jQuery Grid Plugin - jqGrid

I have a situation where I was creating jqgrid empty initially with datatype as local and then later on adding nodes to jqgrid using addChildNode method. This is all done in client side javascript.

Now soon we have discovered that data is too much so javascript is taking too much time to load and we are getting warning as script is taking too long. I want to implement on demand data load , but whatever example I saw they all makes a call to server side for data load.

Do we have any such options where in I can implement on data data load and for data loading jqgrid will still make a call to client side javascript.