Model Citizen

Model Citizen is an annotation based model factory for Java, inspired by FactoryGirl

A Model is mapped by a @Blueprint using annotated fields. Blueprints contain default values and references to other @Blueprinted models. The ModelFactory can create models based on registered blueprints. A model already created can be passed into the ModelFactory as a reference model, which will be used as the basis for the new Model.

https://github.com/mguymon/model-citizen

JavaDoc

Install

<dependency>
  <groupId>com.tobedevoured.modelcitizen</groupId>
  <artifactId>core</artifactId>
  <version>0.8.2</version>
</dependency>

Blueprint

A blueprint is a Class annotated with @Blueprint( Class ) and contains annotated fields. Everything else is ignored by the ModelFactory. Model Citizen own blueprints are a great example of how they work.

@Blueprint: Class annotation

• value: [Class] The target model class for this blueprint.
• template: [Class] The template use to construct and inject the model. Defaults to JavaBeanTemplate

Field Annotations

@Default: The default value for the field.

• force: [boolean] Force the value of the Default to always be set, even if the target field already has a value. Default is false. This is useful for overriding primatives or Collections.

@Mapped: The value is mapped to another @Blueprint, default is the blueprint for matching field's Class. Mapped class can be set by the target param.

@MappedList: Creates a List of Models mapped to another blueprint.

• size: [int] Number of Models to be created by the ModelFactory and added to List, defaults to 1.
• target: [Class] The target Blueprint Class used to create Models
• targetList: [Class] The List created, defaults to ArrayList
• ignoreEmpty: [boolean] If true, do not create Models for an empty Set. Defaults to true.
• force: [boolean] Force the value of the MappedList to always be set, even if the target field already has a value. Default is false.

@MappedSet: Creates a Set of Models mapped to another blueprint.

• size: [int] Number of Models to be created by the ModelFactory and added to Set, defaults to 1.
• target: [Class] The target Blueprint Class used to create Models
• targetSet: [Class] The Set created, defaults to HashSet
• ignoreEmpty: [boolean] If true, do not create Models for an empty Set. Defaults to true.
• force: [boolean] Force the value of the MappedSet to always be set, even if the target field already has a value. Default is false.

@Nullable: Specifies this field can be null and not to set a value by the ModelFactory.

Callbacks

Callback fields can be used to inject values at the various stages of the model creation lifecycle:

ConstructorCallback: Use when constructing a new instance of the model, the model return by the callback is used by the ModelFactory. (example blueprint).

FieldCallback: Injects the return of the callback for the annotated field value (example blueprint).

AfterCreateCallback: Executed after the model has been constructed and all the fields are set (example blueprint).

Inheritance

A Blueprint will inherit the fields of its parent, except for ConstructorCallback.

Model

Presently only supports template for JavaBean Models. For annotations to work with the template, the model must follow the JavaBean getter and setters for fields.

Working with primitives

Primitive fields are intialized as zero and will never be null. This will cause the ModelFactory to think that a value has already been assigned to the model and not assign one from the blueprint. To work around this, use the force=true in the blueprint to force that value is always assigned from the blueprint, for example:

@Blueprint(Car.class)
public class CarBlueprint {
    
@Default(force=true)
float mileage = 100.1f;

ModelFactory

Creates new instances of Models based on registered Blueprints. It is possible to register Blueprints by package.

A new instance is always constructed, unless specified by a Policy.

Example of creating a new ModelFactory and registering the CarBlueprint

ModelFactory modelFactory = new ModelFactory();
modelFactory.registerBlueprint( CarBlueprint.class );

A Model with a registered Blueprint can then be created by Class:

modelFactory.createModel(Car.class);

or by passing a Model directly with override values:

Car car = new Car();
car.setMake( "Truck" );

# create a new Model using blueprint defaults, but overriding the Make to be Truck.
car = modelFactory.createModel(car); 

A Simple Example

Creating a model

ModelFactory modelFactory = new ModelFactory();
modelFactory.registerBlueprint( CarBlueprint.class );
Car car = modelFactory.createModel(Car.class);

Creating a model overriding defaults

Car car = new Car()
car.setMake( "Caddie" );
car = modelFactory.createModel(car);

Car model's Blueprint

@Blueprint(Car.class)
public class CarBlueprint {
    
    @Default
    String make = "car make";
        
    @Default
    String manufacturer = "car manufacturer";
        
    @Default
    Integer mileage = 100;
        
    @Default
    Map status = new HashMap();
}

The Car Model

public class Car {
    private String make;
    private String manufacturer;
    private Integer mileage;
    private Map status;

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public String getManufacturer() {
        return manufacturer;
    }

    public void setManufacturer(String manufacturer) {
        this.manufacturer = manufacturer;
    }

    public Integer getMileage() {
        return mileage;
    }

    public void setMileage(Integer mileage) {
        this.milage = mileage;
    }

    public Map getStatus() {
        return status;
    }

    public void setStatus(Map status) {
        this.status = status;
    }
}

Wiki of examples that includes Callbacks, Policies, and Package scanning for Blueprints.

Spring Support

There is an optional jar that provides additional support for Spring:

<dependency>
  <groupId>com.tobedevoured.modelcitizen</groupId>
  <artifactId>spring</artifactId>
  <version>0.8.1</version>
</dependency>

Avoiding Spring jar collisions

ModelFactory should work with Spring 3.x, so you can easily exclude ModelFactory's Spring depedency and use the existing one in your pom.

<dependency>
  <groupId>com.tobedevoured.modelcitizen</groupId>
  <artifactId>spring</artifactId>
  <version>0.8.1</version>
  <exclusions>
    <exclusion>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
    </exclusion>
  </exclusions>
</dependency>

What does this give me?

This provides a new class ModelFactoryBean and annotation @SpringBlueprint. When the ModelFactoryBean is registered with Spring, it allows the @SpringBlueprint and models created by the ModelFactoryBean to be injected by Spring.

Example ModelFactoryBean

<bean id="modelFactory" class="com.tobedevoured.modelcitizen.spring.ModelFactoryBean" >
    <property name="registerBlueprintsByPackage" value="com.tobedevoured.modelcitizen" />
</bean>

Example @SpringBlueprint with Spring support

@Blueprint(SportsCar.class)
@SpringBlueprint
public class SportsCarBlueprint {

    @Autowired
    SportsCarRepository sportsCarRepository;
    
    @Default
    Integer topSpeed = 100;
}

License

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.