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Re: xAP EOM identifier in xAP v1.3



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The original xap spec provides extensions for framing a message over async
serial which also delimit the start of the message - you don't need this
'hack' if you follow the original spec for non-UDP transports.

Patrick

2009/9/13 Kevin Hawkins <yahoogroupskh@xxxxxxx>

>   We have been asked on several occasions how to detect the end of a
> xAP messager as there is no unique EOM character.  Typically in any
> reasonable sized packet structured transport eg UDP then the packet
> provides such an indication but on systems with small packets or non
eg
> asynchronous serial this is not useable.
>
>   In discussing this with the specification team we must consider
> backwards compatability and so we do not wish to alter the
specification
> to include a unique EOM character.  What we do propose however is that
> xAP v1.3 will specify that all messages should end with two
consecutive
> chr(10)'s immediately after the closing '}'
>
> ie  ..... 7D 0A 0A
>
>  Some apps, even v1.2 ones,  already do this.  We don't believe this
> will cause any backwards compatibility issues and it will always be
> unique within a xAP message.
>
>  So, in developing xAP v1.3 apps could you therefore append  two 0A's
> at the end of your messages , and of course handle incoming messages
> containing such.
>
>   K
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>

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The original xap spec provides extensions for framing a message over async
=
serial which also delimit the start of the message - you don&#39;t need
thi=
s &#39;hack&#39; if you follow the original spec for non-UDP
transports.<br=
>
<br>Patrick<br><br><div
class=3D"gmail_quote">2009/9/13 Kevin Hawkins <span=
dir=3D"ltr">&lt;<a href=3D"mailto:yahoogroupskh@xxxxxxx";>yahoogroup=
skh@xxxxxxx</a>&gt;</span><br><blockquote
class=3D"gmail_quote" styl=
e=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt
0.8ex; =
padding-left: 1ex;">
=A0 We have been asked on several occasions how to detect the end of
a<br>
xAP messager as there is no unique EOM character. =A0Typically in
any<br>
reasonable sized packet structured transport eg UDP then the
packet<br>
provides such an indication but on systems with small packets or non
eg<br>
asynchronous serial this is not useable.<br>
<br>
=A0 In discussing this with the specification team we must
consider<br>
backwards compatability and so we do not wish to alter the
specification<br=
>
to include a unique EOM character. =A0What we do propose however is
that<br=
>
xAP v1.3 will specify that all messages should end with two
consecutive<br>
chr(10)&#39;s immediately after the closing
&#39;}&#39;<br>
<br>
ie =A0..... 7D 0A 0A<br>
<br>
=A0Some apps, even v1.2 ones, =A0already do this. =A0We don&#39;t
believe =
this<br>
will cause any backwards compatibility issues and it will always
be<br>
unique within a xAP message.<br>
<br>
=A0So, in developing xAP v1.3 apps could you therefore append =A0two
0A&#3=
9;s<br>
at the end of your messages , and of course handle incoming
messages<br>
containing such.<br>
<br>
=A0 K<br>
<br>
<br>
------------------------------------<br>
<br>

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