Merge pull request #483 from fjtirado/Fix_#474

[Fix_#474] For task implementation

Author: fjtirado

impl/core/src/main/java/io/serverlessworkflow/impl/ContextAware.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * 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 io.serverlessworkflow.impl;
+
+import java.util.Map;
+
+public interface ContextAware {
+  Map<String, Object> variables();
+}

impl/core/src/main/java/io/serverlessworkflow/impl/DefaultWorkflowPosition.java

@@ -17,7 +17,19 @@
 
 public class DefaultWorkflowPosition implements WorkflowPosition {
 
-  private StringBuilder sb = new StringBuilder("");
+  private StringBuilder sb;
+
+  DefaultWorkflowPosition() {
+    this.sb = new StringBuilder("");
+  }
+
+  private DefaultWorkflowPosition(WorkflowPosition position) {
+    this.sb = new StringBuilder(position.toString());
+  }
+
+  public DefaultWorkflowPosition copy() {
+    return new DefaultWorkflowPosition(this);
+  }
 
   @Override
   public WorkflowPosition addIndex(int index) {

impl/core/src/main/java/io/serverlessworkflow/impl/DefaultWorkflowPositionFactory.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2020-Present The Serverless Workflow Specification Authors
+ *
+ * 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 io.serverlessworkflow.impl;
+
+class DefaultWorkflowPositionFactory implements WorkflowPositionFactory {
+
+  private static WorkflowPositionFactory instance = new DefaultWorkflowPositionFactory();
+
+  public static WorkflowPositionFactory get() {
+    return instance;
+  }
+
+  private DefaultWorkflowPositionFactory() {}
+
+  @Override
+  public WorkflowPosition buildPosition() {
+    return new DefaultWorkflowPosition();
+  }
+}

impl/core/src/main/java/io/serverlessworkflow/impl/TaskContext.java

@@ -19,28 +19,48 @@
 import io.serverlessworkflow.api.types.FlowDirective;
 import io.serverlessworkflow.api.types.FlowDirectiveEnum;
 import io.serverlessworkflow.api.types.TaskBase;
+import java.util.HashMap;
+import java.util.Map;
 
-public class TaskContext<T extends TaskBase> {
+public class TaskContext<T extends TaskBase> implements ContextAware {
 
   private final JsonNode rawInput;
   private final T task;
+  private final WorkflowPosition position;
 
   private JsonNode input;
   private JsonNode output;
   private JsonNode rawOutput;
   private FlowDirective flowDirective;
+  private Map<String, Object> contextVariables;
 
-  public TaskContext(JsonNode rawInput, T task) {
-    this.rawInput = rawInput;
+  public TaskContext(JsonNode input, WorkflowPosition position) {
+    this.rawInput = input;
+    this.position = position;
+    this.task = null;
+    this.contextVariables = new HashMap<>();
+    init();
+  }
+
+  public TaskContext(JsonNode input, TaskContext<?> taskContext, T task) {
+    this.rawInput = input;
+    this.position = taskContext.position.copy();
+    this.task = task;
+    this.flowDirective = task.getThen();
+    this.contextVariables = new HashMap<>(taskContext.variables());
+    init();
+  }
+
+  private void init() {
     this.input = rawInput;
     this.rawOutput = rawInput;
     this.output = rawInput;
-    this.task = task;
-    this.flowDirective = task.getThen();
   }
 
   public void input(JsonNode input) {
     this.input = input;
+    this.rawOutput = input;
+    this.output = input;
   }
 
   public JsonNode input() {
@@ -81,4 +101,12 @@ public FlowDirective flowDirective() {
         ? new FlowDirective().withFlowDirectiveEnum(FlowDirectiveEnum.CONTINUE)
         : flowDirective;
   }
+
+  public Map<String, Object> variables() {
+    return contextVariables;
+  }
+
+  public WorkflowPosition position() {
+    return position;
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowApplication.java

