java-redux

JavaRedux is an implementation of Redux library in Java

Quick Start

Prerequisites

A working Java app with maven or gradle set up
Learn more about Maven or Gradle

Usage

Installation with Maven

1. Add this to pom.xml file

   <dependency>
     <groupId>com.rupindr</groupId>
     <artifactId>java-redux</artifactId>
     <version>1.0</version>
   </dependency> 
   

2. Run via command line

   mvn install 
   

Installation with Gradle

1. Add following to build.gradle

   implementation "com.rupindr:java-redux:1.0"
   

2. Run ./gradlew build via command line

Basic code example

Here is a basic usage example. Each component is explained in detail, further down in this guide.

Create a class representing the state of the application

class AppState implements State {           // each state class must implement State interface

    public String property1 = "";           // we can make these private...
    public String property2 = "";           // ... and provide getters and setters

    @Override
    public int compareTo(Object o) {        // state class must implement compareTo method
        AppState appState = (AppState) o;
        return (this.property1.equals(appState.property1) && this.property2.equals(appState.property2)) ? 0 : 1;
    }
    
    /* clone method */
}

Create a store

Store<AppState> store = new Store<>(); //       store is a state container

Register one or more reducers. Reducer modifies the state based on Actions

store.registerReducer("main", (action, state) -> {              // Here "main" is the name of the reducer
    AppState newState = state.clone();                          // It is recommended to create new state object
    switch (action.getType()) {
        case "SET_PROP1":                                       // Multiple case blocks modify state according to Action type
            newState.property1 = (String) action.getPayload();  // Never update state properties directly except from within a reducer function
            return newState;
        
        case "SET_PROP2":
            newState.property2 = (String) action.getPayload();
            return newState;
    }
    return state;
}, new AppState());                                             // Third optional parameter is initial state. It is null by default.

Subscribe with one or more event handlers on the reducer. All handlers will be called every time the state changes for that specific reducer.

store.subscribe("main", state -> System.out.println("This is first handler. Property 1 value is " + state.property1));
store.subscribe("main", state -> System.out.println("This is second handler. Property 2 value is " + state.property2));

Execute (Dispatch) the actions. There are multiple ways to do this.

store.dispatch(ActionCreator.create("SET_PROP1", "New value"));
store.dispatch(new Action<String>("SET_PROP2", "New value for prop 2"));

Get the state using store.getState(), It returns a map {reducerName -> stateObject}

License

Copyright 2021 Rupinder Singh

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.