Getting Started

Getting Started

After installing datum SDK, in order to start using datum SDK you will need to do the following :

1. Create Datum ID.
2. init Datum object with the ID created from step 1.
3. Get Some DAT (on test net this is done through our Faucet).
4. Deposit DAT to storage contract.
5. Setting & Retrieving data.

Installation

npm i --save datum-sdk

Creating Datum ID

const Datum = require('datum-sdk');
let password = "password";


Datum.createIdentity('Password')
.then((id)=>{
  console.log(id);
});

Output

{
   "seed": "around evidence renew filter winter race differ hammer country error arrive man",
   "keystore":"{
     "encSeed":
     {"encStr":"iJeDYSA3RYFjlz1Alini1LblZcea…cjkI3z4SM3mgbYnfhu/Qx8=",
       "hdIndex":1,
       "version":3
       }"
     }
}

• Password is used to encrypt the created keystore.
• Seed must be stored since it is used for recovery, it is up to the SDK user to choose how he will do that, or how he will instruct the DAPP user to do that.
• Notice that value of keystore is stringified.

initilize Datum Object

async function createID(password){
  let id = await Datum.createIdentity(password);
  let tmpDatumObj = new Datum();
  tmpDatumObj.initialize({
    identity:id.keystore
  });
  tmpDatObj.identity.storePassword(password);
  return tmpDatumObj;
}

• We initialize datum obj with the keystore, which only contains the encrypted keystore
• tmpDatObj.identity.storePassword allows us to do future calls without providing the password on every call

Getting DAT

You can get DAT on the test network through our Faucet.

GET https://faucet.megatron.datum.org/v1/faucet/dat/[Wallet_Address]

• Currently faucet returns 10 DAT Example

fetch(`https://faucet.megatron.datum.org/v1/faucet/dat/${datum.identity.address}`)
.then(response=>{
  return Datum.getBalance(datum.identity.address);
}).then(balance=>console.log(`Your balance: ${balance}`));

To check your Balance

Datum.getBalance(datum.identity.address).then(balance=>{console.log(balance)});

• Note it will take sometime before the balance is reflected due to mining time.
• Balances are shown in WEI, so you need to convert them to ETH

Depositing DAT to storage contract

datum.deposit(3).then(hash=>{console.log(`TX Hash: ${hash}`)});

To check your current deposited balance

datum.getDepositBalance().then(dbalance=>{console.log(dbalance)});
//Alternatively you can also use the following
Datum.getDepositBalance(datum.identity.address).then(dbalance=>{console.log(dbalance)});

• To be able to perform operations on the data (SET/GET/DELETE...) you need to first prepay or top up your balance in the storage contract first.

• After depositing/Prepaying DAT to storage contract, your balance will be deducted based on what operation you are performing on the data.

• You have the option to withdraw the unused amount of DAT that you deposited. To withdraw 1 DAT from deposited balance

datum.withdrawal(1)
.then(response=>{
  console.log(response);
  return Datum.getBalance(datum.identity.address;
  }))
.then(balance=>console.log(`Your current balance: ${balance}`));

Setting & Retrieving data

After we perform the previous operations, now we can use datum storage nodes to persist data

datum.set({msg:'hello world :)'})
.then(itemHash=>{
  //itemHash= 0xcd06fc30e91efdeef6adf4e8925f2d753521975cac268c426316570c15df53be
  return datum.get(itemHash);
})
.then(data=>{
  console.log(data); //output: "{"msg":"hello world :)"}"
})