@@ -25,7 +25,6 @@
 import io.serverlessworkflow.impl.jsonschema.SchemaValidatorFactory;
 import io.serverlessworkflow.impl.resources.DefaultResourceLoaderFactory;
 import io.serverlessworkflow.impl.resources.ResourceLoaderFactory;
-
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
@@ -40,17 +39,20 @@ public class WorkflowApplication implements AutoCloseable {
   private final SchemaValidatorFactory schemaValidatorFactory;
   private final Collection<WorkflowExecutionListener> listeners;
   private final Map<WorkflowId, WorkflowDefinition> definitions;
+  private final WorkflowPositionFactory positionFactory;
 
   public WorkflowApplication(
       TaskExecutorFactory taskFactory,
       ExpressionFactory exprFactory,
       ResourceLoaderFactory resourceLoaderFactory,
       SchemaValidatorFactory schemaValidatorFactory,
+      WorkflowPositionFactory positionFactory,
       Collection<WorkflowExecutionListener> listeners) {
     this.taskFactory = taskFactory;
     this.exprFactory = exprFactory;
     this.resourceLoaderFactory = resourceLoaderFactory;
     this.schemaValidatorFactory = schemaValidatorFactory;
+    this.positionFactory = positionFactory;
     this.listeners = listeners;
     this.definitions = new ConcurrentHashMap<>();
   }
@@ -85,6 +87,7 @@ public static class Builder {
     private Collection<WorkflowExecutionListener> listeners;
     private ResourceLoaderFactory resourceLoaderFactory = DefaultResourceLoaderFactory.get();
     private SchemaValidatorFactory schemaValidatorFactory = DefaultSchemaValidatorFactory.get();
+    private WorkflowPositionFactory positionFactory = DefaultWorkflowPositionFactory.get();
 
     private Builder() {}
 
@@ -111,6 +114,11 @@ public Builder withResourceLoaderFactory(ResourceLoaderFactory resourceLoader) {
       return this;
     }
 
+    public Builder withPositionFactory(WorkflowPositionFactory positionFactory) {
+      this.positionFactory = positionFactory;
+      return this;
+    }
+
     public Builder withSchemaValidatorFactory(SchemaValidatorFactory factory) {
       this.schemaValidatorFactory = factory;
       return this;
@@ -122,6 +130,7 @@ public WorkflowApplication build() {
           exprFactory,
           resourceLoaderFactory,
           schemaValidatorFactory,
+          positionFactory,
           listeners == null
               ? Collections.emptySet()
               : Collections.unmodifiableCollection(listeners));
@@ -146,4 +155,8 @@ public void close() throws Exception {
     }
     definitions.clear();
   }
+
+  public WorkflowPositionFactory positionFactory() {
+    return positionFactory;
+  }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowContext.java

@@ -19,49 +19,16 @@
 import io.serverlessworkflow.impl.json.JsonUtils;
 
 public class WorkflowContext {
-  private final WorkflowPosition position;
   private final WorkflowDefinition definition;
   private final JsonNode input;
-  private JsonNode current;
   private JsonNode context;
 
-  private WorkflowContext(
-      WorkflowPosition position, WorkflowDefinition definition, JsonNode input) {
-    this.position = position;
+  WorkflowContext(WorkflowDefinition definition, JsonNode input) {
     this.definition = definition;
     this.input = input;
-    this.current = input.deepCopy();
     this.context = JsonUtils.mapper().createObjectNode();
   }
 
-  public static Builder builder(WorkflowDefinition definition, JsonNode input) {
-    return new Builder(definition, input);
-  }
-
-  public static class Builder {
-    private WorkflowPosition position = new DefaultWorkflowPosition();
-    private WorkflowDefinition definition;
-    private JsonNode input;
-
-    private Builder(WorkflowDefinition definition, JsonNode input) {
-      this.definition = definition;
-      this.input = input;
-    }
-
-    public Builder position(WorkflowPosition position) {
-      this.position = position;
-      return this;
-    }
-
-    public WorkflowContext build() {
-      return new WorkflowContext(position, definition, input);
-    }
-  }
-
-  public WorkflowPosition position() {
-    return position;
-  }
-
   public JsonNode context() {
     return context;
   }
@@ -74,14 +41,6 @@ public JsonNode rawInput() {
     return input;
   }
 
-  public void current(JsonNode output) {
-    this.current = output;
-  }
-
-  public JsonNode current() {
-    return current;
-  }
-
   public WorkflowDefinition definition() {
     return definition;
   }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowDefinition.java

@@ -28,7 +28,6 @@
 import io.serverlessworkflow.impl.jsonschema.SchemaValidator;
 import io.serverlessworkflow.impl.jsonschema.SchemaValidatorFactory;
 import io.serverlessworkflow.impl.resources.ResourceLoader;
-
 import java.nio.file.Path;
 import java.util.Collection;
 import java.util.Map;
@@ -47,6 +46,7 @@ public class WorkflowDefinition implements AutoCloseable {
   private final ExpressionFactory exprFactory;
   private final ResourceLoader resourceLoader;
   private final SchemaValidatorFactory schemaValidatorFactory;
+  private final WorkflowPositionFactory positionFactory;
   private final Map<String, TaskExecutor<? extends TaskBase>> taskExecutors =
       new ConcurrentHashMap<>();
 
