HW05 Composer: Pocket money

Create a Business Network Archive (BNA) with the appropriate models, transactions, and access constraints that fulfill the requirements below. The BNA must have an initial transaction (setupHomework) that sets up a ledger state, where the fulfillment of each requirement can be demonstrated (assuming that the ledger is empty before the call of the initial transaction). Transactions that would dynamically add participants or assets are not needed, unless noted explicitly under the requirements, except the initializer transaction.

Please test your solution on Composer Playground before submission.

For every Participant and Asset type, the unique identifier must be a non-optional String field with the name id. The value of the field must conform to the following format: <TYPENAME>_<COUNTER>. For example, if we have a Participant type named User, then the id of the first created user must be USER_0, the id of the second user must be USER_1, etc.

Problem statement

Implement a BNA for giving a child pocket money.

• There should be two participant types: Adult and Child.
• Each adult has a name (non-unique), a partner (Adult, optional), a single child (Child, optional), a single account (required), and a phone number (required).
• Each child has a name (non-unique), a single account (required), and a phone number (required).
• Only account owners can access the funds stored.
• Owners can
  • add money to the account.
  • withdraw money from the account.
  • transfer money to another user.
• Adults have unlimited access to the funds.
• Children cannot transfer, and can only withdraw 1 unit from the funds per month.

Additional requirements:

• The initializer transaction should set up users, their partners, and their child to have the same account.
• Every user has an account.
• Transactions that add a partner or a child to a user aren't needed.
• Negative balances are not possible, transactions that'd create such a state should be rejected.

Example scenario

Alice and Bob are partners, and Claire is their child. Alice and Bob have an initial account with 10 units. Alice puts in her salary of 3 units. Later, Bob withdraws 2 units for rent. Claire withdraws 1 unit to pay his classmate Dan to do his homework, but he'd like 2 units. Claire tries to withdraw another unit, but the withdrawal fails.

Transactions

• addMoney
• withdrawMoney
• transferMoney