custom validation on option text field

Hi, i want to know that is there any method so that i can apply custom validation on the "options" text field . i want to collect IMEI number of mobile .i know the field option but it shows in the billing section, or how can i add my custom validation in back-end, which file i should use so that i can get the field class or add custom class for validation ...!!!! :dry: i want to use option text field on product page .

Hello Hassan,

Currently, EShop does not support the IMEI number validation rule foe custom field. To have it, you should make the customization to the custom field validation of EShop.

Sincerely, Giang

how can i customize the custom field. can you give me some advice or guide me to the exact file so that i can make the customization ....!!!! it will be very helpful....!!!

Hi Hassan,
It's hard to guide you what you must do exactly here. However, you can check how I coded for default custom fields and default rules to understand how it works, then add the code by your self.
Sincerely, Giang