Allow expressions in process variables (#3745)

* Allow expressions in process variables

* Expressions in process variables minor fixes

activiti-core/activiti-spring-process-extensions/src/main/java/org/activiti/spring/process/variable/types/DateVariableType.java

@@ -16,7 +16,6 @@
 package org.activiti.spring.process.variable.types;
 
 import java.util.List;
-
 import org.activiti.common.util.DateFormatterProvider;
 import org.activiti.engine.ActivitiException;
 
@@ -41,6 +40,9 @@ public class DateVariableType extends JavaObjectVariableType {
     public Object parseFromValue(Object value) throws ActivitiException {
 
         try {
+            if (isExpression(value)) {
+                return value;
+            }
             return dateFormatterProvider.toDate(value);
         } catch (Exception e) {
             throw new ActivitiException("Error parsing date value " + value, e);

activiti-core/activiti-spring-process-extensions/src/main/java/org/activiti/spring/process/variable/types/JavaObjectVariableType.java

@@ -42,9 +42,9 @@ public class JavaObjectVariableType extends VariableType {
     }
 
     @Override
-    public void validate(Object var,List<ActivitiException> errors) {
+    public void validate(Object var, List<ActivitiException> errors) {
 
-        if (var != null && !(var).getClass().isAssignableFrom(clazz)) {
+        if (var != null && !(var).getClass().isAssignableFrom(clazz) && !isExpression(var)) {
             String message = var.getClass() + " is not assignable from " + clazz;
             errors.add(new ActivitiException(message));
             logger.error(message);

activiti-core/activiti-spring-process-extensions/src/main/java/org/activiti/spring/process/variable/types/VariableType.java

@@ -16,15 +16,16 @@
 package org.activiti.spring.process.variable.types;
 
 import java.util.List;
-
+import java.util.Objects;
+import java.util.regex.Pattern;
 import org.activiti.engine.ActivitiException;
 
 /**
- * Base variable type for types as defined in extension json files.
- * Used to validate variables against definition.
+ * Base variable type for types as defined in extension json files. Used to validate variables against definition.
  */
 public abstract class VariableType {
 
+    private static final Pattern EXPRESSION_PATTERN = Pattern.compile("^\\$\\{(.|\\n)*[\\}]$");
     private String name;
 
     public String getName() {
@@ -40,4 +41,8 @@ public abstract class VariableType {
     public Object parseFromValue(Object value) throws ActivitiException {
         return value;
     }
+
+    protected boolean isExpression(Object var) {
+        return Objects.nonNull(var) && var.getClass().isAssignableFrom(String.class) && EXPRESSION_PATTERN.matcher((CharSequence) var).matches();
+    }
 }

activiti-core/activiti-spring-process-extensions/src/test/java/org/activiti/spring/process/variable/types/DateVariableTypeTest.java

+/*
+ * Copyright 2010-2020 Alfresco Software, Ltd.
+ *
+ * Licensed 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.activiti.spring.process.variable.types;
+
+import static org.assertj.core.api.Assertions.catchThrowable;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import org.activiti.common.util.DateFormatterProvider;
+import org.activiti.engine.ActivitiException;
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class DateVariableTypeTest {
+
+    private DateFormatterProvider provider = new DateFormatterProvider("yyyy-MM-dd[['T']HH:mm:ss[.SSS'Z']]");
+    private List<ActivitiException> exceptionList;
+    DateVariableType dateVariableType;
+
+    @BeforeEach
+    public void setUp() {
+        dateVariableType = new DateVariableType(Date.class, provider);
+        exceptionList = new ArrayList<>();
+    }
+
+    @Test
+    public void should_returnDate_when_parseValidString() {
+        Object result = dateVariableType.parseFromValue("1985-10-26T01:22:00.001Z");
+
+        assertTrue(result.getClass().getName().equals(Date.class.getName()));
+    }
+
+    @Test
+    public void should_throwException_when_parseInvalidString() {
+        Throwable thrown = catchThrowable(() -> dateVariableType.parseFromValue("${now()"));
+
+        Assertions.assertThat(thrown)
+            .isInstanceOf(ActivitiException.class)
+            .hasMessage("Error parsing date value ${now()");
+    }
+
+    @Test
+    public void should_returnExpressionString_when_parseValidExpression() {
+        String expression = "${now()}";
+        Object result = dateVariableType.parseFromValue(expression);
+
+        assertTrue(result.equals(expression));
+    }
+}

activiti-core/activiti-spring-process-extensions/src/test/java/org/activiti/spring/process/variable/types/JavaObjectVariableTypeTest.java

+/*
+ * Copyright 2010-2020 Alfresco Software, Ltd.
+ *
+ * Licensed 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.activiti.spring.process.variable.types;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.ArrayList;
+import java.util.List;
+import org.activiti.engine.ActivitiException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class JavaObjectVariableTypeTest {
+
+    private List<ActivitiException> exceptionList;
+    JavaObjectVariableType javaObjectVariableType;
+
+    @BeforeEach
+    public void setUp() {
+        javaObjectVariableType = new JavaObjectVariableType(Boolean.class);
+        exceptionList = new ArrayList<>();
+    }
+
+    @Test
+    public void should_returnException_when_validateValueNotAssignableToClass() {
+        javaObjectVariableType.validate(1, exceptionList);
+
+        assertTrue(exceptionList.stream().anyMatch(error ->
+            error.getMessage().equals("class java.lang.Integer is not assignable from class java.lang.Boolean")
+        ));
+    }
+
+    @Test
+    public void should_returnEmptyErrorList_when_validateValueAssignableToClass() {
+        javaObjectVariableType.validate(true, exceptionList);
+
+        assertTrue(exceptionList.isEmpty());
+    }
+
+    @Test
+    public void should_returnEmptyErrorList_when_validateValidExpression() {
+        javaObjectVariableType.validate("${now()}", exceptionList);
+
+        assertTrue(exceptionList.isEmpty());
+    }
+
+    @Test
+    public void should_returnException_when_validateIncompleteExpression() {
+        javaObjectVariableType.validate("${now()", exceptionList);
+
+        assertTrue(exceptionList.stream().anyMatch(error ->
+            error.getMessage().equals("class java.lang.String is not assignable from class java.lang.Boolean")
+        ));
+    }
+}

activiti-core/activiti-spring-process-extensions/src/test/java/org/activiti/spring/process/variable/types/JsonObjectVariableTypeTest.java

+/*
+ * Copyright 2010-2020 Alfresco Software, Ltd.
+ *
+ * Licensed 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.activiti.spring.process.variable.types;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import java.util.ArrayList;
+import java.util.List;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.activiti.engine.ActivitiException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class JsonObjectVariableTypeTest {
+
+    private List<ActivitiException> exceptionList;
+    JsonObjectVariableType jsonObjectVariableType;
+
+    @BeforeEach
+    public void setUp() {
+        jsonObjectVariableType = new JsonObjectVariableType(new ObjectMapper());
+        exceptionList = new ArrayList<>();
+    }
+
+    @Test
+    public void should_returnException_when_validateValueNotAssignableToClass() {
+        jsonObjectVariableType.validate("${now()}", exceptionList);
+
+        assertTrue(exceptionList.isEmpty());
+    }
+
+}