Re: [Quickfix-developers] catch getField business rejects

[Dale W. <wil...@oc...>]

Hi Caleb (et. al.)

Caleb Epstein wrote:

> On 11/22/05, *Reiner Nix* <rei...@ma... 
> <mailto:rei...@ma...>> wrote:
>
>     Having get and set method without throwing an exception but able
>     to manage
>     null values. So a setFieldXXX (null) should suppress submitting
>     the value in
>     the FIX message where getFieldXXX() for an unset value should
>     return null. 
>
>
> I don't think this particular interface would work in C++ (we're 
> dealing with either FIX::FieldBase or std::string objects and there is 
> no "null").  It would be possible to provide some additional 
> getField/setField overloads in FieldMap that would do what you want 
> though:
>
> namespace FIX {
>
> struct nothrow {};
>
> class FieldMap {
>    ...
>    bool getField (FieldBase& field, nothrow) // doesn't throw; returns 
> true is hasField (field)
>    bool getField (int field, std::string&) // doesn't throw, returns 
> true if hasField (field)
>
Rather than overload based on a bool (or adding a bool with a default) 
I'd much rather see:

     bool getOptionalField(FieldBase& field);

This makes it much more obvious (to me anyway) when to use this method:  
If the field is optional then it's not an exception for it to be missing.

That being said, I really like the idea, 'cause I'm certainly tired of 
typing:

   if(message.isSetField(filbert))
  {
       message.getField(filbert);
       etc
   }


> I can't really see the value in them, but these could also be added:
>
>     bool setField (const FieldBase&, nothrow) // doesn't throw (and 
> has no effect) if value is empty
>     bool setField (int field, const std::string& value, nothrow) // 
> same as above

Agreed, these don't make a whole lot of sense.

Dale

>
> If people really want these interfaces they'd be very simple to add.
>
> -- 
> Caleb Epstein
> caleb dot epstein at gmail dot com 



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  Dale Wilson, Senior Software Engineer
  Object Computing, Inc. (OCI)
  http://www.ociweb.com/  http://www.theaceorb.com/
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