PhantomJS

warmup-select-condition.js

var page = require('webpage').create();
var system = require('system');
if (system.args.length === 1) {
  console.log('Usage: phatomjs warmup-select-condition.js <some URL>');
  phantom.exit();
}
var address = system.args[1];
var lib = "//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js";

page.onConsoleMessage = function(msg) { console.log("console> " + msg); }

page.open(address, function(status) {
  if (status !== 'success') {
    console.log('FAIL to warm up the address');
  } else {

    var t = Date.now();
    setTimeout(function() {
      page.includeJs(lib, function() {
        console.log('----------------------------------------------------------------------');
        page.evaluate(function() {
          console.log("show_title: " + $("title").text());
          console.log("show_button: " + $("button").text());
          $("button").click();
        });
        console.log("time: " + (Date.now() - t) + "ms");
      });
    }, 0);

    setTimeout(function() {
      page.includeJs(lib, function() {
        console.log('----------------------------------------------------------------------');
        page.evaluate(function() {
          console.log("show_title: " + $("title").text());
          console.log("show_button: " + $("button").text());
          $("button").click();
        });
        console.log("time: " + (Date.now() - t) + "ms");
        phantom.exit();
      });
    }, 3000);

  }
});