Forums

Hi everyone,

I have a view that renders a list of selectable items. When a user clicks on an item, the item is no longer selectable. This occurs by updating the model and re-rendering the view every time a user clicks on an item.

The problem I'm running into is that the list is long and I need to make it scrollable. But when I scroll down to select an item (at the end of the list) and the view rerenders, then I'm back at the top of the list.

I'm looking for some suggestions on how I could keep the current scroll position across rendering the view.

Thanks.

I haven't thought of that. It sounds like a decent solution for the current predicament I'm in. Hmmm... wasn't there a scroll into view utility that YUI provided...

The `scrollIntoView()` method will work, like you figured out; but you might also want to consider not re-rendering the _entire_ list if you're just updating one item in that list.

Daniel,

ModelLists are ordered, so if your view is already rendering out a ModelList, you could simply select the n-th child node at the particular index the updated model is at in the model list, and update that node.

Eric,

Based on your post, I ended up refactoring my code given the hunch I had. I like this approach. I had to move the logic that actually deals with the nodes and altering the state into the model and during the view's init, the models in the model list are initialized with the css selector to create a node instances.

So on a click event, the callbacks
1. parse the model's id from the node clicked
2. grab the model by ID from the modelList
3. call model.toSelectedState() or model.toAvailableState() - the model has the css selector and can now change the single node and there is no need to render the entire view again.

I know the Y.App uses the MVVM paradigm, but working with MVVM is still new to me. I'm so used to working with MVC or using a Presentation Model with MVC. But given the architecture that Y.App lends itself to (MVVM), I guess it's fine that the model.toSelectedState() or model.toAvailableState() are in the Model class and not the Y.View or some form of a controller...