Question

i’d like to know if there is any way to do autocomplete in rails 3 from a csv file. i’m trying to do this with controller render the HTML partial (i’m not sure about that).Posting the code below. i’m new to rails , your help is much appreciated

class CsvreaderController < ApplicationController
  def search_csv
    unless params[:search_no].nil?
      @winner_attrs = nil

      @search_no = params[:search_no]
      @file_path = params[:file_path]

      File.open(@file_path, "r") do |infile|
        p "file opened in read mode"

        while (line = infile.gets)
          attrs = line.split("\t")

          if attrs[0].to_i.equal? @search_no.to_i
            p "match found"
            p @winner_attrs = attrs

            respond_with do |format|
              format.html do
                if request.xhr?
                  render :partial  => "search_csv",
                         :locals   => { :result => @winner_attrs },
                         :layout => false,
                         :status => :created
                else
                  redirect_to "search_csv"
                end
              end
            end

          end
        end
      end

    end
  end
end

View file:

<script>
$('#csv_form').bind('ajax:success', function(evt, data, status, xhr) {
  $('#result').html(xhr.responseText);
});
</script>

<%= form_tag( { :action => 'search_csv' },
              :remote => 'true',
              :id     => 'csv_form'
    ) do
%>
  <%= text_field_tag 'search_no', nil, :class => 'textbox'  %>

  <%=  hidden_field_tag 'file_path', 'public/data/final_draw_till_10_Dec.csv' %>

  <%= submit_tag "Submit", :name => 'button', :class =>'button' %>
<% end %>

<div id="result"></div>

Answer 1

The biggest red flag here is that you’re opening and parsing the CSV file on every request. That’s an expensive operation and certainly not worth it. Autocomplete is essentially a search operation, and CSV files are not designed for searching. You should parse the CSV file only when it is created or changed, then store its data in a structure (e.g. a database with good indices) designed for searching,