Zoom to custom extent - PHP

Wed Jan 26 14:44:14 EST 2005

Bill,
Hopefully this will be the last question I have - I feel I am close to
getting this now.  I followed your instructions - but the 'QuickZoom' is
not working yet (my normal rosa tools and legend works though).

Here's what I did:

1. added the OnChange command called QuickZoom() to the Select statement in
my app_contents.php

2. added the QuickZoom() function (in app_contents.php)
     - sets 'doQuickZoom' = 1
3. added the hidden variable (in app_contents.php)
     - sets 'doQuickZoom' = ""

Through error checking I noticed that the function is being called
properly, and the variable is being assigned the value from the function.

4. added the 'if statement' to my app.php:
If ( isset( $HTTP_FORM_VARS['doQuickZoom']) && $HTTP_FORM_VARS
['doQuickZoom'] == "1" )
{
set new extents..same code as before.
}

However, it seems that the 'doQuickZoom' does not retain it's value of 1,
instead it becomes "" again (each time I select from the 'quickmap' list
and page refreshes).
Even if I hardcode the hidden variable 'doQuickZoom' to be 1, and select
the 'quickmap', the mapextents do not change.
Does this make sense?

Kevin

On Wed, 26 Jan 2005 11:58:12 -0500, William Bronsema
<wbronsema at DMSOLUTIONS.CA> wrote:

