I'm trying to use boots-faces for the first time and was looking for some validations at the client side like minimum length, maximum length or exact length.
I was able to find maxLength but I'm struggling to find how to do other length validations. Kindly suggest.
We didn't implement it yet. Please open a feature request at https://github.com/TheCoder4eu/BootsFaces-OSP/issues.
By the way, how do you want the validation messages to be displayed? Currently, maxLength is simply added to the HTML sourcecode. So it's up to the browser to interpret it. In the case of maxLength, that's easy because it suffices to stop accepting input after reaching the maximum length.
minLength, exactLength, and pattern are different. They have to be able to show regular error messages. That amounts to finding the corresponding h:message(s), b:message(s), or p:message(s) tag and populating it with error messages on the client side.
The PrimeFaces team implemented the feature. That was a lot of work, and my perception is that few people miss it. I'd be happy to be proven wrong because the BootsFaces story is all about shifting logic to the client.
In the meantime, just follow the suggestion of @Tiny above and BalusC and use the AJAX engine:
<b:input value="...">
<f:validateLength minimum="..." maximum="..." />
<f:validateRegex pattern="^$|^[A-Za-z-_./\s]{2,50}$" />
</b:input>
