[Fix serverlessworkflow#463] Supporting runtime expressions

Signed-off-by: Francisco Javier Tirado Sarti <[email protected]>

impl/core/pom.xml

@@ -15,6 +15,11 @@
       <artifactId>serverlessworkflow-api</artifactId>
       <version>7.0.0-SNAPSHOT</version>
     </dependency>
+    <dependency>
+      <groupId>com.github.f4b6a3</groupId>
+      <artifactId>ulid-creator</artifactId>
+      <version>5.2.3</version>
+    </dependency>
     <dependency>
      <groupId>com.networknt</groupId>
      <artifactId>json-schema-validator</artifactId>

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

@@ -27,6 +27,6 @@ private DefaultWorkflowPositionFactory() {}
 
   @Override
   public WorkflowPosition buildPosition() {
-    return new DefaultWorkflowPosition();
+    return new ListWorkflowPosition();
   }
 }

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

@@ -0,0 +1,70 @@
+/*
+ * 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.Deque;
+import java.util.LinkedList;
+import java.util.stream.Collectors;
+
+public class ListWorkflowPosition implements WorkflowPosition {
+
+  private Deque<Object> list;
+
+  ListWorkflowPosition() {
+    this(new LinkedList<>());
+  }
+
+  private ListWorkflowPosition(Deque<Object> list) {
+    this.list = list;
+  }
+
+  public ListWorkflowPosition copy() {
+    return new ListWorkflowPosition(this.list);
+  }
+
+  @Override
+  public WorkflowPosition addIndex(int index) {
+    list.add(index);
+    return this;
+  }
+
+  @Override
+  public WorkflowPosition addProperty(String prop) {
+    list.add(prop);
+    return this;
+  }
+
+  @Override
+  public String jsonPointer() {
+    return list.stream().map(Object::toString).collect(Collectors.joining("/"));
+  }
+
+  @Override
+  public String toString() {
+    return "ListWorkflowPosition [list=" + list + "]";
+  }
+
+  @Override
+  public WorkflowPosition back() {
+    list.removeLast();
+    return this;
+  }
+
+  @Override
+  public Object last() {
+    return list.pollLast();
+  }
+}

impl/core/src/main/java/io/serverlessworkflow/impl/RuntimeDescriptorFactory.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 io.serverlessworkflow.impl.expressions.RuntimeDescriptor;
+import java.util.function.Supplier;
+
+@FunctionalInterface
+public interface RuntimeDescriptorFactory extends Supplier<RuntimeDescriptor> {}

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

@@ -15,20 +15,20 @@
  */
 package io.serverlessworkflow.impl;
 
-public class DefaultWorkflowPosition implements WorkflowPosition {
+public class StringBufferWorkflowPosition implements WorkflowPosition {
 
   private StringBuilder sb;
 
-  DefaultWorkflowPosition() {
-    this.sb = new StringBuilder("");
+  StringBufferWorkflowPosition() {
+    this("");
   }
 
-  private DefaultWorkflowPosition(WorkflowPosition position) {
-    this.sb = new StringBuilder(position.toString());
+  private StringBufferWorkflowPosition(String str) {
+    this.sb = new StringBuilder(str);
   }
 
-  public DefaultWorkflowPosition copy() {
-    return new DefaultWorkflowPosition(this);
+  public StringBufferWorkflowPosition copy() {
+    return new StringBufferWorkflowPosition(this.jsonPointer());
   }
 
   @Override
@@ -50,7 +50,7 @@ public String jsonPointer() {
 
   @Override
   public String toString() {
-    return "DefaultWorkflowPosition [sb=" + sb + "]";
+    return "StringBufferWorkflowPosition [sb=" + sb + "]";
   }
 
   @Override
@@ -61,4 +61,10 @@ public WorkflowPosition back() {
     }
     return this;
   }
+
+  @Override
+  public Object last() {
+    int indexOf = sb.lastIndexOf("/");
+    return indexOf != -1 ? jsonPointer().substring(indexOf + 1) : "";
+  }
 }

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

@@ -19,6 +19,7 @@
 import io.serverlessworkflow.api.types.FlowDirective;
 import io.serverlessworkflow.api.types.FlowDirectiveEnum;
 import io.serverlessworkflow.api.types.TaskBase;
+import java.time.Instant;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -27,6 +28,7 @@ public class TaskContext<T extends TaskBase> {
   private final JsonNode rawInput;
   private final T task;
   private final WorkflowPosition position;
+  private final Instant startedAt = Instant.now();
 
   private JsonNode input;
   private JsonNode output;
@@ -109,4 +111,8 @@ public Map<String, Object> variables() {
   public WorkflowPosition position() {
     return position;
   }
+
+  public Instant startedAt() {
+    return startedAt;
+  }
 }

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

@@ -0,0 +1,34 @@
+/*
+ * 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 com.github.f4b6a3.ulid.UlidCreator;
+
+public class ULIDFactory implements WorkflowIdFactory {
+
+  private static ULIDFactory instance = new ULIDFactory();
+
+  public static WorkflowIdFactory get() {
+    return instance;
+  }
+
+  private ULIDFactory() {}
+
+  @Override
+  public String id() {
+    return UlidCreator.getMonotonicUlid().toString();
+  }
+}