>Hi Kevin,
>
>From the code you sent me, I see that you have added extra <form></form>
>tags around your select element.  You will need to remove those. (Perhaps
>that's why moving the select element makes it work now?)
>
>Adding an onchange event should work fine.  As for re-selecting the chosen
>quick zoom after the page has refreshed, there are many ways to do it, I
>just build the option list in php.  Something like this:
>
>***************************************
>$aszOpList = array('7120999,827999,7599999,1119999'=>'Lake Ontario',
>'7200000,833270,7291840,894520'=>'Niagara (ON)');
>$szOpList = '';
>foreach ( $ aszOpList as $key=>$szOp )
>{
>    // determine selected
>    $szTmpSelect = ( isset(  $HTTP_FORM_VARS['ViewRegion'] ) &&
>                     $HTTP_FORM_VARS [' ViewRegion '] == $key ) ?
>                        ' selected' : '';
>    // add next option
>    $szOpList.= '<option value="'.$key.'"'.$szTmpSelect.
>        '>'.$szOp.'</option>';
>}
>*****************************************
>
>That will build your list (be sure to add all the items) each time and
>select an item if you have zoomed to that extent.
>
>I do foresee another problem that you will have, that is each time you
>refresh the page, it will attempt to do a quick zoom because there will
>always be a value selected.
>
>Add a hidden textbox to signal a quick zoom request:
><input type="hidden" name="doQuickZoom" value="">
>
>In your onChange function set the value:
>
>document.forms[0].doQuickZoom.value = 1;
>document.forms[0].submit();
>
>Then back in PHP only execute the quick zoom when doQuickZoom is set to 1:
>
>If ( isset( $HTTP_FORM_VARS['doQuickZoom']) &&
>$HTTP_FORM_VARS['doQuickZoom'] == 1 )
>{
>        .....
>}
>
>HTH
>
>Bill
>______________________________
>William A. Bronsema, C.E.T.
>Applications and Software Development,
>DM Solutions Group Inc.
>
>> -----Original Message-----
>> From: Kevin Grootendorst [mailto:kgrootendorst at BAIRD.COM]
>> Sent: January 26, 2005 11:36 AM
>> To: MAPSERVER-USERS at LISTS.UMN.EDU; William Bronsema
>> Subject: Re: Zoom to custom extent - PHP
>>
>> Hi Bill,
>> The quick zoom seems to be working now, but the ROSA tools do not
respond,
>> nor does the legend/layer list.  I moved the code in the 'contents.php'
>> to 'higher up' in the file (no longer at bottom).  Once I select the
>> region
>> from the dropdown list, and click refresh, the map zooms to where it
>> should.  However, the list defaults back to the first option.  It would
>> also be nice to implement an 'onchange' event, so that I don't have to
use
>> the refresh button to zoom to the region (I'm wondering when things do
>> work, if adding a layer and refreshing will automatically zoom to the
>> first
>> extent in the 'View Region' drop down list).
>>
>> Kevin
>>
>>
>> On Wed, 26 Jan 2005 07:29:44 -0500, William Bronsema
>> <wbronsema at DMSOLUTIONS.CA> wrote:
>>
>> >Kevin,
>> >
>> >The javascript error is not preventing your map from zooming, something
>> else
>> >is.  There is likely some other PHP code that is resetting the extents
>> after
>> >your quick zoom code.
>> >
>> >The javascript error you are getting occurs because the function you
>> listed
>> >cannot find the hidden textbox called "QueryString".  Did you happen to
>> >remove it or move it outside of the form called "main"?
>> >
>> >Send me your app off-list and I will take a quick look.
>> >
>> >Bill
>> >________________________________________________
>> >William A. Bronsema, C.E.T.
>> >Applications and Software Development,
>> >DM Solutions Group Inc.
>> >
>> >
>> >> -----Original Message-----
>> >> From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU]
>> On
>> >> Behalf Of Kevin Grootendorst
>> >> Sent: January 25, 2005 2:52 PM
>> >> To: MAPSERVER-USERS at LISTS.UMN.EDU
>> >> Subject: Re: [UMN_MAPSERVER-USERS] Zoom to custom extent - PHP
>> >>
>> >> I've implemented the code, and now I'm even convinced it should work.
>> But
>> >> no such luck yet.  The debugging works just as it should, but when it
>> >> should 'quick zoom now', the map still draws to the project's max
>> extents.
>> >> However, I do receive a windows js error box indicating a problem in
>> the
>> >> app.phmtl file:
>> >>
>> >> 'document.main.QueryString.value' is null or not an object.
>> >>
>> >>
>> >> Here is my javascript from the .phtml file:
>> >>
>> >> <script language="javascript">
>> >> window.resizeTo(1024,768);
>> >> /**
>> >>  * This function runs after the form is done loading
>> >>  **/
>> >> function doneLoading()
>> >> {
>> >>     // show the query results page if query
>> >>     if ( document.main.QueryString.value != "" )
>> >>     {
>> >>         // complete the string
>> >>         document.main.QueryString.value = "?PrevStateKey=" +
>> >> document.main.PrevStateKey.value + "&INPUT_COORD=" +
>> >> document.main.INPUT_COORD.value;
>> >>
>> >>         // calculate the center
>> >>         if (document.all)
>> >>             var xMax = screen.width, yMax = screen.height;
>> >>         else if (document.layers)
>> >>             var xMax = window.outerWidth, yMax = window.outerHeight;
>> >>         else
>> >>             //var xMax = 640, yMax=480;
>> >>   var xMax = 800, yMax=600;
>> >>         var xOffset = (xMax - 510)/2, yOffset = (yMax - 390)/2;
>> >>
>> >> //QUERY RESULTS WINDOW
>> >>         // load the processing page
>> >>         mapquery = window.open('query.phtml' +
>> >>
>>
document.main.QueryString.value,'mapquery','scrollbars=yes,resizable=yes,w
>> >> id
>> >>
>>
th=800,height=600,screenX='+xOffset+',screenY='+yOffset+',top='+yOffset+',
>> >> le
>> >> ft='+xOffset+'');
>> >>
>> >>         // give it focus
>> >>         mapquery.focus();
>> >>
>> >>     }
>> >>
>> >>     // exit
>> >>     return;
>> >> }
>> >>
>> >> </script>
>> >>
>> >>
>> >> Could this somehow be preventing my php code from working?