[Chameleon] zoom clears legend

Thu Aug 5 13:55:18 EDT 2004

Thanks Paul.  My checkboxes weren't named legendlayername[] so I changed 
that and it works.  I assume this is a peculiarity of Chameleon because 
my original legend template worked in other situations.  Is there a 
place in the documentation I should have gone to find this out, or 
should I perhaps add a note to the bottom of 
http://www.maptools.org/chameleon/wiki/HTMLLegendExample?

Again, many thanks.

-Ken-ichi

Paul Spencer wrote:

> Ken,
>
> there is a specific thing you must do in the file called 
> vtm_legend_template.html which is to name the checkboxes used as 
> inputs to turn layers on and off.  And in particular, you must name 
> them all the same, and the name must be:
>
> legendlayername[]
>
> The square brackets are very important, it tells PHP to interpret the 
> checkboxes as an array of values.  If they are not included, PHP only 
> reports the first value and it is substantially more difficult to get 
> the other values.
>
> The other thing you must do is to give each checkbox a value of the 
> layer name, in particular:
>
> [leg_layer_name]
>
> Again, this is important, in this case, the MapServer legend template 
> processor replaces this with the actual name of each layer (see the 
> mapserver documentation on legend templates).
>
> The samples all use the following to build checkboxes for layer 
> visibility control ...
>
> <input type="checkbox" name="legendlayername[]"
> value="[leg_layer_name]"
>     [if name=layer_status oper=eq  value=1]CHECKED[/if]
>     [if name=layer_status oper=eq value=2]CHECKED[/if]>
>
> If this is not the problem, please send your vtm_legend_template.html 
> file along so I can take a look at it.
>
> Ken-ichi wrote:
>
>> Hi folks.  I just started using Chameleon 1.99b2 and I'm very very 
>> excited about it.  I've been trying to adapt the very minimal 
>> tutorial in the documentation section of the web site, adding a few 
>> widgets to see how they work.  However, when I add the legendtemplate 
>> widget and I zoom in, all the layers get turned off, resulting in a 
>> blank map.  Everything is fine when you first load the page, but when 
>> you zoom in or zoom out or update the map, the layers get cleared.  
>> Can anyone explain this behavior?  This does not happen with any of 
>> the samples applications in the samples/ directory.  I found that if 
>> I set the legendtemplate_reset parameter in the URL to 0 the legend 
>> returns to normal with all the layers turned on (it's normally 
>> blank).  I've included my template file below if it'll be of any help.
>>
>> Thanks in advance!
>>
>> <html>
>> <head>
>>   <title>Widgets</title>
>>   <link href="cwc2.css" rel="stylesheet" type="text/css">
>> </head>
>>
>> <body onload="CWC2OnLoadFunction()">
>>
>> <form>
>>
>>   <table>
>>   <tr>
>>       <td width="100">
>>           <table><cwc2 type="LegendTemplate" visible="true" 
>> embedded="true" template="vtm_legend_template.html" 
>> popupstyleresource="TextButtons" popupwidth="500" popupheight="400" 
>> status="false" menubar="false"/></table><br/>
>>           <cwc2 type="UpdateMap" visible="true" 
>> image="images/icon_update.gif" imagetip="update map" label="Update" 
>> imagewidth="24" imageheight="24">
>>               <image state="normal"/>
>>               <image state="selected"/>
>>               <image state="hover"/>
>>           </cwc2>
>>       </td>
>>       <td colspan="3" align="center">
>>           <CWC2 TYPE="MapDHTMLWidget" VISIBLE="true" width="400" 
>> height="300" AllowResize="true" MarqueeColor="#FF3333" 
>> MarqueeWidth="2" minscale="1"/>
>>       </td>
>>       <td valign="top">
>>           <CWC2 TYPE="ZoomIn" visible="true" 
>> Image="images/tool_zoomin_off.gif" 
>> ImageSelected="images/tool_zoomin_on.gif" 
>> ImageHover="images/tool_zoomin_over.gif" ImageTip="Zoom In" 
>> ImageWidth="24" ImageHeight="24" ToolSet="Navigation"/><br/>
>>            <CWC2 TYPE="ZoomOut" Visible="true" 
>> Image="images/tool_zoomout_off.gif" 
>> ImageSelected="images/tool_zoomout_on.gif" 
>> ImageHover="images/tool_zoomout_over.gif" ImageTip="Zoom Out" 
>> ImageWidth="24" ImageHeight="24" ToolSet="Navigation"/><br/>
>>            <CWC2 TYPE="PanMap" Visible="true" 
>> Image="images/tool_pan_off.gif" 
>> ImageSelected="images/tool_pan_on.gif" 
>> ImageHover="images/tool_pan_over.gif" ImageTip="Pan" ImageWidth="24" 
>> ImageHeight="24" ToolSet="Navigation"/>
>>   </tr>
>>   </table>
>>
>> </form>
>>
>> </body>
>>
>> </html>
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>