You can use the following to read remote data using a proxy:

// define a proxy

var proxy = new wijhttpproxy({

            url: "http://ws.geonames.org/searchJSON",

            dataType: "jsonp",

            data: {

                featureClass: "P",

                style: "full",

                maxRows: 12,

                name_startsWith: 'ab'

            },

            key: 'geonames'

        });

// define a reader

var myReader = new wijarrayreader([

    {

        name: 'label',

        mapping: function (item){

            return item.name + (item.adminName1 ? ", " + item.adminName1 : "") + ", " + item.countryName

        }

    },

    {name: 'value',mapping: 'name'}]);

// create datasource

var datasource = new wijdatasource({

    reader: myReader,

    proxy: proxy,

    loaded: function (data){

        // read items.

        var items = data.items;

    }

});

// trigger load.

datasource.load();