context context) throws OperationException
51 {
52 try {
53 String fieldName = (String ) context.getObject(Element.VARIABLE_NAME_CDATA);
54 return getConstantValue(this.ownerClass, fieldName);
55 } catch (Exception e){
56 throw new OperationException(e.getMessage(), e);
57 }
58 }
59
60 public boolean needsParameter(String name)
61 {
62 return name.equals(Element.VARIABLE_NAME_CDATA);
63 }
64
65 public boolean needsParameters()
66 {
67 return true;
68 }
69 }
70
71 public static Object getConstantValue(Class ownerClass, String fieldName) throws Exception
72 {
73 return ReflectionUtils.getFieldValue(null, ownerClass, fieldName);
74 }
75 }
76 |
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