Javascript code

Qualtrics.SurveyEngine.addOnload(function()
{
	/*Place your JavaScript here to run when the page loads*/
	// standard version of the BART

$(document).ready(function() { 

  // initialize values
  var round = 0;
  var start_size = 150; // start value of widht & height of the image; must correspond to the value that is specified for the #ballon id in style.css
  var increase = 2; // number of pixels by which balloon is increased each pump
  var size; // start_size incremented by 'increase'
  var pumps; 
  var thanks;
  var maximal_pumps=32;
  var pumpmeup; // number pumps in a given round; is updated each round
  var number_pumps = []; // arrays for saving number of pumps
  var total = 0; // money that has been earned in total
  var explosion; // will an explosion occur? 1 = yes, 0 = no
  var last_win = 0; // initialize variable that contains the win of the previous round
  var present_win = 0; //initialize variable of win in present around
  var rounds_played = 10;
  var exploded = []; // array for saving whether ballon has exploded
  //var explode_array =  [15, 9,  16, 26, 22,  8, 27,  17, 23,  29,];
  var BurstProb; //Random variable that determines whether balloon burst
						
  // initialize language
  var label_press = 'Inflate balloon';
  var label_collect = 'Collect';
  var label_balance = 'Total credit:';
  var label_last = 'Win last round:';
  var label_currency = ' points';
  var label_times=' times';
  var label_header = 'Balloon Game Round ';
  var label_gonext1 = 'Start next round';
  var label_gonext2 = 'end game';
  var msg_explosion1 = '<p> The balloon is exploded after puming ';
  var msg_explosion2 = ' times.</p> <p>Once inflated burst, you did not make any money this round </p>';
  var label_present_time = 'Pumping times:';
  var label_present_value = 'Earn this round:';		

  
  var msg_collect1 = '<p> The balloon did not burst! </ p> <p> You deserve this round ';
  var msg_collect2 = ' Points. </ p> <p> The money earned is safe in the bank.</p>';

  var msg_end1 = '<p> This completes this part of the study. You are in the balloon game ';
  var msg_end2 = ' points made profit. </ p> <p> Click <i> Next </ i> to continue the study. </ p>';
  
  
  // initialize labels 
  $('#press').html(label_press); 
  $('#collect').html(label_collect);
  $('#total_term').html(label_balance);
  $('#total_value').html(total+label_currency);
  $('#last_term').html(label_last);
  $('#last_value').html(last_win+label_currency);
  $('#present_value_term').html(label_present_value);
  $('#present_times_term').html(label_present_time);
  $('#present_value').html(present_win+label_currency);
  $('#present_times').html(pumpmeup+label_times);
  $('#outcomes').html(number_pumps);
  
  // below: create functions that define game functionality
  
  // what happens when a new round starts
  var new_round = function() {
    //console.log(number_pumps);
    //console.log(exploded);
    $('#gonext').hide();
    $('#message').hide();  
    $('#collect').show();
    $('#press').show();
	$('#present_times').show();
	$('#present_value').show();
    round += 1;
    size = start_size;
    pumps = 0;
	present_win =0;
	show_present();
	show_present_earns();
    $('#ballon').width(size); 
    $('#ballon').height(size);
    $('#ballon').show();
    $('#round').html('<h2>'+label_header+round+'<h2>');
	$('#present_round').show();
	$('#outcomes').hide();
	$('#NextButton').hide();
  };
  
  // what happens when the game ends
  var end_game = function() {
    $('#total').remove();
    $('#collect').remove();
    $('#ballon').remove();
    $('#press').remove();
    $('#gonext').remove();
    $('#round').remove();
    $('#last_round').remove();
    $('#goOn').show();
    $('#message').html(msg_end1+total+msg_end2).show();
	$('#outcomes').show();
	$('#NextButton').show();
	Qualtrics.SurveyEngine.setEmbeddedData('number_pumps',number_pumps);
        Qualtrics.SurveyEngine.setEmbeddedData('exploded',exploded);
	Qualtrics.SurveyEngine.setEmbeddedData('total_win',total);

	
  };
  
  // message shown if balloon explodes
  var explosion_message = function() {
    $('#collect').hide();
    $('#press').hide();
    $('#message').html(msg_explosion1+pumpmeup+msg_explosion2).show();
  };
  
