Problem with gmap zoom

[leiras]

Hi,

i'm using gmap in my apliccation, but i'm having a problem with the zoom.
Look at a piece of my code:

<rich:gmap zoom="#{myBean.zoomMapa}" binding="#{myBean.mapaRastreamento}" oninit="loadPoints()"/>

Wen i change the zoom of the map on the page, the new value of zoom is not passed to the attribute "myBean.zoomMapa". Is it possible? How can i do that?
One solution could be create a javascript function that returns the correct zoom value, like this:

 function getZoom() {
 return map.getZoom();
 }

But i don't know how to call this function from myBean and get the return value.
Any sugestions?


Thanks a lot, and sorry about my english.

[sergeysmirnov]

zoom attribute is read-only. When you change zoom on the client, it does not update the bean on the server.
If you want to synchronize them, you need to do it explicitly. Use a4j:jsFunction that is called from the gmap callback function. Refer to the gmap manual how to add your callback function on zoom changes

[leiras]

Sergey,

where should be my function that is activated when the zoom changes?
On the client or on the server side?
Do you have some example?


Thank you for your help.

[sergeysmirnov]

gmap itself is a pure client-side widget. It has no idea about the server side. So, all function are on the client.

[leiras]

Please take a look at my current code.

I added an event to the map that fires wen the zoom changes:

GEvent.addListener(map, "zoomend", function() {
 zoomChanged();
});

And here are my JSFunctions

 function getCurrentZoom() {
 return map.getZoom();
 }

 function zoomChanged() {
 alert('Zoom Changed : '+getCurrentZoom());
 }

So, when i change the zoon, apears the message "Zoom Chenged : zoomValue".

Now i need to pass the zoom value to my bean.
I tryed to do this:

 <a4j:jsFunction name="zoomChanged">
 <a4j:actionparam name="xxx" value="getCurrentZoom()" assignTo="#{myBean.zoomMapa}" />
 </a4j:jsFunction>

and delete the piece of code

 function zoomChanged() {
 alert('Zoom Changed : '+getCurrentZoom());
 }

but it did not work.
The value assigned to "myBean.zoomMapa" was the String "getCurrentZoom()", and not the zoon value.
Any sugestions?

[sergeysmirnov]

<a4j:actionparam name="xxx" noEscape="true" value="getCurrentZoom()" assignTo="#{myBean.zoomMapa}" />

[leiras]

I found another solution:

GEvent.addListener(map, "zoomend", function() {
 zoomChanged(map.getZoom());
 });

<a4j:jsFunction name="zoomChanged">
<a4j:actionparam name="zc1" assignTo="#{myBean.zoomMapa}" />
</a4j:jsFunction>

Thank you very much for the help!

[v.bannur]

Hi Marcelo,

May I know where this event 'GEvent.addListener(map, "zoomend", function()' you kept in code?

I have kept like this as below and am getting JS error as map is undifined.

<a4j:outputPanel>

                    <script>

                    GEvent.addListener(this.map, "zoomend", function() {

                               zoomChanged();

                              });

  </script>

</a4j:outputPanel>