How to Set HTML5 Required Attribute in JavaScript?

html

required-attribute

form-validation

jquery

byAnton Shumikhin·Aug 20, 2024

Need to enforce form validation swiftly? Assign true to the required property of your input elements.

// Direct ID - no map needed!
document.getElementById('inputID').required = true;

// Using a CSS selector - fancy!
document.querySelector('input[type="text"]').required = true;

Expanding the horizons: alternate methods

Want to make your JavaScript more verbose? You can set required via setAttribute.

document.getElementById('inputID').setAttribute('required', '');

To remove the attribute, feel free to use removeAttribute but remember, setAttribute('required', 'false') won't babysit your form. Stick to removeAttribute.

The Boolean attribute conundrum

Delving into required, a Boolean attribute in HTML and Javascript. If it's there, we see it as true. Missing? Hello, false!

// Is it there or not
let isRequired = document.getElementById('inputID').hasAttribute('required');

// Alternatively, peek in property
isRequired = document.getElementById('inputID').required;

Simple life lesson: Setting setAttribute('required', '') is akin to element.required = true.

Time for multiple elements

Well, ever had to set the required for a party of elements? Gather them via querySelectorAll and use a loop to get the deed done.

// Iterate using forEach on nodes like confetti
document.querySelectorAll('.some-class').forEach((element) => {
  element.required = true; // You, you and you too!
});

JQuery joyride

Feeling fancy with your jQuery skills? Set required, and also remove it while you're at it.

// Set it like it's hot
$('input').attr('required', true);

// Or just get rid of it
$('input').removeAttr('required');

P.S. Don't forget to include the jQuery library. It's no magic wand!

Meddling with required attribute

Beware the nuances when setting and removing required. Ensuring robust experiences requires careful handling, not unlike handling chocolates on a sunny day.

// Validation can trip on this attribute
document.getElementById('inputID').required = true;

// This is not the droid you're looking for
document.getElementById('inputID').setAttribute('required', 'false');

// Use this, not magic
document.getElementById('inputID').required = false;

Syntax and method choice can make or break success. Especially when your solution spans multiple inputs or dynamic form generation.

Validation vortex and errors

Messing up with required is like messing with a beehive: validation errors can spring up entirely un-bee-lievable!

document.querySelector('form').addEventListener('submit', (event) => {
  let requiredInputs = this.querySelectorAll('[required]');
  for (let input of requiredInputs) {
    if (!input.value) {
      event.preventDefault();
      // Set better traps here!
    }
  }
});

Remember, required is a potent tool, and with great power comes great need for server-side checks too.

Consistency & maintainability

Consistency in your syntax is important for readability and maintainability, just like consistent coffee ☕ makes every morning bearable.

Stay consistent, not insistent

Pick one method and stick to it.

// Let's get a vote. Who prefers this?
inputs.forEach(input => input.required = true);

// Or run for president with this?
inputs.forEach(input => input.setAttribute('required', ''));

Wear the maintainer's cap

Aim for an easier tomorrow. Make a function and offload the required setting to it.

function makeRequired(selector) {
  document.querySelectorAll(selector).forEach((element) => {
    element.required = true;
  });
}

makeRequired('input[required]'); // Let the function take care of it