ListPaging startParam with YouTube Jsonp

[kenono]

I use a list on my app to display content from my YouTube feed, I get the data using Jsonp and this is fine.
I am trying to use the ListPaging plugin and I'm close to getting it to work.

The issue is that by default the startParam is set to 0 and I need to start at 1 (and then go to 11, 21, etc., rather than 0, 10, 20, etc) - this is because YouTube uses a one-based index.

The list starts empty (as the startParam being 0 is invalid, but then loads the content when scrolled as 10 is valid). I hope this is clear.

My question: is there a way I can set the startParam (which is start-index for the YouTube Json) to 1 initially and then have it go up by 10 each time?

Finally, here is the code for my store:

Ext.define('App.store.YouTubeStore', {    extend:'Ext.data.Store',
    config: {
        autoLoad: true,
        
        remoteFilter:false,
        sortOnFilter:false,
        clearOnPageLoad: false,  // This is true by default
        pageSize: 10,            // This needs to be set for paging
        
        fields: ["totalItems", "startIndex", "itemsPerPage", "title", "description", "id", "likeCount", "ratingCount", "viewCount", "commentCount", {
            name: 'thumbnail',
            mapping: 'thumbnail.hqDefault'
        },{
            name: 'link',
            mapping: 'player.default'
        }],
        proxy:
        {
            type: 'jsonp',
            url: 'http://gdata.youtube.com/feeds/api/users/<USER>/uploads?alt=jsonc&v=2',
            
                       startParam: 'start-index',
                       limitParam: 'max-results',
            
            reader:
            {
                type: 'json',
                encodeRequest: true,
                rootProperty: 'data.items'
            }
        }
    },
});

[mitchellsimoens]

You can listen to the beforeload and set the start on the operation using the setStart and getStart methods.