  // message shown if balloon does not explode
  var collected_message = function() {
    $('#collect').hide();
    $('#press').hide();    
    $('#message').html(msg_collect1+present_win+msg_collect2).show();
  };  

  // animate explosion using $ UI explosion
  var balloon_explode = function() {
    $('#ballon').hide( "explode", {pieces: 100}, 800 );
    document.getElementById('explosion_sound').play();
  };  
  
  // show button that starts next round
  var gonext_message = function() {
    $('#ballon').hide();
    if (round < rounds_played) {
      $('#gonext').html(label_gonext1).show();
    }
    else {
      $('#gonext').html(label_gonext2).show();
    }
  };

  // add money to bank
  var increase_value = function() {
    $('#total_value').html(total+label_currency);
  };
  
  var show_last = function() {
    $('#last_value').html(last_win+label_currency);
  };
  var show_present=function(){
	$('#present_times').html(pumps+label_times)
  }
  var show_present_earns=function(){
	$('#present_value').html(present_win+label_currency)
  }
   var show_array=function(){
	   $('#pump_array').html(number_pumps)
   }
  
  // button functionalities
  
  // pump button functionality -> 'pressure' in slider bar increases
  $('#press').click(function() {
     BurstProb = Math.random(); //generate random number between 0 and 1
    if (pumps >= 0 && pumps < maximal_pumps) { // interacts with the collect function, which sets pumps to -1, making the button temporarily unclickable
      explosion = 0; // is set to one if pumping goes beyond explosion point; see below
      pumps += 1;
	  present_win +=0.25;
	  //Burst probabilty is 1 / (maximal_pumps-pumps+1) as in Read et al. in 2002, so probability to burst increase with number of pumps, pumping becomes more risky
	  //Because BurstProb is random number between 0 and 1, the propbability that BurstProb > 1/(maximal_pumps-pumps+1) is equal to 1 - 1/(maximal_pumps-pumps+1)
	  //and the probability that BurstProb < 1/(maximal_pumps-pumps+1) is equal to 1/(maximal_pumps-pumps+1)
	  //In other words, the ballon will burst with probability 1/(maximal_pumps-pumps+1), and will not burst with probability 1-1/(maximal_pumps-pumps+1)
      if (BurstProb > 1/(maximal_pumps-pumps+1) {
	size +=increase;
	$('#ballon').width(size); 
        $('#ballon').height(size);
		show_present();
		show_present_earns();
      }
      else {
	last_win = 0;
	pumpmeup = pumps;
	pumps = -1; // makes pumping button unclickable until new round starts
	explosion = 1; // save that balloon has exploded this round
	balloon_explode();
	exploded.push(explosion); // save whether balloon has exploded or not
	number_pumps.push(pumpmeup); // save number of pumps
	 $('#ballon').hide();
	$('#present_round').hide();
    setTimeout(explosion_message, 1200);
	setTimeout(gonext_message, 1200);
	setTimeout(show_last, 1200);
      }
    }
  });
  
  
  // collect button: release pressure and hope for money
  $('#collect').click(function() {
      if (pumps === 0) {
	alert('you can only collect the money once you click "给气球充气”。');
      }
      else if (pumps > 0) { // only works after at least one pump has been made
	exploded.push(explosion); // save whether balloon has exploded or not
	document.getElementById('tada_sound').play();
	number_pumps.push(pumps); // save number of pumps
	pumpmeup = pumps;
	pumps = -1; // makes pumping button unclickable until new round starts
	$('#ballon').hide();
	$('#present_round').hide();
	collected_message();
	gonext_message();
	total += present_win;
	last_win = present_win;
	increase_value();
	show_last();
      }
  });
  
  // click this button to start the next round (or end game when all rounds are played)
  $('#gonext').click(function() {
    if (round < rounds_played) {
      new_round();
    }
    else {
      end_game();
    }
  });  


  // start the game!
  new_round();
  
});

});

Qualtrics.SurveyEngine.addOnReady(function()
{
	/*Place your JavaScript here to run when the page is fully displayed*/

});

Qualtrics.SurveyEngine.addOnUnload(function()
{
	/*Place your JavaScript here to run when the page is unloaded*/

});