[ka-Map-users] kaxmloverlay issues and workarounds

[Paul Spencer]

I haven't looked at how this was implemented but if it is using  
xmlhttprequest then it is possible to use POST to avoid urls that  
don't work with GET

Cheers

Paul

On 23-Apr-06, at 9:37 PM, Mark Wright wrote:

> I noticed an issue when drawing a linestring with kaxmloverlay where
> it would not connect the last two points in the line. The workaround I
> am using is to repeat the last point. I'm wondering if this is a known
> bug or if there's something wrong with my xml, which I copied below:
>
> <overlay>
> <point id="line1" x="-698" y="4165" redraw="true">
> <linestring stroke="3" opacity="1.0" color="#cc0000">-698 4165, 1193
> 3613, 2787 3530, 3467 2819, 2787 2146, 1155 2152, 558 2730, -831 3784,
> -933 4095, -1454 4356, -1454 4356</linestring>
> </point>
> </overlay>
>
> As you can see this includes my workaround where the last coordinate
> is repeated.
>
> I have also run into a problem where I have lines that are too long to
> be passed to the drawgeom.php script. Basically, it's longer than the
> querystring can handle. My workaround here has been to make the script
> I use to generate the above xml also create the same linestring that
> is sent to the drawgeom.php script and store it inside
> $_SESSION['kaLine']. I basically translated the
> kaXmlFeature.prototype.readCoordinates javascript function into a php
> function. This function assumes the line is already broken into an
> array of "x y" coordinates and the first thing it does is to repeat
> the last coordinate so that the last line segment will be drawn.
>
>
> function makeKaXMLline($line,$scale)
> {
> 	$line[] = $line[count($line) - 1];
>
>  	$pp = $line;
> 	$cxmin = 0;
> 	$cymax = 0;
> 	for ($i=0; $i<count($pp); $i++) {
> 		$s = $pp[$i];
> 		$xy = explode(' ',$s);
> 		if ($xy != null) {
> 			$x=$xy[0];
> 			$y=$xy[1];
> 			$cx[] = $x;
> 			$cy[] = $y;
> 			if ($i==0 || $x<$cxmin) $cxmin = $x;
> 			if ($i==0 || $y>$cymax) $cymax = $y;
> 		}
> 	}
> 	
> 	// Normalize the coordinates
> 	for ($i=0; $i<count($pp); $i++) {
> 		$x = round(($cx[$i] - $cxmin) / $scale);
> 		$y = round(($cymax - $cy[$i]) / $scale);
> 		if ($i>0) $coords .= ",";
> 			$coords .= "$x,$y";
> 	}
> 	return $coords;
> }
>
>
> Then in the drawgeom.php script I start a session and after all the
> variables are set from the querystring (around line 90) I add
>
> $coords = ($type == 'L' && $_SESSION['kaLine'])?$_SESSION['kaLine']: 
> $coords;
>
> Now I can have as many points in my line as I want. However, none of
> this would be necessary if the line was sent to drawgeom.php as POST
> rather than GET. Is this possible?
>
>
>
> Mark
>
>
> --
> Have fun or die trying - but try not to actually die.
>
> _______________________________________________
> ka-Map-users mailing list
> ka-Map-users at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/ka-map-users

+-----------------------------------------------------------------+
|Paul Spencer                           pspencer at dmsolutions.ca   |
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|Applications & Software Development                              |
|DM Solutions Group Inc                 http://www.dmsolutions.ca/|
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