On 8 February 2012 07:17, Marek Majkowski <span dir="ltr"><<a href="mailto:majek04@gmail.com">majek04@gmail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Take a look at the readme:<br>
<a href="https://github.com/tonyg/presence-exchange#readme" target="_blank">https://github.com/tonyg/presence-exchange#readme</a><br>
<br>
"bindings made with the empty string "" as their binding<br>
key, which receive presence messages, but do not<br>
produce them; and bindings made with any other binding key,<br>
which produce presence messages but do not receive them."<br></blockquote><div><br>Also, remember that queues can bind to the same exchange more than once! So it's perfectly acceptable for some queue to bind twice to a presence-exchange, once with key "" (in order to *receive* presence messages) and again with key "myname" (in order to *issue* a presence message).<br>
<br>The reason it is the way it is is so that asymmetrical situations can be cooked up on demand. Binding twice is one easy way of producing a symmetrical situation.<br><br>Regards,<br> Tony<br><br>
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