I believe the spec is describing about the pubsub mechanism with container act as bridge between gadgets such that they dont have to now about each other existance.
- Henry On Thu, Dec 29, 2011 at 1:57 AM, Wei CSDL Shi <shiwc...@cn.ibm.com> wrote: > The gadget topics are coded in the gadget xml, developers call the > gadgets.Hub.publish or subscribe function directly. It seems that such > gadget to gadget communication is defined by gadget developer. The use case > I am trying to have is that the end user or the container of the gadgets, > can somehow have the ability to connect the gadget instances through topics. > > Quote from > http://opensocial-resources.googlecode.com/svn/spec/2.0.1/Core-Gadget.xml, > C.12.6 Wiring Metadata: > > The OpenSocial specification defines additional metadata that can be used > to describe the events that a gadget publishes or to which it is able to > subscribe. This allows the container to automatically "wire" gadgets > together, and/or provide a UI that allows the user to wire publisher > gadgets to subscriber gadgets. For example, manual wiring is often > necessary because there sometimes are multiple widgets publishing to or > subscribing to the same topic, such as "date", where one widget might > provide a start date and the other widget an end date, and also because > sometimes topic names and/or payload types are too generic for automatic > mapping. > > I searched in the common container source code, but I didn't find any > related implementation to support end user to wire gadget instances. If > pub-sub feature is not the one that I should leverage to implement such use > case, do you have any other recommendation? > > Thanks > Best Regards > > Marshall Shi(Shi Wei) > > [image: Inactive hide details for Craig McClanahan ---2011-12-29 > 16:50:17---On Thu, Dec 29, 2011 at 12:23 AM, Wei CSDL Shi <shiwcsdl@cn]Craig > McClanahan ---2011-12-29 16:50:17---On Thu, Dec 29, 2011 at 12:23 AM, Wei > CSDL Shi <shiwc...@cn.ibm.com> wrote: > > > *Craig McClanahan <craig...@gmail.com>* > > 2011-12-29 16:46 > Please respond to > dev@shindig.apache.org > > > > To > > dev@shindig.apache.org > cc > > > Subject > > Re: dynamic wire for gadgets > On Thu, Dec 29, 2011 at 12:23 AM, Wei CSDL Shi <shiwc...@cn.ibm.com> > wrote: > > > Yes, I am looking for how to setup wire between specific gadget > instances. > > I've checked the gadget topics, it seems that once gadget A published a > > topic, all the gadget B instances which subscribed to that topic, will be > > invoked. Is there a way that I can only invoke one specific gadget B > > instance when I publish a topic? > > > That desire seems totally opposite of the whole reason that pub-sub > architectures exist in the first place. The basic idea is that gadget A > says "here is something that happened" with absolutely no knowledge about > who might or might not be listening. The fundamental principle is to > separate the event producers and the event listeners, after all. > > If you care about a particular B being the only one receiving that > notification, why not set up a private topic that only that particular B > instance listens to? Or use some completely separate 1:1 mechanism, since > pub-sub is obviously not what you really want? > > Craig McClanahan > >