@@ -56,12 +56,14 @@ private WorkflowDefinition(
       TaskExecutorFactory taskFactory,
       ResourceLoader resourceLoader,
       ExpressionFactory exprFactory,
-      SchemaValidatorFactory schemaValidatorFactory) {
+      SchemaValidatorFactory schemaValidatorFactory,
+      WorkflowPositionFactory positionFactory) {
     this.workflow = workflow;
     this.listeners = listeners;
     this.taskFactory = taskFactory;
     this.exprFactory = exprFactory;
     this.schemaValidatorFactory = schemaValidatorFactory;
+    this.positionFactory = positionFactory;
     this.resourceLoader = resourceLoader;
     if (workflow.getInput() != null) {
       Input input = workflow.getInput();
@@ -90,7 +92,8 @@ static WorkflowDefinition of(WorkflowApplication application, Workflow workflow,
         application.taskFactory(),
         application.resourceLoaderFactory().getResourceLoader(path),
         application.expressionFactory(),
-        application.validatorFactory());
+        application.validatorFactory(),
+        application.positionFactory());
   }
 
   public WorkflowInstance execute(Object input) {
@@ -142,6 +145,10 @@ public ResourceLoader resourceLoader() {
     return resourceLoader;
   }
 
+  public WorkflowPositionFactory positionFactory() {
+    return positionFactory;
+  }
+
   @Override
   public void close() {
     // TODO close resourcers hold for uncompleted process instances, if any

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowFilter.java

@@ -16,9 +16,8 @@
 package io.serverlessworkflow.impl;
 
 import com.fasterxml.jackson.databind.JsonNode;
-import java.util.Optional;
 
 @FunctionalInterface
 public interface WorkflowFilter {
-  JsonNode apply(WorkflowContext workflow, Optional<TaskContext<?>> task, JsonNode node);
+  JsonNode apply(WorkflowContext workflow, TaskContext<?> task, JsonNode node);
 }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowInstance.java

@@ -18,35 +18,37 @@
 import static io.serverlessworkflow.impl.json.JsonUtils.toJavaValue;
 
 import com.fasterxml.jackson.databind.JsonNode;
-import java.util.Optional;
 
 public class WorkflowInstance {
   private WorkflowState state;
   private WorkflowContext context;
+  private TaskContext<?> taskContext;
 
   WorkflowInstance(WorkflowDefinition definition, JsonNode input) {
     definition.inputSchemaValidator().ifPresent(v -> v.validate(input));
-    context = WorkflowContext.builder(definition, input).build();
+    context = new WorkflowContext(definition, input);
+    taskContext = new TaskContext<>(input, definition.positionFactory().buildPosition());
     definition
         .inputFilter()
-        .ifPresent(f -> context.current(f.apply(context, Optional.empty(), context.current())));
+        .ifPresent(f -> taskContext.input(f.apply(context, taskContext, input)));
     state = WorkflowState.STARTED;
-    WorkflowUtils.processTaskList(definition.workflow().getDo(), context);
+    taskContext.rawOutput(
+        WorkflowUtils.processTaskList(definition.workflow().getDo(), context, taskContext));
     definition
         .outputFilter()
-        .ifPresent(f -> context.current(f.apply(context, Optional.empty(), context.current())));
-    definition.outputSchemaValidator().ifPresent(v -> v.validate(context.current()));
+        .ifPresent(f -> taskContext.output(f.apply(context, taskContext, taskContext.rawOutput())));
+    definition.outputSchemaValidator().ifPresent(v -> v.validate(taskContext.output()));
   }
 
   public WorkflowState state() {
     return state;
   }
 
   public Object output() {
-    return toJavaValue(context.current());
+    return toJavaValue(taskContext.output());
   }
 
   public Object outputAsJsonNode() {
-    return context.current();
+    return taskContext.output();
   }
 }

impl/core/src/main/java/io/serverlessworkflow/impl/WorkflowPosition.java

@@ -24,4 +24,6 @@ public interface WorkflowPosition {
   WorkflowPosition addIndex(int index);
 
   WorkflowPosition back();
+
+  WorkflowPosition copy();
 }