reformer

Self-contained, self-rendering, self-validating forms that can only output valid data.

Step #1: Define your fields, with as many tests as you want for each field:

var f = new Reformer({
  fields: [
    {
      name: 'first_name',
      label: 'First Name',
      placeholder: 'Something',
      required: true
    },
    {
      name: 'last_name',
      label: 'Last Name',
      tests: [
        {
          test: function (val) {
            return false;
          },
          message: 'something will always go wrong'
        },
        {
          test: function (val) {
            return val && val.toString().length > 2;
          },
          message: 'Must be at least three characters.'
        }
      ],
      required: true
    }
  ],
  submit: function (vals) {
    console.log(vals);
  },
  error: function (vals) {
    console.log('error', vals);
  }
});

Step #2: Render it once. It handles itself after that:

document.addEventListener('DOMContentLoaded', function () {
  // render our form from about, just tell it where.
  f.render({
    formEl: document.getElementById('myform'),
    fieldContainer: document.getElementById('fieldContainer'),
  });
});

Reformer will handle form submit, and call your callback if everything's happy.

Bonus Step #3: Asynchronous validation

You know how you've always got that one field that needs to be checked via ajax. It's a pain. Because most of your tests are simple regexes that can be run synchronously except for this one stupid ajax call to check if a username is available. So, just do this:

// your field definition
{
  name: 'email',
  label: 'Email',
  tests: [
    // BAM! add the `async` flag and your test will receive a third argument. A callback.
    {
      async: true, 
      test: function (email, formInstance, cb) {
        $.get('/email-is-avail?val=' + email, function (data) {
          cb(data === '1');
        });
      },
      message: 'This email is already in use.'
    },
    // You can have simple synchronous tests alongside as well.
    // and it still Just Works™
    {
      test: _.isEmail,
      message: 'This doesn\'t seem like a real email address'
    }
  ],
  required: true
}

It's simple, but that's all for now. Because it works for what I need for this particular app. Contributions welcomed.

Cheers,

- @HenrikJoreteg

Gotchas

• Still needs a bit more work/polish/testing.
• Requires IE8 or newer because I didn't want jQuery as a dependency.

License

MIT