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migrate

Contract: JBPayoutRedemptionPaymentTerminal​‌

Interface: IJBPayoutRedemptionPaymentTerminal

Allows a project owner to migrate its funds and operations to a new terminal that accepts the same token type.

Only a project's owner or a designated operator can migrate it.

Definition​

function migrate(uint256 _projectId, IJBPaymentTerminal _to)
  external
  virtual
  override
  requirePermission(projects.ownerOf(_projectId), _projectId, JBOperations.MIGRATE_TERMINAL)
  returns (uint256 balance) { ... }
  • Arguments:
    • _projectId is the ID of the project being migrated.
    • _to is the terminal contract that will gain the project's funds.
  • Through the requirePermission modifier, the function is only accessible by the project's owner, or from an operator that has been given the JBOperations.MIGRATE_TERMINAL permission by the project owner for the provided _projectId.
  • The function can be overriden by inheriting contracts.
  • The resulting function overrides a function definition from the IJBPayoutRedemptionPaymentTerminal interface.
  • The function returns the amount of funds that were migrated, as a fixed point number with the same amount of decimals as this terminal.

Body​

  1. Make sure the token type of the terminal being migrated to matches the token type of this terminal.

    // The terminal being migrated to must accept the same token as this terminal.
    if (!_to.acceptsToken(token, _projectId)) revert TERMINAL_TOKENS_INCOMPATIBLE();

    Internal references:

    External references:

  2. Record the migration and get a reference to the project's balance.

    // Record the migration in the store.
    balance = store.recordMigration(_projectId);

    Internal references:

    External references:

  3. If there's a balance to migrate, move the funds over to the new terminal. Send ETH along with the transaction if this terminal is an ETH terminal. Make sure any inherited pre-transfer logic is called before transferring.

    // Transfer the balance if needed.
    if (balance > 0) {
      // Trigger any inherited pre-transfer logic.
      _beforeTransferTo(address(_to), balance);

      // If this terminal's token is ETH, send it in msg.value.
      uint256 _payableValue = token == JBTokens.ETH ? balance : 0;

      // Withdraw the balance to transfer to the new terminal;
      _to.addToBalanceOf{value: _payableValue}(balance, _projectId, token, '', bytes(''));
    }

    Library references:

    Virtual references:

    Internal references:

  4. Emit a Migrate event with the relevant parameters.

    emit Migrate(_projectId, _to, balance, msg.sender);

    Event references: