[OpenLayers-Users] export map issues

[DevHour]

Eric Lemoine <eric.lemoine at camptocamp.com> wrote ..
> On Thursday, August 12, 2010, DevHour <jamie at devhour.net> wrote:
> > Currently I am trying to export maps to a canvas element by using the example
> posted at http://trac.openlayers.org/browser/sandbox/camptocamp/canvas/openlayers/examples/exportMapCanvas.html
>  by tsauerwein. So far i've grabbed that html file and the exportMap.js file. The
> issue i'm having is that it won't export the WMS layers, although it will export
> vector layers.
> >
> > I've gone through and tried to debug the script (using Firebug) and this is the
> part where its failing:
> >
> > ExportMap.js - line 128 through 136
> > exportGridLayer: function(layer) {
> >         if (layer.useCanvas != OpenLayers.Layer.Grid.ONECANVASPERLAYER) {
> >             return;
> >         }
> >
> >         if (layer.canvas != null) {
> >             this.drawLayer(layer.canvas);
> >         }
> >     },
> >
> > Now it is passing the layer correctly into the function but layer.useCanvas is
> undefined. So it'll automatically pass over that first if statement, and also layer.canvas
> is also undefined there so it'll pass over the next if statement as well. Meaning
> that the layer won't get passed through to the draw canvas. Like I said it works
> for vectors, just not the others. Is there any reason why these 2 properties (useCanvas
> and canvas) are both undefined? am I missing a reference to something?
> >
> > Any help I get will be greatly appreciated!
> 
> 
> This sandbox also includes code for displaying tiles using canvas. And
> it looks like only WMS layers that use canvas with the
> ONECANVASPERLAYER mode can be exported.
> 
> 
> Hope it helps,
> 
> -- 
> Eric Lemoine
> 
> Camptocamp France SAS
> Savoie Technolac, BP 352
> 73377 Le Bourget du Lac, Cedex
> 
> Tel : 00 33 4 79 44 44 96
> Mail : eric.lemoine at camptocamp.com
> http://www.camptocamp.com
> 

Well currently i'm strictly using the code that was provided, including the html file. The WMS base layer that is provided looks like so;

var wmsBase = new OpenLayers.Layer.WMS("OpenLayers WMS",
                    "http://labs.metacarta.com/wms/vmap0?",
//                    "proxy.cgi?url=http://labs.metacarta.com/wms/vmap0?",
                    {
                        layers: 'basic'
                    },
                    {
                        useCanvas: OpenLayers.Layer.Grid.ONECANVASPERLAYER
                    });

As you can see useCanvas is defined and set to ONECANVASPERLAYER. This is one of the reasons why i'm stuck, before useCanvas is defined yet still showing as undefined.