This is really cool, and exactly what I need. I will get some time later to implement this and try it out, and I am sure I'll have more questions and comments. Thanks again for this. Gloria > On Mar 2, 8:36 pm, Gloria W <strang...@comcast.net> wrote: > >> Matt, thanks for this response. It took me a while to get through it and >> make sure I understood each point. I appreciate it, comments are below. >> > > No problem. > > I've just realised another way to achieve the same effect that is > probably simpler! > > There *is* a component that is all about getting things done in an > order: the Seq component (The name is a homage to the OCCAM language): > > http://www.kamaelia.org/Components/pydoc/Kamaelia.Chassis.Seq.html > > With Seq, you provide a list of components. Seq goes through the list, > starting with the first component. It activates it and wires up its > inboxes and outboxes so that they're mapped to the Seq component's > inboxes and outboxes (just like the Carousel does). When that > component finishes, it then unwires it and moves onto the next in the > list. It therefore effectively runs them *in sequence* one after the > other. > > We've got two steps: displaying the initial message, then taking user > input. Both steps need their output to be displayed. So we'll create a > Seq componet, Pipeline'd into a console echoer: > > from Kamaelia.Chassis.Seq import Seq > > Pipeline( > Seq( ... args to be determined! ... ), > ConsoleEchoer() > ).run() > > We can use a OneShot component (see > http://www.kamaelia.org/Components/pydoc/Kamaelia.Util.OneShot.html > ) to send that initial message, so that it gets sent to the > ConsoleEchoer and displayed. OneShot, rather conveniently, then > immediately terminates; so the Seq component will move onto the next > component in its list. That next component can be the Pipeline of a > ConsoleReader, sending its output into MyComponent. > > So what we have is: > > from Kamaelia.Chassis.Seq import Seq > from Kamaelia.Util.OneShot import OneShot > > Pipeline( > Seq( > OneShot("initial message to be displayed"), > Pipeline( > ConsoleReader(), > MyComponent() > ) > ), > ConsoleEchoer() > ).run() > > In this case, MyComponent doesn't need to bother to send the initial > message itself, as it did in the suggestion I previously made. > > So what happens here? Well, when the system starts running, initially > the Seq component selects the first item in its list - the OneShot > component. So, what actually ends up getting wired up is something > like this: > > Pipeline( > OneShot("initial message to be displayed"), > ConsoleEchoer() > ) > > Its not actually exactly like that, because the OneShot is still > contained within the Seq component - but because all the inboxes and > outboxes are mapped to that of the Seq component, it is roughly > equivalent. > > Then when the OneShot component has sent its message and terminated, > the Seq component swaps it out and replaces it with the next thing in > its list - the pipeline of a ConsoleReader and MyComponent. So the way > the system is wired up suddenly switches to something akin to this: > > Pipeline( > Pipeline( > ConsoleReader(), > MyComponent() > ), > ConsoleEchoer() > ) > > Again, the inner pipeline is, in reality, contained within the Seq > component, but it behaves roughly like it is shown. > > > > > Matt > > > > > > >
--~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "kamaelia" group. To post to this group, send email to kamaelia@googlegroups.com To unsubscribe from this group, send email to kamaelia+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/kamaelia?hl=en -~----------~----~----~----~------~----~------~--~---
