never mind! I have determined that I am doing something wrong on my end :-)
now to figure out what...
thanks again!
percy
percy wrote:
I've stripped the code down to the bare minimum. The errant behavior
persists!
Geologic faults turn on in the map (and show up in the DIV resulting
from a map->draw()) at a scale of 500000. If I then zoom in sort of
slowly, drawing a zoom rectangle just slightly smaller than the screen
each time, they'll show up the legend at around 250000. The legend gets
redrawn on every zoom.
If I use our pre-defined zoom levels, the faults don't show up at
250000, but they do show up at 100000. It sometimes seems like the
legend is a step behind.
Same behavior if I use a normal legend instead of legend template.
Just for fun (!) I tried turning on legend items (naming the classes)
for all of the other layers to see how they behaved. I had legend items
coming and going at just weird times. This was what led me to think that
it might be known bug in MapServer version 4.8.0-rc2
Below is the stripped down code, it get's called by a little AJAX-y
javascript function that stuffs the results into the innerhtml on a
popup tab. Hmmmmmmm, I wonder if the AJAX-y stuff is interfering
somehow... :-)
<?php // legend.php
// set error reporting
ini_set("display_errors", 1);
ini_set("display_startup_errors", 1);
error_reporting (E_ALL);
header("Content-type: text/html charset=utf-8");
if (isSet ($_REQUEST['extent']) &&
isSet ($_REQUEST['mapfile']) &&
isset($_REQUEST['layers'])
) {
$extent = $_REQUEST['extent'];
$mymap = './map/' . $_REQUEST['mapfile'];
$layers=$_REQUEST['layers'];
} else {
print "<p>Invalid query string: ".$_SERVER['QUERY_STRING']."</p>";
exit;
}
//first set the exyent, this should take care of the scale dependencies
$map = ms_newMapObj($mymap);
if ($extent['x1'] && $extent['y1'] &&
$extent['x2'] && $extent['y2']) {
// set the extent
$map->setExtent($extent['x1'], $extent['y1'], $extent['x2'],
$extent['y2']);
}
//now handle turning the layers on or off
if (count($layers)>0) {
for ($i=0; $i<$map->numlayers; ++$i) {
$oLayer=$map->getLayer($i);
if (in_array($oLayer->name,$layers)) {
$oLayer->set("status",MS_ON);
} else {
$oLayer->set("status",MS_OFF);
}
}
}
$my_html=$map->processLegendTemplate(null);
echo $my_html;
?>
Daniel Morissette wrote:
The code that you included in your last email seems to be missing the
stuff that handles the zoom. i.e. a comment suggests that you create a
$extent_obj for this, which is either initialized from the values in
the $extent[] array, or from the $map->extents which have just been
set from the contents of the $extent[] array, so in both case you get
more or less the same result minus the width/height ratio adjustment
that MapServer does automatically on $map->setExtent()... and there is
nothing to adjust the extents to reflect the last zoom operation and
pass that to $map->setExtents().
What does the $extent[] array contain when this code starts being
executed? Is it the extents before or after applying the zoom?
Daniel
percy wrote:
Thanks Daniel, but I've been testing this pretty hard as you can see
from the code snippet below (testing parts are commented out). The
layers are getting turned on and off correctly in the section right
before the call to processlegendtemplate...
$map = ms_newMapObj($mymap);
if ($extent['x1'] && $extent['y1'] &&
$extent['x2'] && $extent['y2']) {
// set the extent
$map->setExtent($extent['x1'], $extent['y1'], $extent['x2'],
$extent['y2']);
// set up extent object for use in zoom (!?!?)
$extent_obj = ms_newRectObj();
$extent_obj->setExtent($extent['x1'], $extent['y1'],
$extent['x2'], $extent['y2']);
} else {
$extent_obj = ms_newRectObj();
$extent_obj->setExtent ($map->extent->minx, $map->extent->miny,
$map->extent->maxx, $map->extent->maxy);
}
//now handle turning the layers on or off
if (count($layers)>0) {
//echo "I see more than 0 layers\n";
for ($i=0; $i<$map->numlayers; ++$i) {
$oLayer=$map->getLayer($i);
// echo "got layer number".$i;
if (in_array($oLayer->name,$layers)) {
$oLayer->set("status",MS_ON);
// echo "turning on layer ".$oLayer->name;
// echo $oLayer->status;
} else {
$oLayer->set("status",MS_OFF);
// echo "turning OFF layer ".$oLayer->name;
}
}
}
$my_html=$map->processLegendTemplate(null);
//echo $_SERVER['QUERY_STRING'];
echo $my_html;
Daniel Morissette wrote:
percy wrote:
When you zoom in on the map, the scale dependencies all work great
for the map, but the legend is always out of whack. I am using
php/mapscript to generate a processlegendtemplate() request. For
debugging this issue, I have also tried just a straight
drawlegend() request and I get similarly odd behavior. The geologic
faults, which are set to show up at a scale of 1:500,000 don't show
up in the legend until zoomed in to around 1:100,000. (though
sometimes if I zoom in small increments, they'll show up sooner...)
The problem could be related to the order in which you make calls in
your PHP script. The legend object uses the last calculated scale in
its tests to decide which layer/classes to include in the legend, so
if you call processlegendtemplate() before the extents and scale
have been updated to reflect the last zoom operation then you could
get this kind of behavior.
I just did a quick check in the code and $map->setExtent() does
update the scale value, so if you call that with the right extents
before processing the legend then you should be fine.
Daniel
--
David Percy
Geospatial Data Manager
Geology Department
Portland State University
http://gisgeek.pdx.edu
503-725-3373
