layer->queryByFeatures strangeness

[Tim Norris]

Hi all

I have discovered a strange difference between mapServer 4.4.2 and mapServer
4.6.0. - particularly with the $layer->queryByFeatures() method under
PHP/Mapscript.

Currently I have two machines configured as below

Machine #1
Fedora Core 3
PHP 5.0.3 :: './configure' '--enable-shared' '--with-regex=system'
'--with-jpeg-dir=/usr' '--with-png-dir=/usr' '--with-zlib'
'--with-gd=/usr/local' '--with-freetype-dir=/usr'
'--enable-force-cgi-redirect' '--enable-dbase' '--with-pdflib'
'--with-mysql' '--with-config-file-path=/usr/local/php/'
'--prefix=/usr/local/php'
MapServer version 4.4.2 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT
SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT INPUT=EPPL7 INPUT=OGR INPUT=GDAL
INPUT=SHAPEFILE

Machine #2
Fedora Core 4
PHP 5.0.3 :: './configure' '--enable-shared' '--with-regex-system'
'--with-png-dir=/usr' '--with-zlib' '--with-gd=/usr/local'
'--with-freetype-dir=/usr' '--enable-force-cgi-redirect' '--enable-dbase'
'--with-pdflib' '--with-mysql' '--with-config-file-path=/usr/local/php/'
'--prefix=/usr/local/php'
MapServer version 4.6.0 OUTPUT=GIF OUTPUT=PNG OUTPUT=WBMP OUTPUT=SVG
SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT
SUPPORTS=WFS_SERVER SUPPORTS=THREADS INPUT=EPPL7 INPUT=OGR INPUT=GDAL
INPUT=SHAPEFILE

There is no relevant part of the map file - both layers that are relevant
are dynamically loaded depending on the request.

The relevant script is as follows (PHP):

// this is a dynamically loaded point layer - MapInfo format
$lyr_currentLink = ms_newLayerObj($ms_map);
$lyr_currentLink->set('name',$my_link_name);
$lyr_currentLink->set('type',MS_LAYER_POINT);
$lyr_currentLink->set('status',MS_ON);
$lyr_currentLink->set('connection',"myLocationData.TAB");
$lyr_currentLink->set('connectiontype',MS_OGR);
$lyr_currentLink->setProjection("proj=latlong");
$obj_linkClass = ms_newClassObj($lyr_currentLink);
$obj_linkClass->set('template','NULL');
// there is more script defining colors etc. . . .

// this is a dynamically loaded polygon district layer - MapInfo format
$lyr_districts = ms_newLayerObj($ms_map);
$lyr_districts->set('name',$my_districts);
$lyr_districts->set('type',MS_LAYER_POLYGON);
$lyr_districts->set('connection',"myDistricts.TAB");
$lyr_districts->set('connectiontype',MS_OGR);
$lyr_districts->setProjection("proj=latlong");
$obj_districtsClass = ms_newClassObj($lyr_districts);
$obj_districtsClass->set('template','NULL');
// more script defining colors etc. . . .

// get the correct district based on the request - querying against the
field "DN" with the $my_district_number from the request.
$b_qRes=$lyr_districts->queryByAttributes("DN",$my_district_number,"MS_SINGLE");
$obj_district = $lyr_districts->getResult(0);
// NOTE: I open the layer and get the feature for drawing later - perhaps
this is part of the problem and there is a better way to draw the particular
district? using the layer->drawQuery() method? would this make a difference?
$lyr_districts->open();
$ftr_district=$lyr_districts->getShape($obj_district->tileindex,$obj_district->shapeindex);
// then I create a new layer and add the $ftr_district to the new layer with
all of its colors etc. . . .

// now for the problem query - specificially to count the point data within
the district
$lyr_currentLink->queryByFeatures($lyr_districts->index);
$str_locationCount = $lyr_currentLink->getNumResults();

now for the wierdness: on both machines the code executes without error, BUT
on the 4.4.2 version I get the correct number and on the 4.6.0 version I get
an incorrect count (it is way to high).

As an aside - I have tried using the $layer->queryByShape($ftr_district)
method and keep getting errors (either mapServer crashes entirely with no
visible error message in 4.4.2 or, once again the wrong count in 4.6.0 -
incidentally it is the SAME wrong count) - this includes the reprojection of
the $ftr_district->project($inProj,$outProj) to make sure that there are no
projection problems/conflicts.

any help on this would be great - I would like to use the 4.6.0 version, but
right now I cannot get it to return the correct result - perhaps a bug??? or
perhaps I am doing something wrong???

and another aside - which documentation set is current????
http://ms.gis.umn.edu/ OR http://mapserver.gis.umn.edu/
or is
http://ms.gis.umn.edu/ for 4.6.0 and
http://mapserver.gis.umn.edu/ for 4.2.?

and finally in the mapscript documentation at http://ms.gis.umn.edu/ it
shows using $layer->queryByFeatures as follows:

queryByFeatures( mapObj map, int slayer )

but when I include the mapObj in the parameters I get a "invalid _handle_
property" error - even on the machine with 4.6.0. Is there some explanation
for this? Could it be related to the previously noted bugs with queries on
dynamically loaded layers? Should I be including the mapObj parameter? It
seems to function (but with the wrong count as noted above) without the
mapObj parameter.

I will continue to play with this . . . perhaps make the districts layer
part of the map file and see what happens on the 4.6.0 machine.

thanks
tim

Tim Norris
UC Industry-University Cooperative Research Program
Berkeley CA