Refactored Document properties related to transactions

Two existing properties have been re-implemented to better complement the changes in the transaction framework:

• Document.IsReadOnly

Indicates that a document is – either temporarily or permanently – in read-only state. If it is read-only, it would mean that new transactions may not be started in that document, thus no modification could be made to the model.

• Document.IsModifiable

Indicates whether a document is or is not currently modifiable. A document is not modifiable if either there is no transaction currently open or when some temporary state lock modification for a certain operation. Taken from another perspective, a transaction may be started only when document is not yet modifiable, but is also not read-only.

Transactions in events

All events have been changed to no longer automatically open transactions like they originally did in earlier releases. As a result of this new policy, the document will not be modified during an event unless one of the event’s handlers modifies it by making changes inside a transaction. A transaction may be opened by either the event handler if there is no transaction already opened (sometimes when the event is invoked, there is already a trasnaction open). If an event handler opens a transaction it is required that it will also close it (commit it or roll it back), otherwise all eventual changes will be discarded.

Please be aware that modifying the active document is not permitted during some events (e.g. the DocumentClosing event). If an event handler attempts to make modifications during such an event, an exception will be thrown. The event documentation indicates whether or not the event is read-only.