disableautofill.js

disableautofill.js

The easiest solution for disabling Google Chrome auto-fill, auto-complete functions.

Concepts

This library does the following steps:

• Replace type="password" with type="text".
• Replace the text of password with asterisk symbols.
• Add an attribute autocomplete="off" on form.
• Randomize the attribute name in order to prevent Google Chrome to remember what you fill.

The library will restore the original password value when you submit the form and then replace the password value with asterisk symbols again.

The flowchart below shows the process of the library:

• Main: Acts as the entry point of the process, responsible for initializing other components.
• EventAdapter: Manages the addition and removal of DOM events.
• listen: Sets up listeners for specific form events, like keyboard inputs and form submissions.
• handle: Processes DOM elements (like password fields) based on triggered events.
• Randomizer: Performs randomization and restoration operations on form fields to manage password display.
• State: Maintains and updates form state, such as temporary and original password values.
• DOM Elements: Refers to the HTML elements (like input fields) that are directly manipulated.

Install

NPM

npm install disableautofill

or download the latest release.

Usage

new Disableautofill(form, options);

• form CSS selector or DOM element.
• options The options.

Options

option	default	type	note
fields	[]	array	The id or class of the fields (the input elements for filling password in the form). For example: ['.newpass', 'newpass2']
asterisk	●	string	Character use to hide the real password value.
callback	null	function	To validate form fields or something you can do.

Public Methods

destroy()

Removes all event listeners and restores the original form element. Please note that all events will be removed after calling this method.

init()

This method is called by default when you initialize the script. You can call this method to re-initialize the script after calling the destroy() method.

Examples

Assume that you have a form like this:

<form id="testForm" method="get" action="/">
  <div class="input-group">
    <label>Username</label>
    <input type="text" name="username" />
  </div>
  <div class="input-group">
    <label>Password</label>
    <input type="text" name="password" class="test-pass" />
  </div>
  <div class="input-group">
    <label>Confirm password</label>
    <input type="text" name="confirm_password" class="test-pass2" />
  </div>
  <div class="button-section">
    <button type="submit">Submit</button>
  </div>
</form>

In the Browser

UMD

Include the UMD package’s JavaScript file in your HTML document using a <script> tag.

<script src="./dist/disableautofill.js"></script>

And then, initialize the script in the next <script> section.

const checkForm = () => {
  form = document.getElementById('login-form');
  if (
    form.password.value === '' ||
    form.confirm_password.value === ''
  ) {
    alert('Cannot leave Password field blank.');
    form.password.focus();
    return false;
  }
  if (form.username.value === '') {
    alert('Cannot leave User Id field blank.');
    form.username.focus();
    return false;
  }
  return true;
};

new Disableautofill('#testForm', {
  'fields': [
    '.test-pass',
    '.test-pass2'
  ],
  'callback': function() {
    return checkForm();
  }
});

ES module

Or, you can use ES module.

<script type="module" src="./dist/disableautofill.es.js"></script>

Then, initialize the script in the subsequent <script> section. Since the module is asynchronous, it’s necessary to wait for the DOM to fully load before initializing the script. If you don’t, you might encounter a Disableautofill is undefined error.

const initializeDisableautofill = async () => {
  const checkForm = () => {
    form = document.getElementById('login-form');
    if (
      form.password.value === '' ||
      form.confirm_password.value === ''
    ) {
      alert('Cannot leave Password field blank.');
      form.password.focus();
      return false;
    }
    if (form.username.value === '') {
      alert('Cannot leave User Id field blank.');
      form.username.focus();
      return false;
    }
    return true;
  };

  new Disableautofill('#testForm', {
    'fields': [
      '.test-pass',
      '.test-pass2'
    ],
    'callback': function() {
      return checkForm();
    }
  });
};

window.addEventListener(
  'DOMContentLoaded',
  initializeDisableautofill
);

