Merlin

Merlin is a Android database which is primarily designed for live networking objects. It provides the live object which is directly mirror the actual state of object. As mentioned It designed for work with networking that doesn't mean can't be used for general purpose database storage. In a nutshell deal directly with live managed object and put all other component like networking, caching and API's aside.

Note this is still under development with pre-release beta.

Features

• NoSQL Database
• Live Objects
• Built in Networking
• Direct Caching
• Backed by multiple database

Installation

Add it in your root build.gradle at the end of repositories:

allprojects {
  repositories {
      ...
      maven { url 'https://jitpack.io' }
  }
}

Add the dependency in your app module:

implementation 'com.github.stacknix:merlin:beta-0.0.1'

Additionally, you can use annotation processor for code generation. If you are using kotlin use kapt. (optional)

kapt 'com.github.stacknix:merlin:beta-0.0.1'

Getting Started

Create your data models, choose your preferred language, for this example we are using Kotlin.

// annotated with Model pass any name you want, must be unique though.

@Model("product")
data class Product(var id: Long, var name: String, var price: Float) : MerlinObject()

For java users:

@Model("product")
public class Product extends MerlinObject {
    public long id;
    public String name;
    public float price;
}

Add many models as you needs in same manner. Make sure always use unique model name, else compiler will through exception. You need to perform build once you add your very first model, this will generate MerlinDatabase class which we need for initialization.

Initialize

Finally, you need to initialize database. You can simply do that once for all in you Application class.

class CartApplication : Application(){
    override fun onCreate() {
        super.onCreate()
        MerlinDatabase.init(this)
        ...
    }
}

All set!

Now you can simply use your model for database operations.

Create

Once you initialize your data class use save method to create record.

Product(1, "Apple", 3.2f).save()

Read All

Following way, you can read all the record from product model.

val result = Merlin.where(Product::class.java).find()

Observe Changes

Use listen interface for observe live objects change.

result.observe {
   Log.i("All Count", it.size.toString())
}

Observe runs on UI thread

Delete All

result.deleteAll()

Filter Result

You can apply built in query filter to fit your requirement. In following example we are filtering result where name is Apple. This also apply on listen interface, you will be only observing changes where name is Apple only.

val result = Merlin.where(Project::class.java).equal("name", "Apple").find()

result.observe {
    Log.i("Apple Count", it.size.toString())
}

OR

Merlin.where(Project::class.java).equal("name", "Apple").observe {
    Log.i("Apple Count", it.size.toString())
}

If observe directly called on query it will notify initial result as well.

More Documentation Coming Soon... :)