Re: [Quickfix-developers] Re: empty tag

[Joerg T. <Joe...@ma...>]

Steve Bate wrote:
> I vote this approach as the default behavior, possibly with a
> configuration option for the other behaviors.

So do I. NoTagValue exception is the best way to handle. An optional parameter to the 
set() method sounds like a good idea.

Cheers, Jörg

>>-----Original Message-----
>>From: qui...@li... [mailto:quickfix-
>>dev...@li...] On Behalf Of Brian Erst
>>Sent: Tuesday, July 05, 2005 9:46 AM
>>To: Oren Miller; Alvin Wang
>>Cc: qui...@li...; quickfix-developers-
>>ad...@li...
>>Subject: Re: [Quickfix-developers] Re: empty tag
>>
>>QuickFIX Documentation:
>>http://www.quickfixengine.org/quickfix/doc/html/index.html
>>QuickFIX FAQ: http://www.quickfixengine.org/wikifix/index.php?QuickFixFAQ
>>QuickFIX Support: http://www.quickfixengine.org/services.html
>>
>>Oren -
>>
>>I'd definitely go with the NoTagValue exception method rather than
>>attempting to guess what the developer "really" wants.
>>
>>You have the removeField method for the case of needing to strip a
>>field out of a message, so providing a backdoor way of doing that via
>>adding a "blank" value is redundant. It also isn't obvious that "blank"
>>= "delete".
>>
>>Considering how many FIX engines choke on a missing tag value, I think
>>it's a good idea to default to not allowing it. I'd rather add a new
>>method (addBlankField or some such) or optional parameter (e.g.,
>>message.set(value, allowBlanks)) on the off chance that some weird FIX
>>implementation out there requires the existence of a tag even if there
>>is no value for it than allow what is normally considered "bad" FIX to
>>go out by default.
>>
>>- Brian Erst
>>Thynk Software, Inc.
>>
>>--- Oren Miller <or...@qu...> wrote:
>>
>>
>>>My concern is how to handle the situation where the field already
>>>exists.  If field 58 is set in the message, and I set it again with a
>>>field that has an empty tag, what does this mean?  Does it mean that
>>>I ignore the new field and retain the old value?  Or do I remove the
>>>old field from the message completely.  In which case setting a field
>>>with an empty tag is the same behavior as calling removeField.  Both
>>>of these behaviors feel a little surprising to me.  I'd be interested
>>>in hearing other opinions on this.
>>>
>>>--oren
>>>  ----- Original Message -----
>>>  From: Alvin Wang
>>>  To: Oren Miller
>>>  Cc: qui...@li... ;
>>>qui...@li...
>>>  Sent: Tuesday, July 05, 2005 9:40 PM
>>>  Subject: [Quickfix-developers] Re: empty tag
>>>
>>>
>>>
>>>  Oren, I can understand where you are coming from. It makes total
>>>sense if QF throws NoTagValue exception in this case. However, I just
>>>feel it will add workload to the developers and the production may
>>>become disruptive.
>>>
>>>  Thanks
>>>  Alvin
>>>
>>>
>>>
>>>
>>>       "Oren Miller" <or...@qu...>
>>>        07/05/2005 10:00 AM
>>>
>>>
>>>                To:
>>><qui...@li...>,
>>><qui...@li...>, "Alvin Wang"
>>><AW...@FF...>
>>>                cc:
>>>                bcc:
>>>                Subject:        Re: empty tag
>>>
>>>
>>>
>>>  We could, although more likely I would throw a NoTagValue
>>>exception.  I don't much like the idea of having QF silently ignoring
>>>a field that the developer would be expecting to go out in the
>>>message (much like I don't like the current behavior).  I can imagine
>>>the head scratching that would go on if they added a field and then
>>>found it mysteriously absent in the logs.
>>>
>>>  In either case if you have a field that might contain a blank
>>>value, I would suggest checking it before adding it to a message.
>>>
>>>  --oren
>>>  ----- Original Message -----
>>>  From: Alvin Wang
>>>  To: qui...@li... ;
>>>qui...@li...
>>>  Cc: Oren Miller
>>>  Sent: Tuesday, July 05, 2005 9:10 PM
>>>  Subject: empty tag
>>>
>>>
>>>  HI
>>>
>>>  If I set a tag as below:
>>>  message.set(new Text(text));
>>>  and if the variable "text" is null. QF will include an empty tag
>>>58. As a result, some FIX engine (such as QF itself) on the other end
>>>will reject the message.  Can QF skip including empty tag?
>>>
>>>  Thanks
>>>  Alvin


-- 
Joerg Thoennes
                                http://macd.com
Tel.: +49 (0)241 44597-24      Macdonald Associates GmbH
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