Adding custom global javascript validation

Question

I have done some digging in internet but I haven't found any confirmed solution. What is the way to add custom js validation rule, that can be used globally as for example frontend_class for attributes or validation classes for form's inputs? It would be the best if I could store it in one of my modules.

By the way, for version 2.05 is there any class validating by min or max lenght of string/number of characters? The ones I have found in net don't work (seems to me they are outdated).

Answer 1

Assuming you add a validation class via the frontend_class let's say "validate-custom-class" you'll need to use the following JS to add a custom validation based on a this class:

require([
 'jquery',
 'jquery/ui',
 'jquery/validate',
 'mage/translate'
], function($){ 
 $.validator.addMethod(
 'validate-custom-class', function (value) { 
 // Add your validation logic here
 // Needs to return true if validation pass
 // Or false if validation fails
 }, $.mage.__('Field is not valid'));
});

• Bartosz Kubicki: ok and where should put this code? JS file, but where is good place for this? If I want to use it in some form I also add only validate-custom-class in the way it is done with other validation classes?
• Raphael at Digital Pianism: Yes same way as it's done with other validation classes. You place the direct JS in a <script> tag below your form or you can put this code in a JS file and include it in your page head tag it's up to you
• Bartosz Kubicki: is there any recommended way to add it globally, so any of my form or setup script could use this custom one?
• Raphael at Digital Pianism: @lord_of_strings well if you add that JS on every page you'll be able to use it globally ;)
• Raphael at Digital Pianism: @lord_of_strings you can follow this link: alanstorm.com/magento_2_javascript_css_layout_woes or look for "add JS globally Magento 2" on StackExchange