Having fun with HTML5 – Range type input

You can become a serverless blackbelt. Enrol to my 4-week online workshop Production-Ready Serverless and gain hands-on experience building something from scratch using serverless technologies. At the end of the workshop, you should have a broader view of the challenges you will face as your serverless architecture matures and expands. You should also have a firm grasp on when serverless is a good fit for your system as well as common pitfalls you need to avoid. Sign up now and get 15% discount with the code yanprs15!

Besides the much talked about video tag, HTML5 also introduced a couple of new input types, one of which is a rather interesting range input type which basically translates to a slider bar control:

image

The range input type is currently supported by the latest versions of Safari, Chrome and Opera while other browsers such as Firefox simply treat the field as a textbox.

There are four available attributes – min, max, step and value. min and max should be self explanatory, step determines the size of each increment/decrement and value is the current value of the slider and also determines the placement of the slider when the element is loaded (if not specified, the slider will appear at the centre of the control when it’s first loaded):

<input type="range" min="0" max="200" step="5"></input>

image

<input type="range" min="0" max="200" value="0" step="5"></input>

image

I talked about the new border radius property being introduced in CSS3 in my previous blog post, and with a little JQuery I’ve put together a quick demo here of how a 400px by 400px square looks as the border radius changes.

If you look at the source of the page you will see that I added a changeBorder javascript function to handle the onchange event fired by the slider, which dynamically updates the HTML content of an internal CSS class called mySliderBarStyles using the current value of the slider control:

<input id="mySliderBar" type="range" min="0" max="200" value="0" step="5"
       onchange="changeBorder(this.value)"></input>
…
<script type="text/javascript">
    function changeBorder(newValue) {
        var newRadius = newValue + "px";
        // set the html content of the label showing the current radius value
        $("#rangeValue").html(newRadius);
        // set the style with the new radius value
        $("#mySliderBarStyles").html(
            "#myDiv { -webkit-border-radius: " + newRadius + "; }"
        );
    }
</script>
…
<style type="text/css" id="mySliderBarStyles"></style>

References:

Dive Into HTML5

Liked this article? Support me on Patreon and get direct help from me via a private Slack channel or 1-2-1 mentoring.
Subscribe to my newsletter


Hi, I’m Yan. I’m an AWS Serverless Hero and I help companies go faster for less by adopting serverless technologies successfully.

Are you struggling with serverless or need guidance on best practices? Do you want someone to review your architecture and help you avoid costly mistakes down the line? Whatever the case, I’m here to help.

Hire me.


Skill up your serverless game with this hands-on workshop.

My 4-week Production-Ready Serverless online workshop is back!

This course takes you through building a production-ready serverless web application from testing, deployment, security, all the way through to observability. The motivation for this course is to give you hands-on experience building something with serverless technologies while giving you a broader view of the challenges you will face as the architecture matures and expands.

We will start at the basics and give you a firm introduction to Lambda and all the relevant concepts and service features (including the latest announcements in 2020). And then gradually ramping up and cover a wide array of topics such as API security, testing strategies, CI/CD, secret management, and operational best practices for monitoring and troubleshooting.

If you enrol now you can also get 15% OFF with the promo code “yanprs15”.

Enrol now and SAVE 15%.


Check out my new podcast Real-World Serverless where I talk with engineers who are building amazing things with serverless technologies and discuss the real-world use cases and challenges they face. If you’re interested in what people are actually doing with serverless and what it’s really like to be working with serverless day-to-day, then this is the podcast for you.


Check out my new course, Learn you some Lambda best practice for great good! In this course, you will learn best practices for working with AWS Lambda in terms of performance, cost, security, scalability, resilience and observability. We will also cover latest features from re:Invent 2019 such as Provisioned Concurrency and Lambda Destinations. Enrol now and start learning!


Check out my video course, Complete Guide to AWS Step Functions. In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. There is something for everyone from beginners to more advanced users looking for design patterns and best practices. Enrol now and start learning!