Node Environment

import Disableautofill from 'disableautofill';

const checkForm = () => {
  form = document.getElementById('login-form');
  if (
    form.password.value === '' ||
    form.confirm_password.value === ''
  ) {
    alert('Cannot leave Password field blank.');
    form.password.focus();
    return false;
  }
  if (form.username.value === '') {
    alert('Cannot leave User Id field blank.');
    form.username.focus();
    return false;
  }
  return true;
};

new Disableautofill('#testForm', {
  'fields': [
    '.test-pass',
    '.test-pass2'
  ],
  'callback': function() {
    return checkForm();
  }
});

Intergate with React

import React, { useEffect, useRef } from 'react';
import Disableautofill from 'disableautofill';

const LoginFormComponent = () => {
  const formRef = useRef(null);
  let mainInstance = null;

  useEffect(() => {
    if (formRef.current) {
      mainInstance = new Disableautofill(formRef.current, {
        fields: ['.test-pass', '.test-pass2'],
        callback: () => true
      });
    }

    return () => {
      if (mainInstance) {
        mainInstance.destroy();
      }
    };
  }, []);

  return (
    <form ref={formRef}>
      <div class="input-group">
        <label>Username</label>
        <input type="text" name="username" />
      </div>
      <div class="input-group">
        <label>Password</label>
        <input type="password" name="password" class="test-pass" />
      </div>
      <div class="input-group">
        <label>Confirm password</label>
        <input type="password" name="confirm_password" class="test-pass2" />
      </div>
      <div class="button-section">
        <button type="submit">Submit</button>
      </div>
    </form>
  );
};

export default LoginFormComponent;

This is the simple example of React. You may modify the code to fit your needs. See this example run in CodePen.

Intergrate with Vue

import { onMounted, onUnmounted, ref, createApp } from 'vue';
import Disableautofill from 'disableautofill';

const App = {
  setup() {
    const formRef = ref(null);
    let mainInstance = null;

    onMounted(() => {
      if (formRef.value) {
        mainInstance = new Disableautofill(formRef.value, {
          fields: ['.test-pass', '.test-pass2'],
          callback: () => true
        });
      }
    });

    onUnmounted(() => {
      if (mainInstance) {
        mainInstance.destroy();
      }
    });

    return { formRef };
  },
  template: `
    <form ref="formRef">
      <div class="input-group">
        <label for="username">Username</label>
        <input id="username" type="text" name="username" />
      </div>
      <div class="input-group">
        <label for="password">Password</label>
        <input id="password" type="password" name="password" class="test-pass" />
      </div>
      <div class="input-group">
        <label for="confirmPassword">Confirm Password</label>
        <input id="confirmPassword" type="password" name="confirm_password" class="test-pass2" />
      </div>
      <div class="button-section">
        <button type="submit">Submit</button>
      </div>
    </form>
  `
};

This is the simple example of Vue 3. You may modify the code to fit your needs. See this example run in CodePen.

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Development

npm run dev

Starts a Vite server with hot reload.

This page is the entry point of the development server. You can find it at http://localhost:9527/.

npm run lint

Executes linting by ESLint.

npm run test

Runs tests by Vitest.

npm run coverage

Runs coverage analysis by Vitest. Once you run this command, you can find the coverage report in the coverage directory.

http://localhost:9527/coverage/

You will see the coverage report like this:

Using Docker

If Docker is your preferred choice, here’s what you need to know.

Command	Description
npm run docker:image-build	Builds the Docker image.
npm run docker:image-remove	Removes the Docker image.
npm run docker:run	Runs the Docker image.
npm run docker:stop	Stops the Docker container.
npm run docker:remove	Stops and removes the Docker container.
npm run docker:test	Runs tests in the Docker container.
npm run docker:lint	Executes linting in the Docker container.
npm run docker:coverage	Runs coverage analysis in the Docker container.

Contributing

• Please create a branch off of the 4.x branch and submit your pull requests back to the 4.x branch.
• Run the commands npm run test and npm run lint before submitting your pull request. Ensure that all tests pass and there are no linting errors.

About

disableautofill.js is developed by Terry Lin. Thanks to CoLocal for sponsoring the development of this script. It is released under the MIT license, allowing for free and open use.