Author: ate
Date: Fri Jan 17 15:08:00 2014
New Revision: 1559129
URL: http://svn.apache.org/r1559129
Log:
SCXML-186: Goovy Expression evaluator support
- Groovy Script base class for SCXML providing SCXML builtin functions In() and
Data() as well as convenient functions empty() and var()
Added:
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
(with props)
Added:
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
URL:
http://svn.apache.org/viewvc/commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java?rev=1559129&view=auto
==============================================================================
---
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
(added)
+++
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
Fri Jan 17 15:08:00 2014
@@ -0,0 +1,146 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.scxml2.env.groovy;
+
+import java.lang.reflect.Array;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.commons.scxml2.Builtin;
+import org.apache.commons.scxml2.model.TransitionTarget;
+
+import groovy.lang.Binding;
+import groovy.lang.MissingPropertyException;
+import groovy.lang.Script;
+
+/**
+ * Groovy {@link Script} base class for SCXML, providing the standard
'builtin' functions {@link #In(String)} and {@link #Data(Object, String)}
+ * as well as JEXL like convenience functions {@link #empty(Object)} and
{@link #var(String)}.
+ */
+public abstract class GroovySCXMLScript extends Script {
+
+ GroovyContext context;
+ GroovyContextBinding binding;
+
+ protected GroovySCXMLScript() {
+ super(null);
+ }
+
+ @Override
+ public void setBinding(final Binding binding) {
+ super.setBinding(binding);
+ this.binding = (GroovyContextBinding)binding;
+ this.context = this.binding.getContext();
+ }
+
+ /**
+ * Gets the ALL_NAMESPACES map from context.
+ * @return the ALL_NAMESPACES map
+ */
+ @SuppressWarnings("unchecked")
+ private Map<String, String> getNamespaces() {
+ return (Map<String, String>) context.get("_ALL_NAMESPACES");
+ }
+
+ /**
+ * Gets the ALL_STATES set from context.
+ * @return the ALL_STATES set
+ */
+ @SuppressWarnings("unchecked")
+ private Set<TransitionTarget> getAllStates() {
+ return (Set<TransitionTarget>) context.get("_ALL_STATES");
+ }
+
+ /**
+ * Implements the Data() predicate for SCXML documents ( see Builtin#data
).
+ * @param data the context node
+ * @param path the XPath expression
+ * @return the first node matching the path
+ */
+ public Object Data(final Object data, final String path) {
+ // first call maps delegates to dataNode(), subsequent ones to data()
+ if (context.isEvaluatingLocation()) {
+ context.setEvaluatingLocation(false);
+ return Builtin.dataNode(getNamespaces(), data, path);
+ } else {
+ return Builtin.data(getNamespaces(), data, path);
+ }
+ }
+
+ /**
+ * Implements the In() predicate for SCXML documents ( see
Builtin#isMember )
+ * @param state The State ID to compare with
+ * @return Whether this State belongs to this Set
+ */
+ public boolean In(final String state) {
+ return Builtin.isMember(getAllStates(), state);
+ }
+
+ /**
+ * The var function can be used to check if a variable is defined,
+ * <p>
+ * In the Groovy language (implementation) you cannot check for an
undefined variable directly:
+ * Groovy will raise a MissingPropertyException before you get the chance.
+ * </p>
+ * <p>
+ * The var function works around this by indirectly looking up the
variable, which you therefore have to specify as a String.
+ * </p>
+ * <p>
+ * So, use <code>var('name')</code>, not <code>var(name)</code>
+ * </p>
+ * <p>
+ * Note: this function doesn't support object navigation, like
<code>var('name.property')</code>.<br/>
+ * Instead, once you established a variable 'name' exists, you
<em>thereafter</em> can use the standard Groovy
+ * Safe Navigation operator (?.), like so:
<code>name?.property</code>.<br/>
+ * See for more information: <a
href="http://docs.codehaus.org/display/GROOVY/Operators#Operators-SafeNavigationOperator(?.)">Groovy
SafeNavigationOperator</a>
+ * </p>
+ */
+ public boolean var(String property) {
+ if (!context.has(property)) {
+ try {
+ getMetaClass().getProperty(this, property);
+ } catch (MissingPropertyException e) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * The empty function mimics the behavior of the JEXL empty function, in
that it returns true if the parameter is:
+ * <ul>
+ * <li>null, or</li>
+ * <li>an empty String, or</li>
+ * <li>an zero length Array, or</li>
+ * <li>an empty Collection, or</li>
+ * <li>an empty Map</li>
+ * </ul>
+ * <p>
+ * Note: one difference with the JEXL language is that Groovy doesn't
allow checking for undefined variables.<br/>
+ * Before being able to check, Groovy will already have raised an
MissingPropertyException if the variable cannot be found.<br/>
+ * To work around this, the custom {@link #var(String)} function is
available.
+ * </p>
+ */
+ public boolean empty(Object obj) {
+ return obj == null ||
+ (obj instanceof String && ((String)obj).isEmpty()) ||
+ ((obj.getClass().isArray() && Array.getLength(obj)==0)) ||
+ (obj instanceof Collection && ((Collection)obj).size()==0) ||
+ (obj instanceof Map && ((Map)obj).isEmpty());
+ }
+}
Propchange:
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
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Propchange:
commons/proper/scxml/trunk/src/main/java/org/apache/commons/scxml2/env/groovy/GroovySCXMLScript.java
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