[OpenLayers-Users] Re: problems with a popup sans marker

[Puneet Kishor]

Ok. I figured out the cause of the problem below, but I don't know the solution --

On Oct 17, 2011, at 5:06 PM, Puneet Kishor wrote:

> I am registering an click event to the map
> 
>    map.events.register("click", map, popUp);
> 
> Then querying the db for the feature at the point of click
> 
>    popUp: function(e) {
>    	
>    	// From google to latlng
>        var lonlat = map.getLonLatFromViewPortPx(e.xy).transform(
>        	proj.google,
>        	proj.latlng
>        );
> 
>        $.ajax({
> 	        url: "http://server/feature.json",
> 	        data: {lng: lonlat.lon, lat: lonlat.lat},
> 	        type: "GET",
> 	        dataType: "jsonp",
> 	        success: function(data) {
>                var html = unravel_data(data);
> 		    	var c = map.getLonLatFromViewPortPx(e.xy);
> 
> 		        map.addPopup(
> 			        new OpenLayers.Popup.Framed(
> 			            "featurePopup",
> 			            new OpenLayers.LonLat(c.lon, c.lat),
> 			            new OpenLayers.Size(200, 150),
> 			            html,
> 			            null,
> 			            false,
> 			            null
> 			        )
> 		        );  
> 			}
> 	    });
>    }
> 
> But, instead of the popup, I get the following in my console
> 
> 	OpenLayers.js: 2367: TypeError: 'null' is not an object (evaluating 'this.positionBlocks[this.relativePosition]')
> 	
> Note that I want a popup without a marker or a vector feature. So, I have two questions --
> 


I believe, in order to have a Framed popup, I need to pass in an anchor which, per the docs, "must expose a ‘size’ OpenLayers.Size and ‘offset’ OpenLayers.Pixel (generally an OpenLayers.Icon)."

If I change the above to just `new OpenLayers.Popup()` then it works fine, but that is not what I want. How do I draw an Framed or FramedCloud popup without creating an icon? I simply want to click on a polygon and create a popup anchored to the point of click.


> 1. How can I successfully draw the above popup?
> 2. Can I register the event to a layer instead of to the map? The reason is, this particular layer doesn't cover the entire map, so I want the feature query to be performed only when the user clicks on the layer.
> 
> --
> Puneet Kishor