/*
* Copyright 2011-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.services.stepfunctions.builder.states;
import com.amazonaws.services.stepfunctions.builder.ErrorCodes;
import com.amazonaws.services.stepfunctions.builder.internal.Buildable;
import com.amazonaws.services.stepfunctions.builder.internal.PropertyNames;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonUnwrapped;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* A Choice state adds branching logic to a state machine. A Choice state consists of a list of choices, each of which contains a
* potential transition state and a condition that determines if that choice is evaluated, and a default state that the state
* machine transitions to if no choice branches are matched.
*
* @see <a href="https://states-language.net/spec.html#choice-state>https://states-language.net/spec.html#choice-state</a>
*/
public final class ChoiceState implements State {
@JsonProperty(PropertyNames.COMMENT)
private final String comment;
@JsonProperty(PropertyNames.DEFAULT_STATE)
private final String defaultStateName;
@JsonProperty(PropertyNames.CHOICES)
private final List<Choice> choices;
@JsonUnwrapped
private final PathContainer pathContainer;
private ChoiceState(Builder builder) {
this.comment = builder.comment;
this.defaultStateName = builder.defaultStateName;
this.choices = Buildable.Utils.build(builder.choices);
this.pathContainer = builder.pathContainer.build();
}
/**
* @return Type identifier of {@link ChoiceState}.
*/
@Override
public String getType() {
return "Choice";
}
/**
* @return Human readable description for the state.
*/
public String getComment() {
return comment;
}
/**
* @return Name of state to transition to if no {@link Choice} rules match.
*/
public String getDefaultStateName() {
return defaultStateName;
}
/**
* @return The choice rules for this state.
*/
public List<Choice> getChoices() {
return choices;
}
/**
* @return The input path expression that may optionally transform the input to this state.
*/
@JsonIgnore
public String getInputPath() {
return pathContainer.getInputPath();
}
/**
* @return The output path expression that may optionally transform the output to this state.
*/
@JsonIgnore
public String getOutputPath() {
return pathContainer.getOutputPath();
}
/**
* Choice state can never be a terminal state.
*
* @return False.
*/
@Override
public boolean isTerminalState() {
return false;
}
@Override
public <T> T accept(StateVisitor<T> visitor) {
return visitor.visit(this);
}
/**
* @return Builder instance to construct a {@link ChoiceState}.
*/
public static Builder builder() {
return new Builder();
}
/**
* Builder for a {@link ChoiceState}.
*/
public static final class Builder implements State.Builder, InputOutputPathBuilder<Builder> {
@JsonProperty(PropertyNames.COMMENT)
private String comment;
@JsonProperty(PropertyNames.DEFAULT_STATE)
private String defaultStateName;
@JsonProperty(PropertyNames.CHOICES)
private List<Choice.Builder> choices = new ArrayList<Choice.Builder>();
private final PathContainer.Builder pathContainer = PathContainer.builder();
private Builder() {
}
/**
* OPTIONAL. Human readable description for the state.
*
* @param comment New comment.
* @return This object for method chaining.
*/
public Builder comment(String comment) {
this.comment = comment;
return this;
}
/**
* OPTIONAL. Name of state to transition to if no {@link Choice} rules match. If a default state is not provided and no
* choices match then a {@link ErrorCodes#NO_CHOICE_MATCHED} error is thrown.
*
* @param defaultStateName Name of default state.
* @return This object for method chaining.
*/
public Builder defaultStateName(String defaultStateName) {
this.defaultStateName = defaultStateName;
return this;
}
/**
* REQUIRED. Adds a new {@link Choice} rule to the {@link ChoiceState}. A {@link ChoiceState} must contain at least one
* choice rule.
*
* @param choiceBuilder Instance of {@link com.amazonaws.services.stepfunctions.builder.states.Choice.Builder}. Note that
* the {@link
* Choice} object is not built until the {@link ChoiceState} is built so any modifications on the
* state builder will be reflected in this object.
* @return This object for method chaining.
*/
public Builder choice(Choice.Builder choiceBuilder) {
this.choices.add(choiceBuilder);
return this;
}
/**
* REQUIRED. Adds the {@link Choice} rules to the {@link ChoiceState}. A {@link ChoiceState} must contain at least one
* choice rule.
*
* @param choiceBuilders Instances of {@link com.amazonaws.services.stepfunctions.builder.states.Choice.Builder}. Note
* that the {@link
* Choice} object is not built until the {@link ChoiceState} is built so any modifications on the
* state builder will be reflected in this object.
* @return This object for method chaining.
*/
public Builder choices(Choice.Builder... choiceBuilders) {
Collections.addAll(this.choices, choiceBuilders);
return this;
}
@Override
public Builder inputPath(String inputPath) {
pathContainer.inputPath(inputPath);
return this;
}
@Override
public Builder outputPath(String outputPath) {
pathContainer.outputPath(outputPath);
return this;
}
/**
* @return An immutable {@link ChoiceState} object.
*/
public ChoiceState build() {
return new ChoiceState(this);
}
}
}