Add specific validation rules for a custom field

I would like to add a custom date field on the checkout page. I need to do some custom validation on this date field. Customers should select a date in the future (which is already possible) but some dates are not allowed. Is it possible to add some specific validation code (even if it means that this code is lost when upgrading hikashop)

Thanks.

Just another remark about the existing validation on 'future' or 'past' dates. When selecting a date from the date control, the validation is done correctly but when a user types a date without using the date control, no validation is done. Is that a (known) bug or am I doing something wrong ?

I even have the same issue when entering a date manually in the same format as it is displayed when selecting a date from the control. Would it be possible that I disable the textfield so that users should use the control to select a valid date ?

Thanks a lot, the validation on the date field is also executed now when entering a date manually. There is only one issue when people entering dates in an incorrect format (not yyyy-mm-dd). In that case, the validation does not work properly but I can add an additional test in the javascript to check the format with a regular expression.

In which version will this bugfix be included and when will it be released. I just started with the Hikashop starter edition and have done an evaluation of the functionality. I'm happy with it and I will sell the business edition in the coming days.

When adding the code for checking the date format, I always get the following error :
Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING in .../public_html/administrator/components/com_hikashop/classes/field.php on line 1219

For the rest everything works fine in Firefox and Google Chrome but I tested also on Internet Explorer 7. In this browser, the check on future or past dates doesn't work at all. When selecting a date in the control or typing a date manually, an 'Error on page' occurs.

I tried again and now after my upgrade to the Business edition,I don't have the error anymore. It was probably due to a mistake in the translation file. So, now I don't have the error anymore but, I never get the message 'Incorrect date format', even when I type a date in a format like 15/12/2011. When I try it with the regular expression it works (except in Internet Explorer).

Besides, I also have a question about the checkout process. In my current checkout process, I see the different parts (as defined in the configuration) and everything works fine but at the end of the checkout process, users have to click the 'next' button. After clicking 'next', a page is displayed that tells them that the order was already submitted. I wonder if there is a possibility to add some confirmation page in between so that users really now that they will already submit the order when pressing the 'next' button. Another option would be that I can change the 'Next' button on the bottom of the checkout page into a button with label 'Submit order'. In that case, no intermediate confirmation is necessary.

Thanks for the information.

The code that you have sent works fine in Google Chrome as well as in Firefox but the date control doesn't close anymore after selecting the date. When clicking the x button, nothing happens. It's not blocking as it's still possible to click the next button but it's not optimal and in Internet Explorer, the control doesn't work at all. Here, the user is really blocked because the 'incorrect_date_format' error pops up every time you select a date and the close button doesn't work. Because of this, I'm not sure if this code should be implemented as a global solution in a next release.