app.rb

require 'lib/cleared_check'
require 'lib/cleared_check_updater'
require 'rubygems'
require 'fastercsv'
require 'sinatra'
require 'json'
require 'haml'


@@cleared_checks = ClearedCheckUpdater.read

get '/' do
  haml :upload
end

get '/search' do 
  content_type :json
  @matching_checks = []
  if params[:amount]
    amount = (params[:amount].to_f * 100).round
    @matching_checks = @@cleared_checks.select{|check| check.amount == amount}
  end
  if params[:check_number]
    check_number = params[:check_number]
    if @matching_checks.size > 0
      @matching_checks = @matching_checks.select{|check| check.check_number == check_number}
    elsif
      @matching_checks = @@cleared_checks.select{|check| check.check_number == check_number }
    end
  end
  @matching_checks.to_json
end

post '/upload' do
  unless params[:file] &&
         (tmpfile = params[:file][:tempfile]) &&
         (name = params[:file][:filename])
    @error = "No file selected"
    return haml(:upload)
  end
  STDERR.puts "Uploading file, original name #{name.inspect}"
  ClearedCheckUpdater.update(tmpfile)
  @@cleared_checks = ClearedCheckUpdater.read()
  "Upload complete"
end

cleared_check.rb

class ClearedCheck 
    
  attr_accessor :amount,:check_number,:account,:posted_on,:sequence,:image_location,:image_offset,:image_length,:image_type
  
  def initialize options
    @amount = options["amount"].gsub(",","").to_f*100.round
    @check_number = options["check_number"]
    @posted_on = Date.parse(options["posted_on"])
  end
  
  def to_json(options)
    { :amount => @amount/100,
      :check_number => @check_number,
      :posted_on => @posted_on }.to_json
  end
  
end

cleared_check_updater.rb

class ClearedCheckUpdater
  
  def self.update(tmpfile)
    filesize = File.size(filepath)
    file = File.open(filepath, "a")
    tmpfile.lines.each_with_index do |line,index|
      #don't write first row headers unless file is empty
      file.write(line) if(index > 0 || filesize < 100)
    end
    file.close
  end
  
  def self.read
    cleared_checks = []
    FasterCSV.foreach(filepath, :headers => true) do |line|
      cleared_checks << ClearedCheck.new(line)
    end
    cleared_checks
  end
  
  def self.filepath
    data_dir = 'data'
    filename = 'cleared_checks.csv'
    path = File.join(data_dir, filename)    
  end
  
end

upload.haml

%form{:action=>"/upload", :method=>"post", :enctype=>"multipart/form-data"}
  %input{:type=>"file",:name=>"file"}
  %input{:type=>"submit",:value=>"Upload"}