Query shapes in certain extent

[Lowell Filak]

The following message was sent by G-Net Consulting
<joelf at GNETCONSULTING.COM> on Wed, 1 Sep 2004 13:31:58 -0400.

> Lowell/List:
>
> I updated my code, as you suggested.  The results are coming out
> now, but seem to be a page behind.  An example:
>
> I have states that have points in each.  So, say you choose
> Florida.  It should have 247 points.  If you then choose Alaska,
> it now says 247 (which was Florida from before).  If you go
> to another state (that should have 0, it finds 7).
>
> I'm also assuming the index pulled is the one in sensors.shx?  I
> really need to pull the ID from sensors.dbf.
>
> I'm attaching my code and map file segment.  Any/all suggestions
> would be appreciated.
>
> Thanks!
>
> MAP File ========================
>
>   LAYER
>     NAME "sensors"
>     STATUS ON
>     DATA "./sensors"
>     TYPE POINT
>  CLASSITEM "ID"
>     SYMBOLSCALE 10
>     LABELITEM "ID"
>     LABELCACHE ON
>     POSTLABELCACHE TRUE
>  TEMPLATE "sensors.html"
>     METADATA
>       "DESCRIPTION" "GMF Sensors "
>    "RESULT_FIELDS" "ID"
>     END
>     CLASS
>       NAME "Sensors"
>    TEMPLATE "sensors.html"
>       STYLE
>         SYMBOL 4
>         COLOR 0 255 0
>         OUTLINECOLOR 0 0 0
>         BACKGROUNDCOLOR 255 255 255
>         SIZE 3
>         MINSIZE 3
>         MAXSIZE 100
>       END
>  END
> END
>
> PHP Code: ========================
>
> // get our sensor layer
>   $myLayer = $gmfMap->getLayerByName("sensors");
>   $myLayer->set("status", 1);
>
>   // create a rectangle object to search in and set the extent (from
> querystring params)
>   $rectObj = ms_newRectObj();
>   $rectObj->setextent($_GET["minx"], $_GET["miny"], $_GET["maxx"],
> $_GET["maxy"]);
>
>   // query the points in the chosen space
>   @$myLayer->queryByRect($rectObj);
>
>   // find out how many results we found
>   $shpCount = $myLayer->GetNumResults();
>
>   // loop through our results, and process accordingly
>   if ($shpCount) {
>    for ($i = 0; $i < $shpCount; $i++) {
>     // get our result
>     $layerIndex = $myLayer->getResult($i);
>     $arrShapes[] = $layerIndex->shapeindex;
>    }
>   }
>
> Joel
>
> ----- Original Message -----
> From: "Lowell Filak" <lfilak at medinaco.org>
> To: "G-Net Consulting" <joelf at GNETCONSULTING.COM>;
> <MAPSERVER-USERS at LISTS.UMN.EDU>
> Sent: Wednesday, September 01, 2004 9:20 AM
> Subject: Re: [UMN_MAPSERVER-USERS] Query shapes in certain extent
>
>
> > The following message was sent by G-Net Consulting
> > <joelf at GNETCONSULTING.COM> on Tue, 31 Aug 2004 14:50:11 -0400.
> >
> > > Hello list:
> > >
> > > What is the best way to access the shapes and locations of
> > > points marked within a given map?  I have several hundred
> > > points I need to find that are displayed from a given layer.
> > > What's the best way to accomplish this?
> > >
> > > I currently have a layer that has over 5,000 points marked
> > > through the US.  As they drill down, I plan to use JavaScript
> > > to display information about each one.  In the dbf file, I have
> > > an ID that corresponds to an ID in a MySQL table.  I just
> > > to get the ID"s of just the one displayed inside the chosen
> > > extent.
> > >
> > > I'm using PHP 4.3.3 with MapScript 4.2.1 on Redhat 9.
> > >
> > > Thanks in advance.
> > >
> > > Joel
> >
> > Joel;
> >
> > If you create a rectObj using the specified extent you can use
> > layer->queryByRect to query the point(s) into the layer resultcache and
> > then use layer->getResult & resultCacheMemberobj->shapeindex to retrieve
> > the shapeindex for each of the resulting points.
> > If your id in the mysql database corresponds to the shapeindex your all
> > set. If not then you will need to use an xbase module to pull the nth
> > (shapeindex) record from the dbf file to obtain the id that links to the
> > id in the mysql table.
> >
> > Lowell
> >


Joel;

If the results look as if they are one page behind is it because the
get/put that is sent is a "page behind"?
You are correct that the index pulled is not from the dbf. But it is the
corresponding record number in the dbf.

HTH

Lowell