Form validation with numeric rules

Question

I'm trying to validate input field in Magento 2. I have added js to same page, so validation like this data-validate="{required:true, 'validate-email':true}" works.

But how to validate min_text_length or max-words or something that requires number, not just true or false?

This is how I tried but it does not work.

<input value="Name" name="first_name" id="first_name_field" class="input-text" data-validate="{required:true, 'min_text_length':'20'}" type="text">

Answer 1

You can try the below code.

Only added 'validate-length':true in the tag.

<input value="Name" name="first_name" id="first_name_field" class="input-text" data-validate="{required:true,'validate-length':true, 'min_text_length':'20'}" type="text">

OR

<input value="Name" name="first_name" id="first_name_field" data-validate="{required:true, 'validate-length':true}" class="validate-length minimum-length-[0-9]+$ maximum-length-[0-9]+$ input-text" type="text" />

Answer 2

Turns out it is a bug of Magento 2. I'm currently on Magento CE 2.1.7 and this bug is not fixed, and the solution is exactly in this discussion:

Magento 2 minimum length validation is not working for text field