Show HN: Form-validation.js – JavaScript form validation library

Sorry but that example code looks confusing as hell. If I saw that code without any context, I really wouldn't be able to tell you what it's doing.

Seriously, this is why I hate modern web development. Absolutely everything seems stuffed full of incredibly over-the-top complexity.

Libraries like jQuery get a lot of hate because they're not trendy or supposedly impact performance too much, but unless you're serving thousands of visitors simultaneously you really should care more about code readability and maintainability than any of that.

At least with something like jQuery validation you can actually understand what the code is doing:

  $("#myform").validate({
    rules: {
      name: "required",
      email: {
        required: true,
        email: true
      }
    },
    messages: {
      name: "Please specify your name",
      email: {
        required: "We need your email address to contact you",
        email: "Your email address must be in the format of name@domain.com"
      }
    }
  });

I've been pretty happy with Formik (https://formik.org/docs/overview) for the past few years. Any comparison to this library?

I prefer standards.

For example json-editor:

https://github.com/json-editor/json-editor

It uses json schema validators that have big toolset available.

The link for live example does not check for the rule between 3-5 characters for activity name. The rule.js needs to return true for minLength. Just posted it here instead of creating issue, hope it is fine.

Wow yet another validation library, this one is special because it doesnt care about typescript.

Seriously a big part of the problem is to infer type information as you write validators. Anyone can just invent a dsl for type schema. Npm already has heap of these. If we want the schema approach we' probably go with something json-schema based.

Have a look at io-ts and runtypes to see what what a modern js validator should look like (again has something to do with typescript)

It is nice that this has no dependencies, but this strikes me as adding a massive amount of boilerplate than what would be normally necessary due to the flexibility.

What problem is this resolving? A short intro on the repo might help. Maybe I'm missing the point but I implement validation using standard browser APIs semi-regularly. It used to be painful, these days it is incredibly straightforward. The only place I would potentially consider a validation library is as a side-loaded polyfill for IE. Please explain?

If you’re looking for something with less boilerplate but still extensive extensibility, check out https://strickland.io. It also has no dependencies and is pure JavaScript.

If you're looking for something a bit more minimal, check out Pristine: http://pristine.js.org/