Question

I have a datasource that gets data from the server. It is then used in a datatable. I want to be able to filter the data in the table client-side, without making another call to the server.

// Data source definition
myDataSource = new YAHOO.util.DataSource("myurl");
myDataSource.responseType = YAHOO.util.DataSource.TYPE_JSON;
myDataSource.connXhrMode = "queueRequests";
myDataSource.responseSchema = {
    resultsList: "ResultSet.Result",
    fields: ["field1","field2"]
}

// Datatable definition
myDataTable = new YAHOO.widget.DataTable("container", myColumnDefs,myDataSource, {});

Answer 1

Subclass DataSource and override the sendRequest method so that you call the passed-in callback with your own filtered result set as the results argument.

filterDataSource=function(arg) {
    filterDataSource.superclass.constructor.call(this,arg);
}

YAHOO.extend(filterDataSource,YAHOO.util.XHRDataSource);

filterDataSource.prototype.sendRequest=function(request, callback) {
    var wrapCallBack=function (request,results,error) {
        // !!! do filtering on results here !!!
        callback.success.call(this,request,results,error);
    };
    filterDataSource.superclass.sendRequest.call(this,request, {
        success: wrapCallBack, argument: callback.argument
    });
}

And make your myDataSource a new filterDataSource instead of a new Yahoo.util.DataSource.

Disclaimer: this code probably doesn’t work as written; I ripped it out of some old working code and quite likely skipped over some critical piece. Still, I hope it conveys the basic idea.