Database

Nano framework has inbuilt database module that uses realm.

Storing and reading data from default table:

All the methods like onPress, onLongPress, onStart, onResume, onPause and onEnd in framework has access to moduleParams parameter that has all the available modules, you can use database module from it like below.

By default Nano framework creates a table called key-value in realm database. It helps you store key-value data quickly right away.

For example, below is the code to store/update key-value data using setValue method from database module.

const buttonPress = {
  component: NANO.BUTTON,
  value: 'CLICK TO SAVE DATA TO SESSION',
  onPress: ({ moduleParams }) => {
        moduleParams["database"].setValue("name", "value") 
  }
};

const screen = {
  name: 'HomeScreen',
  screen: {
    h1: [buttonPress],
  }
};

You can read and delete data from database in any screen using getValue, deleteValue and deleteAllValues like below.

const text2 = {
  component: NANO.TEXT,
  value: "I AM IN ANOTHER SCREEN",
};

const screen = {
  name: 'AnotherScreen',
  screen: {
    h1: [text],
  },
  onStart: ({moduleParams}) => {
      
      // read single value
      console.log(moduleParams["database"].getValue("name"))

      // delete single value
      moduleParams["database"].deleteValue("name")


      // delete All values
      moduleParams["database"].deleteAllValues()
      
    
  }
};

Creating new table, storing, reading data from it:

For creating a new table, you can create it's schema in nano.config.js file like below and increasing its version to higher number other than 1.

below is the simple table named books.

nano.config.js

const books = { 
   name: "books",
   properties: {
    _id: 'string',
    name: 'string',
    author: 'string',
   },
   primaryKey: '_id', 
}

export const DataBaseConfig = {
  schema: [books]
  schemaVersion: 2,
  encryptionKey: new Int8Array(64) // You can encrypt the realm database file on disk with AES-256 + SHA-2 by supplying a 64-byte encryption key when opening a realm.
}; 

Here is how you can store/update and data from books table using setData, updateData, deleteData, deleteAllData and deleteAll.

const buttonPress = {
  component: NANO.BUTTON,
  value: 'CLICK TO SAVE DATA TO DATABASE',
  onPress: ({ moduleParams }) => {

        // adding new data into books table
        moduleParams["database"].setData("books", {
          "_id" : "1",
          "name" : "Nice book by Nano",
          "author" : "Mr. Author"
        }) 

        // You can update with passing primary key as second parameter
        moduleParams["database"].updateData("books","_id","1", {
          "_id" : "2",
          "name" : "Updated Nice book by Nano", 
          "author" : "Updated Mr. Author"
        }) 

        // You can delete with passing primary key/coloumn name and its value
        moduleParams["database"].deleteData("books","_id", "2") 

        // You can delete all data of a table
        moduleParams["database"].deleteAllData("books") 

        // You can delete all data from all tables
        moduleParams["database"].deleteAllTables() 
        

  }
};

const screen = {
  name: 'HomeScreen',
  screen: {
    h1: [buttonPress],
  }
};

Here is how you can read data from books table using getDataByPrimaryKey and getData.

const text2 = {
  component: NANO.TEXT,
  value: "I AM IN ANOTHER SCREEN",
};

const screen = {
  name: 'AnotherScreen',
  screen: {
    h1: [text],
  },
  onStart: ({moduleParams}) => {
      
      // read single row
      console.log(moduleParams["database"].getDataByPrimaryKey("books", "2"))
    
      // read all data 
      console.log(moduleParams["database"].getData("books"))
    
  }
};

If you want more access to created realm database, you can always use getRealmInstance method to get the relam instance and use according to your needs.

const buttonPress = {
  component: NANO.BUTTON,
  value: 'CLICK TO GET INSTANCE',
  onPress: ({ moduleParams }) => {

        // get entire realm Instance
       const realmInstance =  moduleParams["database"].getRealmInstance()

  }
};

const screen = {
  name: 'HomeScreen',
  screen: {
    h1: [buttonPress],
  }
};