[Mapserver-users] Re: Setting scale of map while using dbox

[Emilio Mayorga]

Jason,

I have a dbox application where the functionality you mention is working 
  just fine. It's borrowed from a couple of other applications, of 
course... Anyways, here's the gist:

** Here's the FORM element:
<form name="scaleform" action="javascript:void(0)" onSubmit="return 
change_scale()">
<input type="submit" value="Zoom to Scale:"> 
<input type="text" name="scale" maxlength="10" size="10">
</form>

** Which calls the change_scale function on submit:
function change_scale() {
   var x = (ms.extent[0] + ms.extent[2])/2.0;
   var y = (ms.extent[1] + ms.extent[3])/2.0;
   ms.zoomscale(x, y, document.scaleform.scale.value);
   return false;
}

Don't ask me to explain or justify every bit of code; in some cases I've 
forgotten, in other cases I simply never bothered to learn why things 
were the way they were in the code I borrowed.

Good luck.

-Emilio
------------------

I was wondering if anyone might be able to tell me how to go about 
sumbitting a fixed scale (ie: typed in by user) to mapserver when using 
the dbox stuff.

Below is an idea of how to get the scale set but I do not see where 
"scale" is used in the mapserv.js file. I know a parameter can be passed 
directly to mapserv cgi and I also noticed functions such as "function
Mapserv_setextentfromscale(x, y, scale)" but I dont see where I get my
coordinates from (ie: mapx, mapy if just using regular html).

I just have a refresh button at the moment to press once the scale is set.

<font class="fontbold">Scale=> 1:</font><input class="inputfield" 
size="10" maxlength="10" type="text" name="scale_ratio" title="scale 
ratio" alt="scale ratio" value="" onChange="ms.scale=this.value">

Would the right was to do this be to call the above function directly 
with the x, y and scale?