Captcha v2.0 beta

[Dee]

23/08/2010:
Added two error message properties - ErrorTooFast and ErrorTooSlow, for too fast and too slow input.
Added one method - CheckCaptcha. It works exactly like ValidateCaptcha, but returns boolean (IsValid). It's a shortcut to calling ValidateCaptcha and then checking for IsValid property.
Assembly is strong named now.


22/03/2010:
New function: arithmetic captcha. The difference with ordinary captcha is that the answer is not what is written in captcha itself, but the result of the arithmetic function presented in the picture. This will fight bots much better, but may cause some brain damage to your users  

In attached image you can see such image. Such captcha will be validated if user will enter "109" in the input field.

There are two new properties for Captcha, called Arithmetic and ArithmeticFunction. The first is false by default, and the second is "Addition" by default.

Arithmetic="true" ArithmeticFunction="Addition"

Please note, that this is a beta version of the component. It should work fine if used without arithmetic function, but you should test it before use if you are using any new functionality! Although it is presumably error-free.

The non-beta edition of this component will be released after implementing some new planned functionality.

UPDATE 23/08/2010: The file in this message contains the latest release of beta (scroll down for more details)

[raskals]

Downloaded and in use, only issue is that output doesn't produce valid xhtml. Try and validate a page with the control on and you will see what I mean.

[mtr]

Hi,
just
1. remove "border" attribute from output and leave it to end user stylesheets
2. provide end tag "/>" instead of existing ">" for "<image (...)" output tag.
we are in xhtml1.1 age (in VS2005)

Your Captcha control is really useful. If you fix these two flaws, it will be a masterpiece.
:)

I am looking forward to seeing quick fix.
Mike

[Dee]

The border tag removed. A new property was added to control, called ImageTag, with default value of "border = "0"". You can assign whatever new value to that property and it will be added to the IMG tag properties.

IMG tag is now closed properly with />

Binaries are available from the first message (.zip file contains comment with date and version of that particular release).

 

[mtr]

Ok now:
<div class='captchaControl' style='background-color:White;' /><img src="CaptchaImage.axd?guid=0648cfe8-99dc-4d98-9046-d79a60d847b8" border="0" alt="Captcha" width="150" height="31" /></div>

Look above and remove ending /> tag from <div>

In other words:
<div class='captchaControl' style='background-color:White;' />
change to
<div class='captchaControl' style='background-color:White;' >


We are much closer than before to final successful validation. :-]

[Dee]

 

Done!

Update: will check it again in a few hours.

[mtr]

The latest flaw is unfixed. :-(

[Dee]

Well, now it definitely is 

[mtr]

Yes, it is. I confirm. :-)
 

[akasnowboard]

Is there no way to get the Captcha answer (either "XVDFG" or the answer to the Arithmetic) BEFORE the page renders?  I am displaying the CAPTCHA but then submitting the form to a web service.  Obviously, the web service can't check the "Valid" property of the control.  But, I can MD5 the answer before the page renders, include it in the form as a hidden field, then when the user submits the form, I'll pass along the CAPTCHA along with the MD5 hash to the web service, where I can determine if it was valid or not.

Thanks

[Dee]

Take a look at another topic here. We are currently implementing the third caching method, so the answer will actually be given to the client in hashed form, instead of being stored server side. I guess it answers your question.

[nickshel]

Hi, great control, but I found a MAJOR problem for my implementation, which needs to support multiple languages... Validation Error Messages are HARDCODED!!!  There are a number of hardcoded error messages in the ValidateCaptcha function based on what I can see in Reflector...  These errors should just be implemented as Properties on the control and defaulted to whatever strings, but still allow for them to be changed.  Given that you use string concatenation, I'd also go for String.Format so that you can just enter a single line of text into the property.  Seems like you need 4 additional properties for the error messages.

Another thing... Rather than requiring for code to be added into the page to perform the validation, why not just add a ControlToValidate property to the Captcha Control, which is already implementing the IValidator interface and get the control to work like any other standard validator... You could also perform the validation in your code to ensure that the ControlToValidate is a Textbox control.

Please try to get these issues fixed as soon as possible as it's a great control.

PS. I also think that adding the math stuff is just overkill... Why get users to do more mental work than required and unnecessarily complicate the code, thus making it more difficult to maintain and more error prone?  IMHO simplicity is the key and as long as it's XHTML compiant, etc, etc the basic CAPTCHA is all that's needed.

[nickshel]

Also, might want to use Red Gate's .NET Reflector to have a look at how BaseValidator class has been implemented and take a fair bit of code from that.  It would definately be best to have this control work like every other Validator control and have a ControlToValidate property set to the text field.

[Dee]

Do not post binaries here.

If you need a feature implemented, submit a poll. If others will agree, it will be implemented.

[nickshel]

OK, no probs, will keep in mind for the future... Can you please fix the globalization issue though as it's not a feature request but more of a bug as something that shouldn't be hardcoded has been hardcoded.