Tags: complete

15

sparkline

Wednesday, August 26th, 2020

Submitting a form with datalist

I’m a big fan of HTML5’s datalist element and its elegant design. It’s a way to progressively enhance any input element into a combobox.

You use the list attribute on the input element to point to the ID of the associated datalist element.

<label for="homeworld">Your home planet</label>
<input type="text" name="homeworld" id="homeworld" list="planets">
<datalist id="planets">
 <option value="Mercury">
 <option value="Venus">
 <option value="Earth">
 <option value="Mars">
 <option value="Jupiter">
 <option value="Saturn">
 <option value="Uranus">
 <option value="Neptune">
</datalist>

It even works on input type="color", which is pretty cool!

The most common use case is as an autocomplete widget. That’s how I’m using it over on The Session, where the datalist is updated via Ajax every time the input is updated.

But let’s stick with a simple example, like the list of planets above. Suppose the user types “jup” …the datalist will show “Jupiter” as an option. The user can click on that option to automatically complete their input.

It would be handy if you could automatically submit the form when the user chooses a datalist option like this.

Well, tough luck.

The datalist element emits no events. There’s no way of telling if it has been clicked. This is something I’ve been trying to find a workaround for.

I got my hopes up when I read Amber’s excellent article about document.activeElement. But no, the focus stays on the input when the user clicks on an option in a datalist.

So if I can’t detect whether a datalist has been used, this best I can do is try to infer it. I know it’s not exactly the same thing, and it won’t be as reliable as true detection, but here’s my logic:

  • Keep track of the character count in the input element.
  • Every time the input is updated in any way, check the current character count against the last character count.
  • If the difference is greater than one, something interesting happened! Maybe the user pasted a value in …or maybe they used the datalist.
  • Loop through each of the options in the datalist.
  • If there’s an exact match with the current value of the input element, chances are the user chose that option from the datalist.
  • So submit the form!

Here’s how that translates into DOM scripting code:

document.querySelectorAll('input[list]').forEach( function (formfield) {
  var datalist = document.getElementById(formfield.getAttribute('list'));
  var lastlength = formfield.value.length;
  var checkInputValue = function (inputValue) {
    if (inputValue.length - lastlength > 1) {
      datalist.querySelectorAll('option').forEach( function (item) {
        if (item.value === inputValue) {
          formfield.form.submit();
        }
      });
    }
    lastlength = inputValue.length;
  };
  formfield.addEventListener('input', function () {
    checkInputValue(this.value);
  }, false);
});

I’ve made a gist with some added feature detection and mustard-cutting at the start. You should be able to drop it into just about any page that’s using datalist. It works even if the options in the datalist are dynamically updated, like the example on The Session.

It’s not foolproof. The inference relies on the difference between what was previously typed and what’s autocompleted to be more than one character. So in the planets example, if someone has type “Jupite” and then they choose “Jupiter” from the datalist, the form won’t automatically submit.

But still, I reckon it covers most common use cases. And like the datalist element itself, you can consider this functionality a progressive enhancement.

Monday, April 20th, 2020

Better Form Inputs for Better Mobile User Experiences | CSS-Tricks

Here’s one simple, practical way to make apps perform better on mobile devices: always configure HTML input fields with the correct type, inputmode, and autocomplete attributes. While these three attributes are often discussed in isolation, they make the most sense in the context of mobile user experience when you think of them as a team.

This is an excellent deep dive with great advice:

You may think that you are familiar with the basic autocomplete options, such as those that help the user fill in credit card numbers or address form fields, but I’d urge you to review them to make sure that you are aware of all of the options. The spec lists over 50 values!

Saturday, January 25th, 2020

HTML attributes to improve your users’ two factor authentication experience - Twilio

The many ways of improving a single form field in HTML.

I love these kinds of deep dives into markup!

Thursday, September 19th, 2019

An HTML attribute potentially worth $4.4M to Chipotle - Cloud Four

When I liveblogged Jason’s talk at An Event Apart in Chicago, I included this bit of reporting:

Jason proceeds to relate a long and involved story about buying burritos online from Chipotle.

Well, here is that story. It’s a good one, with some practical takeaways (if you’ll pardon the pun):

  1. Use HTML5 input features
  2. Support autofill
  3. Make autofill part of your test plans

Thursday, May 30th, 2019

Is CSS Turing Complete? | Lara Schenck

This starts as a good bit of computer science nerdery, that kind of answers the question in the title:

Alone, CSS is not Turing complete. CSS plus HTML plus user input is Turing complete!

And so the takeaway here is bigger than just speculation about Turing completeness:

Given that CSS is a domain-specific language for styling user interface, this makes a lot of sense! CSS + HTML + Human = Turing complete.

At the end of that day, as CSS developers that is the language we really write. CSS is incomplete without HTML, and a styled interface is incomplete without a human to use it.

Friday, July 6th, 2018

Insult Generator

Testing the theory that putting the word “total”, “complete”, or “absolute” in front of any noun automatically makes for an excellent insult.

Saturday, April 28th, 2018

alphagov/accessible-autocomplete: An autocomplete component, built to be accessible.

If you’re looking for an accessible standalone autocomplete script, this one from GDS looks very good (similar to Lea’s awesomplete).

Friday, April 20th, 2018

Cancelling Requests with Abortable Fetch

This is a really good use-case for cancelling fetch requests: making API calls while autocompleting in search.

Wednesday, March 22nd, 2017

Improve Your Billing Form’s UX In One Day – Smashing Magazine

A few straightforward steps for improving the usability of credit card forms. The later steps involve JavaScript but the first step uses nothing more than straight-up HTML.

Sunday, October 16th, 2016

Oversharing with the browser’s autofill / Stoyan’s phpied.com

Equal parts clever and scary. By using autocomplete in HTML and some offscreen positioning in CSS, it’s possible to extract some unexpected personal information.

I expect browsers will be closing these holes pretty quickly.

Friday, May 27th, 2016

» Autofill: What web devs should know, but don’t

Jason takes good look at the browser support for autocomplete values and then makes a valiant attempt to make up for the complete lack of documentation for Safari’s credit card scanning.

Monday, December 28th, 2015

Touch Keyboard Type ‘Cheat Sheet’ - Labs - Baymard Institute

A useful primer on which combinations of attributes and values work best for which form fields: type, autocomplete, autocorrect, and autocapitalize.

Sunday, February 22nd, 2015

Awesomplete: Ultra lightweight, highly customizable, simple autocomplete, by Lea Verou

Lea wasn’t happy with the lack of styling and extensibility of the datalist element, so she rolled her own lightweight autocomplete/type-ahead widget, and she’s sharing it with the world.

Sunday, April 28th, 2013

Google Poetics

The accidental beauty in Google’s autosuggest algorithm.

Friday, April 1st, 2011

YouTube - Being a Google Autocompleter

Yeah, it’s an April Fool’s video (lamest day on the internet) but this is amusing.

Being a Google Autocompleter