simple javascript keystroke count

Question

I'm developing an online study/survey where I need to count the number of keystrokes that a participant makes. I am asking them to type lrlrlrlrlrlrl... in a text field to simulate walking. Turns out many of the participants (as evidenced by the time spent on the task) are copying and pasting.

I need something that will count keystrokes so I can identify participants who completed the task as requested. The study is programmed in Coldfusion and I was thinking about some sort of javascript/onkeydown/hidden file field combination, but I am not really a programmer.

Any help would be appreciated. Thanks.

You could use jquery to register on keyup events and count how many time this event was raised, so you would know how many keys have been pressed. — mas-designs
– mas-designs, Commented Aug 24, 2012 at 14:25

Shmiddty · Accepted Answer · 2012-08-24 15:14:44Z

3

http://jsfiddle.net/kBJGM/

HTML:

<input type="text" class="nopaste"/>
<input type="text" id="countstroke"/>
<span id="count"></span>

Javascript:

var strokeCount = 0;

$(function(){

    $(".nopaste").bind("copy paste", function(e){
        e.preventDefault();
    });

    $("#countstroke").keyup(function(){
        $("#count").text("Count: " + (++strokeCount));
    });
});

If you want to take it a step further, you can enforce that only the L and R keys are registered (http://jsfiddle.net/kBJGM/5/):

$("#restrictivecount").keypress(function(e){
    var seq = rstrokeCount % 2;
    var allow = true;
    switch(e.keyCode){
        case 76:
        case 108: // L or l
            if (seq == 1) allow = false;
        break;
        case 82:
        case 114: // R or r
            if (seq == 0) allow = false;
        break;               
        default:
            allow = false;
        break;               
    }

    if (allow)
        $("#rcount").text("Count: " + (++rstrokeCount));
    else
        e.preventDefault();
});

edited Aug 24, 2012 at 15:14

answered Aug 24, 2012 at 14:35

Shmiddty

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1 Comment

Shmiddty Over a year ago

This is two possible solutions to your problem. The first one prevents copy/paste. The second answer counts keystrokes, but they can still copy/paste.

mas-designs · Accepted Answer · 2012-08-24 14:30:27Z

0

var keyPressCount = 0;

$(document).on("keydown",function(){
   keyPressCount++;
});

check out this fiddle

answered Aug 24, 2012 at 14:30

mas-designs

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1 Comment

user1622853 Over a year ago

Thanks! Another stupid question, but how do I get this into a form variable that I can pass to the database?

Martin Thoma · Accepted Answer · 2012-08-25 09:01:59Z

-1

count=0;

$(document).bind('keydown', function(event){
    var keyCode = event.keyCode;
    switch(keyCode){
        case 39:
            alert('Right arrow was pressed');
            count++;
            break;
        case 37:
            alert('Left arrow was pressed');
            count++;
            break;
    }
});

You must have jQuery library to make this work.

edited Aug 25, 2012 at 9:01

Martin Thoma

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answered Aug 24, 2012 at 14:38

Yauhen Vasileusky

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2 Comments

Yauhen Vasileusky Over a year ago

bind is a function from jQuery

mas-designs Over a year ago

Yeah it is, its a method or function and not as you wrote a jQuery Plugin.

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