Re: white spaces before keywords

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

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.
>
>