Functions supporting Message Oriented Programming (MOP)
This is the list of functions working together to implement the message oriented model. Other than this functions, it is possible to use the VMSlot class for direct access to reflected virtual machine slots. On this regards, see the Message oriented model group.
Creates a message assertion on a certain message slot.
assert( msg, data )
| msg | The message to be asserted. |
| data | The value of the assertion. |
If there are already subscribed callbacks for this message a broadcast on them is performed now.
Sends a message to every callable item subscribed to a message.
broadcast( msg, [...] )
| msg | A message (string) to be broadcast. |
| ... | Zero or more data to be broadcaset. |
| Return | true if msg is found, false if it doesn't exist. |
Broadcast function implicitly searches for a Virtual Machine Message Slot (VMSlot) with the given msg name, and if it finds it, it emits a broadcast on that.
If the message is not found, the broadcast is silently dropped (no error is raised), but the function returns false.
As calling this function requires a scan in the virtual machine message slot table, in case of repeated operations it is preferable to explicitly search for a slot with getSlot, or to create it as an VMSlot instance. On the other hand, if the reference to a VMSlot is not needed, this function allows to broadcast on the slot without adding the overhead required by the creation of the VMSlot wrapper.
Consumes currently being broadcasted signal.
consume()
Returns the given assertion, if it exists.
getAssert( msg, [default] )
| msg | The message slot on which the assertion is to be ckeched. | ||
| default | If given, instead of raising in case the assertion is not found, return this item. | ||
| Raise |
|
Retreives a MOP Message slot.
getSlot( msg, [make] )
| msg | The message slot that must be taken or created. |
| make | If true (default) create the slot if it doesn't exist. |
| Return | The message slot coresponding with this name. |
Removes a previous assertion on a message.
retract( msg )
| msg | The message slot to be retracted. |
Registers a callback to a message slot.
subscribe( msg, handler, [prio] )
| msg | A string with the message name on which the item should be registered. |
| handler | A callable item or instance providing callback support. |
| prio | Set to true to insert this subscription in front of the subscription list. |
Unregisters a registered callback from a slot.
unsubscribe( msg, handler )
| msg | A string with the message name on which the item should be registered. | ||||
| handler | A callable item or instance providing callback support. | ||||
| Raise |
|