AB-formValidation

AB-formValidation is a small, detpendency free, vanilla JavaScript component that validate fields and forms following the native HTML5 Form API. It's used (a customized version) on the French website of ENGIE.

It's damn small: about 1800 bytes (uglyfied and GZipped).

Have a look at the CodePen demonstration.

Install

Install with npm:

npm install --save ab-formvalidation

Install with yarn:

yarn add ab-formvalidation

You can then import it in your JS bundle (webpack, ES6, browserify…):

import abFormValidation from 'ab-formvalidation';

Or loading the .js file right before </body> if you are not using a builder.

Setting up a Form

• data-ab-form-validation attribute must be placed on your <form> element.

• data-ab-form-validation-submit must be placed on the submit <button type="submit"> or <input type="submit"> element.

• run inside your JavaScript: window.abFormValidation();. If your form is injected with XMLHttpRequest, you can run the same function again in the callback.

HTML

<form data-ab-form-validation>
  …

  <button type="submit" data-ab-form-validation-submit>Send</button>
</form>

JavaScript

Default settings for checked fields can be set when initializing the script:

window.abFormValidation({
  "classValid":        "is-valid",
  "classInvalid":      "isnt-valid",
  "classBtnDisabled":  "is-disabled",
  "typing":            false,
  "submitDisabled":    true,
  "validations": {
    "badInput":        "error: badInput",
    "patternMismatch": "error: patternMismatch",
    "rangeOverflow":   "error: rangeOverflow",
    "rangeUnderflow":  "error: rangeUnderflow",
    "stepMismatch":    "error: stepMismatch",
    "tooLong":         "error: tooLong",
    "tooShort":        "error: tooShort",
    "typeMismatch":    "error: typeMismatch",
    "valueMissing":    "error: valueMissing"
  }
});

Options explained

• Personnalize dynamic classes for your styling:

  "classValid":       "is-valid",
  "classInvalid":     "isnt-valid",
  "classBtnDisabled": "is-disabled",

• Choose realtime field validation (while typing) or not (onChange):

  "typing": false,

• DBy default, submit button will be disabled. If you want to validate fields on submit, change setting to false:

  "submitDisabled": true,

• Personalize error messages triggered by HTML5 Form API:

  "validations": {
    "badInput":        "error: badInput",
    "patternMismatch": "error: patternMismatch",
    "rangeOverflow":   "error: rangeOverflow",
    "rangeUnderflow":  "error: rangeUnderflow",
    "stepMismatch":    "error: stepMismatch",
    "tooLong":         "error: tooLong",
    "tooShort":        "error: tooShort",
    "typeMismatch":    "error: typeMismatch",
    "valueMissing":    "error: valueMissing"
  }

More interesting: define settings for a field

Only fields with data-ab-field-validation will be evaluated. Set specific settings in that attribute if needed.

<xxx data-ab-field-validation='{
  "typing": false,
  "validations": {
    "badInput":        "error: badInput",
    "patternMismatch": "error: patternMismatch",
    "rangeOverflow":   "error: rangeOverflow",
    "rangeUnderflow":  "error: rangeUnderflow",
    "stepMismatch":    "error: stepMismatch",
    "tooLong":         "error: tooLong",
    "tooShort":        "error: tooShort",
    "typeMismatch":    "error: typeMismatch",
    "valueMissing":    "error: valueMissing"
  }
}'>

Events and public access

• FORM: an event is triggered on each form submit Real form submition (AJAX or not) is to be done on your side. To do so, listen to this specific event:

  document.addEventListener('submit.ab-formvalidation', function(e) {
    // e.detail.form:  submited form
    // e.detail.valid: form validity (boolean)
  
    if (e.detail.valid) {
      e.detail.form.submit(); // or call your own AJAX function
    }
  });

• FIELD: check a specific field validity from your scripts

  // select the parent with the data-ab-field-validation attribute
  var myField = document.querySelector('…');
  
  myField.abFieldValidation.checkValidity();
  // return true or false

• FIELD: set custom error status (after an AJAX validation for ex.)

  // select the parent with the data-ab-field-validation attribute
  var myField = document.querySelector('…');
  
  myField.abFieldValidation.setCustomError('My custom error message');

• FIELD: an event is triggered on each field validation

  document.addEventListener('checked.ab-fieldvalidation', function(e) {
    // e.detail.field: checked field
    // e.detail.valid: field validity (boolean)
  });