org.nodal.model
Interface TxnBuilder

All Superinterfaces:

Txn

All Known Implementing Classes:

memTxn

public interface TxnBuilder

extends Txn

Interface for incrementally building Txns. Created on Sep 8, 2003

Author:

leei

Method Summary

TxnOp	addOp(Node subj, Operator op) Create a TxnOp and add it to the list of TxnOps in this Txn.
boolean	commit() Commit the currently accumulated Txn.
boolean	retractOp(TxnOp op) Retract a TxnOp from this Txn.

Methods inherited from interface org.nodal.model.Txn

attribution, committed, inverse, ops, repository, resolved, subjectList, subjects

Method Detail

addOp

public TxnOp addOp(Node subj,
                   Operator op)

Create a TxnOp and add it to the list of TxnOps in this Txn.

Parameters:

subj - the Node that is operated on by this TxnOp

op - the Operator that modifies/creates the subj Node

Returns:

a new TxnOp that records this Operator

retractOp

public boolean retractOp(TxnOp op)

Retract a TxnOp from this Txn. Fails if the TxnOp was not produced by and addOp on this TxnBuilder.

Parameters:

op - the TxnOp to be retracted

Returns:

true if successful

commit

public boolean commit()

Commit the currently accumulated Txn.

Returns:

true if we are successfully able to commit.