Re-center map on supplied XY

[Steve Lime]

Everything's possible... ;-)

You probably are running into a conflict between navigating by click and coordinate. I'd have to see the interface to be sure. But it is likely that you are telling the software to recenter 2 ways. MapServer gives priority to the click-based nav. You can fix this a couple of ways:

1) use a second form on the page for the coordinate nav so that no conflict exists, it might look like this in your template:

<form action="/cgi-bin/mapserv">
  <input type=text name=mapx> lon  <input type=text name=mapy> lat <input type=submit value="go">
  <input type=hidden name=map value="[map]">
  <input type=hidden name=scale value="[scale]">
  <input type=hidden name=layers value="[layers]">
</form>

The only problems with this approach is that the layers are set when the page loads so if the user changes them and then sets a point those changes are lost. Secondly, your design might not allow you to setup a second form like this.

2) when you submit the form, check the values of form vars called lat and lon using javascript and if they look valid then craft a call to mapserver using those values. Like so (assuming the form is named 'ms'):

function submitMe() {
  if(document.ms.lat.value && document.ms.lon.value)
    window.location.href = '/cgi-bin/mapserv?map=[map]&scale=[scale]&layers=[layers_esc]&mapxy=' + document.ms.lon.value + '+' + document.ms.lat.value;

  return true;  // submit as normal
}

This approach is the most flexible but requires javascript. I would use lat/lon for the form element names to avoid any conflct with standard MapServer parameter names.

This is off the top of my head but the code above should get you started.

Steve

>>> Chip Taylor <work at XWB.COM> 10/27/05 9:10 AM >>>
I have a map with no scripting (all CGI-based with HTML) that I'd like to
provide a way for the user to enter a longitude and latitude in text boxes,
hit submit, and recenter the map with current layers, size, etc on the
supplied latitude and longitude.  I know that the CGI passes the variables
mapx and mapy that tells you where the current map is centered, but if I
create a textboxes with id's and names of mapx and mapy, after these are
filled in with the desired values and the form is submitted the map is not
centered on these coordinates.  What am I doing wrong?  Is what I want
possible?

Chip Taylor
Prepared Response, Inc. 
1127 Broadway Plaza, Suite 204
Tacoma, WA  98402
O 253.272.1730
M 253.948.2525
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