JavaScript smart contracts

Bloqly engine is responsible for validating and storing states of documents. Each document state change is represented by new value property of a transaction.

It is possible that a bad client can create a transaction which doesn't respect the typical state diagram of a document.

For example, let's imagine there is a document, representing a child enrollment form in a school. It can be in statuses 'RECEIVED', 'IN_PROGRESS', 'CONFIRMED', 'REJECTED'.

Without blockchain validating these statuses, it is possible to create 'CONFIRMED' status right away.

In order to address this issue, Bloqly introduces state-free functional smart contracts which can be written in JavaScript and other scripting languages (Python, Ruby etc).

Smart contract code representing the provided example:

const STATUSES = ['RECEIVED', 'IN_PROGRESS', 'CONFIRMED', 'REJECTED'];

const INITIAL_STATUS = 'RECEIVED';

const STATUSES_CHANGE = {
    'RECEIVED': ['IN_PROGRESS', 'RECEIVED'],
    'IN_PROGRESS': ['CONFIRMED', 'REJECTED'],
    'CONFIRMED': [],
    'REJECTED': [],
};

function confirm(value, prev, space, key) {

    const prevValue = prev || INITIAL_STATUS;

    const statusExists = STATUSES.indexOf(value) !== -1;

    const nextStatusAllowed = STATUSES_CHANGE[prevValue].indexOf(value) !== -1;

    return statusExists && nextStatusAllowed;
}

Method confirm is called each time new transaction received. In the case it returns false, no data will be stored in blockchain.