Validating a Form with Parsley.js

JavascriptProgramming ScriptsWeb DevelopmentFront End Technology

In this tutorial, we will show how you can use Parsley.js, which is a JavaScript library that is mainly used to validate forms. Parsley helps in validating the forms in a very subtle and easy manner, and it is one of the widely used form validation libraries out there.

Features of Parsley.js

There are plenty of reasons why Parsley is a good choice for validating your JavaScript forms. Some of them are mentioned below.

  • Intuitive DOM API − The DOM API allows you to use simple English inside your HTML tags, and Parsley will do the rest. There's no need for you to write a single JavaScript line even for simple form validations.

  • Dynamic form validations − Parsley can easily detect form modifications and adapts to its validations accordingly.

  • Tons of validators − There are tons of in-built validators that are present in parsley. We can also make use of Ajax validators if needed.

  • Highly Reliable − It is bug free, and has been strongly tested as well.

  • UX Focused − Parsley focuses on UI and UX, and we can even override almost every default behaviour of parsley to fit your exact needs.

How to Validate a Form Using Parsley

Now that we know a little about Parsley.js, it's time we focus on an example in which we will use Parsley. Consider the following "index.html" file in which we have a form with a simple JavaScript code embedded into it.

index.html

Example

<!DOCTYPE html> <html lang="en"> <head> <meta <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Parsely.js Example</title> <script src="https://code.jquery.com/jquery-3.6.0.min.js" integrity="sha256-/xUj+3OJU5yExlq6GSYGSHk7tPXikynS7ogEvDej/m4=" crossorigin="anonymous"></script> <script src="https://cdn.jsdelivr.net/gh/guillaumepotier/Parsley.js@2.9.2/dist/parsley.js"></script> </head> <body> <h2>Fill in the form and click the validate button at the bottom</h2> <form id="demo-form" data-parsley-validate=""> <label for="fullname">Enter Your Full Name * :</label> <input type="text" class="form-control" name="fullname" required=""> <br /><br /> <label for="email">Enter Your Email * :</label> <input type="email" class="form-control" name="email" data-parsleytrigger="change" required=""> <br /><br /> <label for="contactMethod">Please Enter Your Preferred Contact Method*:</label> Email: <input type="radio" name="contactMethod"id="contactMethodEmail" value="Email" required=""> Phone: <input type="radio" name="contactMethod" id="contactMethodPhone" value="Phone"> <br /><br /> <label for="hobbies">Enter Your Hobbies (Optional, but 2 minimum):</label> <p> Coding <input type="checkbox" name="hobbies[]" id="hobby1"value="ski" data-parsley-mincheck="2"><br> Walking <input type="checkbox"name="hobbies[]" id="hobby2" value="run"><br> Eating <input type="checkbox" name="hobbies[]" id="hobby3" value="eat"><br> Sleeping <input type="checkbox" name="hobbies[]" id="hobby4" value="sleep"><br> Traveling <input type="checkbox" name="hobbies[]" id="hobby5" value="read"><br> Writing <input type="checkbox" name="hobbies[]" id="hobby6" value="code"><br></p> <p> <label for="heard">Heard about us via *:</label> <select id="heard" required=""> <option value="">Choose..</option> <option value="press">Press</option> <option value="net">Internet</option> <option value="mouth">Word of mouth</option> <option value="other">Other..</option> </select> </p> <p> <label for="message">Message (20 chars min, 100 max) :</label> <textarea id="message" class="form-control" name="message" dataparsley- trigger="keyup" data-parsley-minlength="20" data-parsleymaxlength=" 100" data-parsley-minlength-message="Come on! You need to enter at least a 20 character comment.." data-parsley-validationthreshold="10"></textarea> </p> <br> <input type="submit" class="btn btn-default" value="validate"> </form> <script> $(function() { $('#demo-form').parsley().on('field:validated', function() { var ok = $('.parsley-error').length === 0; $('.bs-callout-info').toggleClass('hidden', !ok); $('.bs-callout-warning').toggleClass('hidden', ok); }) .on('form:submit', function() { return false; }); }); </script> </body> </html>

Click the "Edit and Run" button at the top to run this this code and see the output form.

Explanation

In this code, we have a form in which there are multiple text areas that expect different values. In each value, we have either a text keyword or a checkbox or an option.

Also, there is a "validate" button at the end of the code. When you click that button without having filled any of the forms, you will get a pop-up error from Parsley, and when you enter some fields that aren't what they expect, then you will get a validation error from Parsley.js.

You can run this code here, and then fill out different fields according to your choice for testing purpose.

Conclusion

In this tutorial, we used a simple example to demonstrate how you can use Parsley.js to validate forms in JavaScript.

raja
Updated on 11-Oct-2022 13:23:45

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