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Re: white spaces before keywords



Hi Kevin,

MessSend (from the xAP labs package) default messages contain those
initial spaces. This made me doubt.

Thanks for the confirmation.

Daniel.


--- In xAP_developer@xxxxxxx, Kevin Hawkins <lists@...> wrote:
>
> Hi Daniel,
>
>     Not quite sure where you're seeing the white space in the example
> message.  In the documentation for xAP we often indent the
parameters to
> make the readability of the content better, however this is not what
is
> sent 'on the wire' .  The xFX apps like Viewer will strip this.  There
> should be no white space between the end of one line <LF> and
the first
> character of the next parameter name,  or from the end of that name to
> the = sign.  Embedded space within a parameter name is permissible
> though and both leading, trailing and embedded white space is
allowable
> in parameter values.  From the spec....
>
>    Each message block is defined by a keyword line.
>
> This keyword uses alpha-numeric printable characters a..z (a through
z)
> 0-9 (zero through nine), _ (underscore), - (minus) and, additionally,
> embedded _ (space).
>
> Leading and trailing white space (_ - character space, ASCII character
> 32 decimal) is not permitted. Message block names may include embedded
> spaces.
>
> <snip>
>
> Each name-value pair within the message block is defined by a
keyword, a
> delimiter, a value and a terminator.
>
>     * The keyword follows the same construct as that described above
for
>       a message section keyword definition.
>
> <snip>
>
> (For parameter values)
>
>     The default behaviour is for leading and trailing white space to
be
> treated as significant in the value field. All white space between
the =
> and terminating <LF> character is considered significant. This
allows
> for the inclusion of leading white space and trailing white space in
> string literal values.
>
>
>     Kevin
>
> estratosapiens wrote:
> >
> > I've seen that some xAP applications send messages with white
spaces
> > before the keywords. For instance:
> >
> > xap-header
> > {
> > v=12
> > hop=1
> > uid=FF456700
> > class=xAPBSC.query
> > source=...
> > }
> > ...
> >
> > xAP HUB GUI reads correctly these messages, so, I wonder if I
> > misunderstand the protocol definition when it says "...white
space
> > which would not normally be present in the message when
transmitted on
> > the wire..."
> >
> > Should I develop my xAP interface to eliminate white spaces
before
> > keywords?
> >
> > Thanks for your help,
> >
> > Daniel.
> >
> >
>












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