How to refresh data on xbmcgui.WindowDialog?

Code:
# -*- coding: utf-8 -*-

import xbmc, xbmcplugin, xbmcaddon, xbmcgui

import re

import urllib2

from datetime import datetime

import time, locale, pytz

import platform,os

import json, threading



locale.setlocale(locale.LC_TIME,'')

'tr_TR.UTF-8'



sysarg=str(sys.argv[1])

ADDON_ID='script.kralex.foreign'

addon = xbmcaddon.Addon(id=ADDON_ID)





def cek(link):

   req = urllib2.Request(link)

   req.add_header('User-Agent',

                  'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.99 Safari/537.36')

   yanit = urllib2.urlopen(req)

   sonuc = json.load(yanit)

   yanit.close()



   return sonuc



def convert_datetime_timezone(dt, tz1, tz2):

   tz1 = pytz.timezone(tz1)

   tz2 = pytz.timezone(tz2)

   try:

       dt = datetime.strptime(dt,"%Y-%m-%dT%H:%M:%SZ")

   except:

       dt = datetime.fromtimestamp(time.mktime(time.strptime(dt, "%Y-%m-%dT%H:%M:%SZ")))

   dt = tz1.localize(dt)

   dt = dt.astimezone(tz2)

   dt = dt.strftime("%c")

   return dt



url = 'https://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22USDTRY%22,%20%22EURTRY%22)&env=store://datatables.org/alltableswithkeys&format=json'





class MyAddon(xbmcgui.WindowDialog):

   def __init__(self):

       veri = cek(url)

       tarih = veri['query']['created']

       tarih = convert_datetime_timezone(tarih, "UTC", "Europe/Istanbul")



       dolar = []

       euro = []



       for x in veri['query']['results']['rate']:

           if x['id'] == 'USDTRY':

               dolar = x['Rate']

           if x['id'] == 'EURTRY':

               euro = x['Rate']



       self.addControl(xbmcgui.ControlImage(800,20, 500, 100, ""))

       self.list = xbmcgui.ControlList(810, 20, 500, 110, 'font12', '0xFFFFFFFF')

       self.addControl(self.list)



       self.list.addItem('Dolar:               ' + dolar +' TL\nGuncelleme:    ' + tarih)



       self.setFocus(self.list)

       xbmc.executebuiltin('Dialog.Close(10138)')



if __name__ == '__main__':

   myaddon = MyAddon()

   myaddon.doModal()

   del myaddon