use elasticsearch for auto-suggest

app/controllers/crops_controller.rb

@@ -58,7 +58,7 @@ class CropsController < ApplicationController
 
     respond_to do |format|
       format.html
-      format.json { render :json => Crop.autosuggest(params[:term]) }
+      format.json { render :json => Crop.search(params[:term]) }
     end
   end
 

app/models/crop.rb

@@ -40,8 +40,8 @@ class Crop < ActiveRecord::Base
       tokenizer: {
         gs_edgeNGram_tokenizer: {
           type: "edgeNGram",
-          min_gram: 2,
-          max_gram: 20,
+          min_gram: 4,
+          max_gram: 10,
           token_chars: [ "letter", "digit" ]
         }
       },
@@ -256,13 +256,4 @@ class Crop < ActiveRecord::Base
     )
     return response.records.to_a
   end
-
-  # Crop.autosuggest(string)
-  # ActiveRecord search is used for auto-suggest instead of Elasticsearch.
-  # This is to avoid confusing users since the drop-down list for auto-suggest
-  # only caters for crop names at this time, not including scientific names or 
-  # alternative names.
-  def self.autosuggest(term)
-    where("name ILIKE ?", "%#{term}%")
-  end
 end