Semantic-UI Validations for Forms in Open Event Frontend

Open Event Frontend requires forms at several places like at the time of login, for creation of events, taking the details of the user, creating discount codes for tickets etc.. Validations for these forms is a must, like in the above picture, we can see that many fields like discount code, amount etc. have been left empty, these null values when stored at backend can induce errors.

Semantic-UI makes our life easier and provides us with it’s own validations. Its form validation behavior checks data against a set of criteria or rules before passing it along to the server.

Let’s now dive deeper into Semantic validations, we’ll take discount code form as our example. The discount code form has many input fields and we have put checks at all of them, these checks are called rules here. We’ll discuss all the rules used in this form one by one

  1. Empty

Here we check if the input box with the identifier discount_amount is empty or not, if it is empty, a prompt is shown with the given message.

         identifier : ‘discount_amount’,
         rules      : [
             type   : ’empty’,
             prompt : this.l10n.t(‘Please enter the discount amount’)

2. Checked
Here, we validate whether the checkbox is checked or not and if it is not, show corresponding message

rules      : [
     type   : ‘checked’,
     prompt : this.l10n.t(‘Please select the appropriate choices’)

3. RegExp

These checks are very important in input fields requiring passwords and codes, they specify the allowed input characters

rules      : [{
   type  : ‘regExp’,
   value : ‘^[a-zA-Z0-9_-]*$’

4.Custom rules

Many a times, we require some rules which are by default not given by semantic, here we can create custom rules.

Like here, we want to check whether the user has not set max value lower than min.

$.fn.form.settings.rules.checkMaxMin = () => {
     if (this.get(‘data.minQuantity’) > this.get(‘data.maxQuantity’)) {
       return false;
     return true;

Here, we are creating our own custom rule checkMaxMin which returns boolean value depending upon minQuantity and maxQuantity. Now, this can be directly used as a rule

identifier : ‘min_order’,
optional   : true,
rules      : [
  type   : ‘checkMaxMin’,
  prompt : this.l10n.t(‘Minimum value should not be greater than maximum’)

You can find the above code here

Additional Resources