SC.ImageView throws error when setting value

When setting the value property of a subclassed SproutCore image view (SC.ImageView) a runtime error is thrown:

In Safari and Firefox:

TypeError: Result of expression 'elem.setAttribute' [undefined] is not a function.

In Chrome:

Uncaught TypeError: Object DigDeeper.ZoomLayerView:sc398 has no method 'setAttribute'

The error occurs in /static/sproutcore/foundation/en/current/javascript.js on the following code (line 4735):

// convert the value to a string (all browsers do this but IE) see 
// #1070 (jQuery)
if ( set ) elem.setAttribute( name, "" + value );

The image is loaded but does not display.

I am using the current version of sproutcore from the ruby gem (appears to be 1.4.5).

How can I re开发者_运维技巧solve this issue?

Here is the source:

DigDeeper.ZoomTileView = SC.ImageView.extend({

    // Properties
    zoom: null,
    layer: null,
    scaleIndex: null,
    column: null,
    row: null,

    // Overridden properties
    classNames: [ 'zoom-tile-view' ],

    // Computed properties
    scale: function () {
        return Math.pow( 2, this.get( 'scaleIndex' ) );
    }.property( 'scaleIndex' ),

    id: function () {
        return "%@.%@.%@.%@".fmt(
            DigDeeper.ZoomTileView.zeroPad( 0, 5 ),
            DigDeeper.ZoomTileView.zeroPad( this.get( 'scale' ), 0 ),
            DigDeeper.ZoomTileView.zeroPad( this.get( 'column' ), 0 ),
            DigDeeper.ZoomTileView.zeroPad( this.get( 'row' ), 0 )
        );
    }.property('layer','scaleIndex','column','row').cacheable(),

    value: function () {
        return "/static/dig_deeper/en/current/resources/images/%@.png".fmt( this.get( 'id' ) );
    }.property( 'id' ),

});

You have a trailing comma on your value method.

Removing it might solve you issue.

What does your SC.ImageView design look like? Here is an example of something I do to pop up a little progress spinner when a really long server call is processing:

validateProgressImage: SC.ImageView.design({
  layout: { top: 63, left: 150, height: 16, width: 16 },    
  value: sc_static("images/ajax-loader.gif"),
  canLoadInBackground: true,
  useCanvas: NO,
  useImageQueue: NO,
  isVisible: YES
}),

My ajax-loader.gif file is located in my resources/images directory.