Problem drawing image with java/mapscript when starting with a blank mapObj

[Umberto Nicoletti]

On 7/10/06, James Dracup <jamesdracup at hotmail.com> wrote:
> No need for a bug, I had a play over the weekend and found my error.

All's well what ends well!

>
> I am populating my mapObj from tables in a db.  If the value is not null in
> the db, I call the corresponding set method in mapscript.  In my 'style'
> table I have 'size' column which was set to have a default value of 0, and
> was never null.  I therefore always called styleObj.setSize() - usually
> passing 0.  That I think is what was messing me up - changing the default to
> null for that column fixed the issue.
>
> The reason it worked when passed through a .map file, and the reason I did
> not initially spot the mistake, was because SIZE is not set in the STYLE
> section on any of the map files - so it looked as if the mapObjs were the
> same, but in fact reloading it caused the size value to be forgotten.
>
> Umberto, thanks for the prompt response in any case and - at a guess from
> your name - congratulations on the World Cup :)
>

Thanks! We're very proud of our team even in the light of recent scandals...

Umberto

> Cheers,
> James.
>
> ----Original Message Follows----
> From: "Umberto Nicoletti" <umberto.nicoletti at gmail.com>
> To: "James Dracup" <jamesdracup at hotmail.com>
> CC: MAPSERVER-USERS at lists.umn.edu
> Subject: Re: [UMN_MAPSERVER-USERS] Problem drawing image with java/mapscript
> when starting with a blank mapObj
> Date: Sat, 8 Jul 2006 12:11:17 +0200
>
> Please open an issue on mapserver bugzilla.
> I'll look into ti asap.
>
> Umberto
>
> On 7/7/06, James Dracup <jamesdracup at hotmail.com> wrote:
> >Hello,
> >
> >I am using java/mapscript embedded inside a java program and am having a
> >few
> >problems.  I wonder if anybody has any suggestions, or if it is something
> >obvious I have missed?
> >
> >I create a new mapObj in java, but NOT from a .map file, a blank one:
> >
> >mapObj  mapobj = new mapObj(null);
> >
> >There is then a fairly long and complicated chunk of code to populate that
> >mapObj from a db and user input with settings and layers etc. etc.
> >
> >I finally do:
> >
> >byte[] bytes = mapobj.draw().getBytes();
> >
> >Intending to then further process in java the image returned.
> >
> >However, I always get a blank (just background colour) image.  Initially I
> >thought I'd missed something out when setting the parameters for the
> >various
> >mapscript objects, but, having looked at that for a while, I now do not
> >think that is the problem.
> >
> >If I do a mapobj.save("MapFileName.map") - the .map file outputted is
> >perfect, and works fine (displays a map) in all contexts (cgi-bin, java
> >mapscript).
> >
> >I can load that .map file into a new mapObj, and the image produced is
> >fine:
> >
> >mapObj  newmapobj = new mapObj("MapFileName.map");
> >byte[] bytes = newmapobj.draw().getBytes();
> >
> >If I then do a newmapobj.save("MapFileToCompare.map") - the .map file
> >outputted is absolutely and completely identical (did a diff) to the
> >original one outputted.
> >
> >So I am really confused - it seems to me the mapObj's are identical - so
> >why
> >do I need to go via the file system in order to produce an image?  What
> >changes, and how can I avoid it?
> >
> >Any thoughts,
> >Thanks,
> >James
> >
>
>
>