I'm extending the "Add Shapefile" example to allow the user to select a column from the shapefile by which to set the symbology of the layer added...Taking a featureCollection, extracting field names to populate a dijit.form.ComboBox:This part works:
function populateColumnDropDown(featureCollection){
 names = featureCollection.layers[0].layerDefinition.fields;
 var fieldNames = [];
 for(i = 0; i < names.length; i++){
  if(names.name != "FID"){
   fieldNames.push({name:names.name});
  }
 }
 var dataItems = {
         identifier: 'name',
         label: 'name',
         items: fieldNames
 };
 var store = new dojo.data.ItemFileReadStore({data:dataItems});
 dijit.byId("columnInput").store = store;
}
<select id="columnInput" dojotype="dijit.form.ComboBox" style="width:150px;" value="Select Column" title="Select Column To Symbolize" fetchProperties="{sort:[{attribute:'name', descending:false}]}" onChange="setSymbology();" disabled></select>
 
No errors are thrown until I click the comboBox to see the values. Then it throws a: Object has no method 'query' error.Any thoughts?