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

@@ -21,6 +21,7 @@
 import io.serverlessworkflow.impl.executors.TaskExecutorFactory;
 import io.serverlessworkflow.impl.expressions.ExpressionFactory;
 import io.serverlessworkflow.impl.expressions.JQExpressionFactory;
+import io.serverlessworkflow.impl.expressions.RuntimeDescriptor;
 import io.serverlessworkflow.impl.jsonschema.DefaultSchemaValidatorFactory;
 import io.serverlessworkflow.impl.jsonschema.SchemaValidatorFactory;
 import io.serverlessworkflow.impl.resources.DefaultResourceLoaderFactory;
@@ -37,22 +38,28 @@ public class WorkflowApplication implements AutoCloseable {
   private final ExpressionFactory exprFactory;
   private final ResourceLoaderFactory resourceLoaderFactory;
   private final SchemaValidatorFactory schemaValidatorFactory;
+  private final WorkflowIdFactory idFactory;
   private final Collection<WorkflowExecutionListener> listeners;
   private final Map<WorkflowId, WorkflowDefinition> definitions;
   private final WorkflowPositionFactory positionFactory;
+  private final RuntimeDescriptorFactory runtimeDescriptorFactory;
 
   public WorkflowApplication(
       TaskExecutorFactory taskFactory,
       ExpressionFactory exprFactory,
       ResourceLoaderFactory resourceLoaderFactory,
       SchemaValidatorFactory schemaValidatorFactory,
       WorkflowPositionFactory positionFactory,
+      WorkflowIdFactory idFactory,
+      RuntimeDescriptorFactory runtimeDescriptorFactory,
       Collection<WorkflowExecutionListener> listeners) {
     this.taskFactory = taskFactory;
     this.exprFactory = exprFactory;
     this.resourceLoaderFactory = resourceLoaderFactory;
     this.schemaValidatorFactory = schemaValidatorFactory;
     this.positionFactory = positionFactory;
+    this.idFactory = idFactory;
+    this.runtimeDescriptorFactory = runtimeDescriptorFactory;
     this.listeners = listeners;
     this.definitions = new ConcurrentHashMap<>();
   }
@@ -81,13 +88,20 @@ public Collection<WorkflowExecutionListener> listeners() {
     return listeners;
   }
 
+  public WorkflowIdFactory idFactory() {
+    return idFactory;
+  }
+
   public static class Builder {
     private TaskExecutorFactory taskFactory = DefaultTaskExecutorFactory.get();
     private ExpressionFactory exprFactory = JQExpressionFactory.get();
     private Collection<WorkflowExecutionListener> listeners;
     private ResourceLoaderFactory resourceLoaderFactory = DefaultResourceLoaderFactory.get();
     private SchemaValidatorFactory schemaValidatorFactory = DefaultSchemaValidatorFactory.get();
     private WorkflowPositionFactory positionFactory = DefaultWorkflowPositionFactory.get();
+    private WorkflowIdFactory idFactory = ULIDFactory.get();
+    private RuntimeDescriptorFactory descriptorFactory =
+        () -> new RuntimeDescriptor("reference impl", "1.0.0_alpha", Collections.emptyMap());
 
     private Builder() {}
 
@@ -124,13 +138,25 @@ public Builder withSchemaValidatorFactory(SchemaValidatorFactory factory) {
       return this;
     }
 
+    public Builder withIdFactory(WorkflowIdFactory factory) {
+      this.idFactory = factory;
+      return this;
+    }
+
+    public Builder withDescriptorFactory(RuntimeDescriptorFactory factory) {
+      this.descriptorFactory = factory;
+      return this;
+    }
+
     public WorkflowApplication build() {
       return new WorkflowApplication(
           taskFactory,
           exprFactory,
           resourceLoaderFactory,
           schemaValidatorFactory,
           positionFactory,
+          idFactory,
+          descriptorFactory,
           listeners == null
               ? Collections.emptySet()
               : Collections.unmodifiableCollection(listeners));
@@ -159,4 +185,8 @@ public void close() throws Exception {
   public WorkflowPositionFactory positionFactory() {
     return positionFactory;
   }
+
+  public RuntimeDescriptorFactory runtimeDescriptorFactory() {
+    return runtimeDescriptorFactory;
+  }
 }

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

@@ -16,29 +16,26 @@
 package io.serverlessworkflow.impl;
 
 import com.fasterxml.jackson.databind.JsonNode;
-import io.serverlessworkflow.impl.json.JsonUtils;
 
 public class WorkflowContext {
   private final WorkflowDefinition definition;
-  private final JsonNode input;
-  private JsonNode context;
+  private final WorkflowInstance instance;
 
-  WorkflowContext(WorkflowDefinition definition, JsonNode input) {
+  WorkflowContext(WorkflowDefinition definition, WorkflowInstance instance) {
     this.definition = definition;
-    this.input = input;
-    this.context = JsonUtils.mapper().createObjectNode();
+    this.instance = instance;
   }
 
-  public JsonNode context() {
-    return context;
+  public WorkflowInstance instance() {
+    return instance;
   }
 
-  public void context(JsonNode context) {
-    this.context = context;
+  public JsonNode context() {
+    return instance.context();
   }
 
-  public JsonNode rawInput() {
-    return input;
+  public void context(JsonNode context) {
+    this.instance.context(context);
   }
 
   public WorkflowDefinition definition() {