Are there any good code examples for displaying preview images in the storefront?

Question

I can gather other info using folio.xxx, but can not find any good examples to use for preview images.  Tried folio.getPreviewImage() with no success.  Oh, I should mention it is version 2.  Plenty of examples for version 1.
Perhaps if I get a little more specific.
I am calling up the folios via:
       adobeDPS.libraryService.folioMap.addedSignal.add(function(folios) {
            for (var i = 0; i < folios.length; i++) {
                addFolio(folios[i]);
        }, this);
This eventually works into a function where I am gathering and displaying folio data:
     var productId = folio.productId;
    var html  = "<div id='" + productId + "'>";
        html +=     "<a href='#'><img class='shadow' width='120' src='' border=0 /></a>";
        html +=     "<br /><span class='bold'>" + folio.title + "</span>";
        html += "</div>";
    this.$el = $(html);
folio.title works fine to pull up the title, but I can no longer use folio.getPreviewURL in v2.  What code should I be using to set the src to the preview image?
Thanks

Answer 1

Have you looked at the default implementations of the library?
In FolioItemView's render function, there is a function(follow the nested functions!):
setTimeout(function(){ scope.loadPreviewImage() }, 100);
It references this function (this doesn't copy well):
loadPreviewImage: function() {
if (this.el.parentElement) {
var transaction = this.folio.getPreviewImage(135, 180, true);
transaction.completedSignal.addOnce(this.getPreviewImageHandler, this);
Going deeper, into the getPreviewImageHandler function is where you see the url value..
if (transaction.state == adobeDPS.transactionManager.transactionStates.FINISHED && transaction.previewImageURL != null) {
                              this.$el.find(".folio-thumb").attr("src", transaction.previewImageURL);
Within the example is also code for supplying a preview when the Adobe API is not available:
(Within the render function)
var json = this.model.toJSON();
$folioThumb.attr("src", json.libraryPreviewUrl);
If you're making any changes to where the preview is displayed, you can just swap out the class ".folio-thumb" to whatever the class (or id) is of the element you're wanting to render the preview in.