Form Ninja

Form Ninja is a lightweight, easy-to-use JavaScript library for validating forms quickly and efficiently. It provides customizable validation methods to handle common form validation tasks without any complex configuration.

Features

• 🔥 Fast and Efficient: Validates forms instantly with minimal overhead.
• 🎯 Easy to Use: Simple API for validating forms, designed for quick integration.
• 🔌 Customizable: Add custom validation rules and error messages as needed.
• 🌐 Flexible: Works with any form structure and fields.
• 📦 Lightweight: No external dependencies or bloat.

Installation

To install via npm:

npm install form-ninja

Or using yarn:

yarn add form-ninja

Usage

Import the FormNinja and use it to validate your form fields.

import { FormNinja } from "form-ninja";

// Initialize the form validator with fields and rules
const form = new FormNinja("#user-form");

const USER_FORM = document.getElementById("user-form");

USER_FORM.addEventListener("submit", (e) => {
  form.trigger();

  if (form.isValid) {
    alert("Form submitted successfully");
  }
});

<form id="user-form">
  <div form-group="fullName">
    <label for="fullNameId">Enter your name</label>
    <input
      type="text"
      placeholder="Enter your full name"
      name="fullName"
      id="fullNameId"
      data-required
      data-required-message="Name can not be empty."
      data-control-name="fullName"
      data-pattern="^[a-zA-Z]+(?: [a-zA-Z]+)+$"
    />
    <p style="color: red" error-message="name"></p>
  </div>

  <button type="submit">Submit</button>
</form>

Custom Validation Rules

You can also add your own custom validation rules.

// Validates if the provided value is a valid date.
function isValidDate(value) {
  const date = new Date(value);

  const status = date instanceof Date && !isNaN(date);

  if (status) return;

  // If the date is invalid, return an error message and the invalid value
  return { message: "Please enter a valid date.", value };
}

const userForm = new FormNinja("#user-form", {
  validate: {
    // Add the isValidDate validator to the validation rules
    isValidDate,
  },
});

<div class="form-group">
  <label for="disclaimer">Enter Date of Birth</label>
  <input
    type="text"
    name="dateOfBirth"
    id="dateOfBirthId"
    data-control-name="dateOfBirth"
    data-required
    data-is-valid-date
  />
  <p style="color: red" error-message="dateOfBirth"></p>
</div>

Built-in Validation Rules

• required: Validates that a value is not empty.
• pattern: Validates that a value matches a specified regular expression pattern.
• min: Validates that a numeric value is greater than or equal to a specified minimum.
• max: Validates that a numeric value is less than or equal to a specified maximum.
• minLength: Validates that the length of a string value is at least a specified minimum length.
• maxLength: Validates that the length of a string value does not exceed a specified maximum length.
• custom: Add your custom validation logic.

API

FormNinja(query, config)

• query: The selector for the form element.
• config: Configuration object containing validation rules.

.reset()

• Resets all form fields to their initial values.

.resetField(control: string | Element)

• Resets the value of a single form field.
• control: The name of the form field or the field element to reset.

setValueConfig

The SetValueConfig type is an object used in the setValue method to determine whether to validate the field after setting its value.

export type SetValueConfig = {
  shouldValidate: boolean;
};

.setValue(name: string, value: any, config: SetValueConfig)

• Sets the value of a specific form field.
• name: The name of the form field to update.
• value: The new value for the form field.
• config: Optional configuration for setting the value. If shouldValidate is true, the field will be validated after setting the value.

.update(values: { [key: string]: any }, config: SetValueConfig)

• Updates multiple form fields with the provided values.
• values: Key-value pairs representing the form field names and their new values.
• config: Optional configuration object for updating the form (e.g., validation or UI options).

.getValues(controlName: string | null = null)

• Retrieves the current value(s) of the form.
• If a control name is provided, returns the value of that specific field; otherwise, returns an object containing all form field values.

.get isValid()

• Returns whether the form is valid.

.trigger(controlName: string | null = null)

• Triggers form validation.
• If a control name is provided, it validates only that specific field; otherwise, it validates the entire form.
• Returns a Promise that resolves or rejects based on validation results.

Example with HTML Form

<form id="user-form">
  <div form-group="fullName">
    <label for="fullNameId">Enter your name</label>
    <input
      type="text"
      placeholder="Enter your full name"
      name="fullName"
      id="fullNameId"
      data-required
      data-required-message="Name can not be empty."
      data-control-name="fullName"
      data-pattern="^[a-zA-Z]+(?: [a-zA-Z]+)+$"
    />
    <p style="color: red" error-message="name"></p>
  </div>

  <div>
    <label for="email">Enter your email</label>
    <input
      type="email"
      placeholder="Enter your email"
      name="email"
      id="email"
      data-required
      data-control-name="email"
      data-pattern="^[\w.-]+@[a-zA-Z]+\.[a-zA-Z]{2,}$"
    />
    <p style="color: red" error-message="email"></p>
  </div>

  <div>
    <label for="email">Enter your date of birth</label>
    <input
      type="text"
      placeholder="Enter your date of birth"
      name="dateOfBirth"
      id="dateOfBirthId"
      data-control-name="dateOfBirth"
      data-required
      data-is-valid-date
    />
    <p style="color: red" error-message="dateOfBirth"></p>
  </div>

  <div>
    <p>Please select the gender</p>
    <div>
      <label>
        Male
        <input
          type="radio"
          class="form-control"
          name="gender"
          data-control-name="gender"
          data-required
          value="male"
        />
      </label>

      <label>
        Female
        <input type="radio" class="form-control" name="gender" value="female" />
      </label>
    </div>

    <p style="color: red" error-message="gender"></p>
  </div>

  <div>
    <label for="disclaimer">Please select the disclaimer</label>
    <input
      type="checkbox"
      name="disclaimer"
      id="disclaimerId"
      data-control-name="disclaimer"
      data-required-true
    />

    <p style="color: red" error-message="disclaimer"></p>
  </div>

  <button type="submit">Submit</button>
</form>

<script>
  function isValidDate(value) {
    const date = new Date(value);

    const status = d instanceof Date && !isNaN(date);

    if (status) return;

    return { message: "Please enter valid date.", value };
  }

  const form = new FormNinja("#user-form", {
    validate: {
      isValidDate,
    },
  });

  const USER_FORM = document.getElementById("user-form");

  USER_FORM.addEventListener("submit", (e) => {
    form.trigger();

    if (form.isValid) {
      alert("Form submitted successfully!");
    } else {
      alert("Form has errors. Please correct them.");
    }
  });
</script>

Contributing

Contributions are welcome! If you find a bug or want to improve the library, feel free to submit a pull request or open an issue.

License

This project is licensed under the MIT License - see the LICENSE file for details.