| 142 |
Revealing Relationships Can Be Good Form |
A few days ago, a colleague of mine – someone I have known for several years, who has been doing web design for several years and harks back from the early days of ZDNet – was running through a prototype I had put together for some user testing. As with a lot of prototypes, there was an element of ‘smoke and mirrors’ to make things look like they were working.
One part of the form included a yes/no radio button, and selecting the Yes option would, in the real and final version of the form, reveal some extra content. Rather than put too much JavaScript in the prototype, I took a preverbial shortcut and created a link which I wrapped around the text next to the radio button – clicking on that link would cause the form to mimic a change event on the radio button. But it wasn’t working for him.
Why was that? Because whereas I created the form using a <label> tag for each <input> and naturally went to click on the text rather than the form control itself, he was going straight for the control (and missing the sneaky little <a href> I’d placed around the text). Bah! There goes my time-saver.
So, what did I learn? That a web professional who has used the Internet for years had neither heard of the <label> tag, nor had he ever tried clicking on the text. It just goes to show that despite its obvious uses, the label element is not as well known as it rightfully deserves to be. So, what’s a web-standards-loving guy to do? Make a bit more bleedin’ obvious, that’s what!
The Mouse Pointer Trick
OK, this is the kind of thing that causes some people outrage. A dead simple way of indicating that the label does something is to use a snippet of CSS to change the default mouse cursor to a hand. It’s derided because the hand icon is usually used for links, and some would argue that using this technique is misleading:
label {
cursor: pointer;
}
This is not a new idea, though, and you didn’t come here for this. The point is that with something very simple, you’ve made the label element discoverable. But there are other ways that you can do this that are web standards friendly and won’t upset the purists quite so much as the hand/pointer trick. Time to wheel in the JavaScript trolley jack …
Our Old Friend AddEvent
First things, first, you’ll need to use the addEvent function (or your favourite variation thereof) that Scott Andrew devised and make that available to the document containing the form:
function addEvent(elm, evType, fn, useCapture)
{
if(elm.addEventListener)
{
elm.addEventListener(evType, fn, useCapture);
return true;
}
else if (elm.attachEvent)
{
var r = elm.attachEvent('on' + evType, fn);
return r;
}
else
{
elm['on' + evType] = fn;
}
}
Finding All Your Labels
Once you’ve linked to the addEvent function (or embedded it on the page), you can start to get your JavaScripting fingers a-flexing. Now, what I’m suggesting you do here is:
Identify all the label elements on the page by working your way through the DOM
Find out the value of the for attribute for each label that you uncover
Attach a behaviour or two to each of those label elements – and to the input that the label relates to (identified with the for attribute)
Here’s the technobabble version of the steps above:
function findLabels()
{
var el = document.getElementsByTagName("label");
for (i=0;i<el.length;i++)
{
var thisId = el[i].getAttribute("for");
if ((thisId)==null)
{
thisId = el[i].htmlFor;
}
if(thisId!="")
{
//apply these behaviours to the label
el[i].onmouseover = highlightRelationship;
el[i].onmouseout = hideRelationship;
}
}
}
function highlightRelationship()
{
var thisId = this.getAttribute("for");
if ((thisId)==null)
{
thisId = this.htmlFor;
}
this.className="showRel";
document.getElementById(thisId).className="showRel";
//if (document.getElementById(thisId).type=="text") document.getElementById(thisId).select();
}
function hideRelationship()
{
var thisId = this.getAttribute("for");
if ((thisId)==null)
{
thisId = this.htmlFor;
}
this.className="";
document.getElementById(thisId).className="";
}
addEvent(window, 'load', findLabels, false);
Using the above script, you can apply a CSS class (I’ve called it showRel) to the elements when you hover over them. How you want it to look is up to you, of course. Here are a few examples of the idea. Note: the design is not exactly what you’d call ‘fancy’, and in the examples there is one input that looks broken but it is deliberately moved away from the label it relates to, just to demonstrate that you can show the relationship even from afar.
Background colour changes on hover
Background colour change + mouse pointer trick
Background colour change + mouse pointer trick + text selection
Hopefully you’ll agree that using an unobtrusive piece of JavaScript you can make otherwise ‘shy’ elements like the label reveal their true colours. Although you might want to tone down the colours from the ones I’ve used in this demo! |
2006 |
Ian Lloyd |
ianlloyd |
2006-12-13T00:00:00+00:00 |
https://24ways.org/2006/revealing-relationships-can-be-good-form/ |
ux |
| 327 |
Improving Form Accessibility with DOM Scripting |
The form label element is an incredibly useful little element – it lets you link the form field unquestionably with the descriptive label text that sits alongside or above it. This is a very useful feature for people using screen readers, but there are some problems with this element.
What happens if you have one piece of data that, for various reasons (validation, the way your data is collected/stored etc), needs to be collected using several form elements?
The classic example is date of birth – ideally, you’ll ask for the date of birth once but you may have three inputs, one each for day, month and year, that you also need to provide hints about the format required. The problem is that to be truly accessible you need to label each field. So you end up needing something to say “this is a date of birth”, “this is the day field”, “this is the month field” and “this is the day field”. Seems like overkill, doesn’t it? And it can uglify a form no end.
There are various ways that you can approach it (and I think I’ve seen them all). Some people omit the label and rely on the title attribute to help the user through; others put text in a label but make the text 1 pixel high and merging in to the background so that screen readers can still get that information. The most common method, though, is simply to set the label to not display at all using the CSS display:none property/value pairing (a technique which, for the time being, seems to work on most screen readers). But perhaps we can do more with this?
The technique I am suggesting as another alternative is as follows (here comes the pseudo-code):
Start with a totally valid and accessible form
Ensure that each form input has a label that is linked to its related form control
Apply a class to any label that you don’t want to be visible (for example superfluous)
Then, through the magic of unobtrusive JavaScript/the DOM, manipulate the page as follows once the page has loaded:
Find all the label elements that are marked as superfluous and hide them
Find out what input element each of these label elements is related to
Then apply a hint about formatting required for input (gleaned from the original, now-hidden label text) – add it to the form input as default text
Finally, add in a behaviour that clears or selects the default text (as you choose)
So, here’s the theory put into practice – a date of birth, grouped using a fieldset, and with the behaviours added in using DOM, and here’s the JavaScript that does the heavy lifting.
But why not just use display:none? As demonstrated at Juicy Studio, display:none seems to work quite well for hiding label elements. So why use a sledge hammer to crack a nut? In all honesty, this is something of an experiment, but consider the following:
Using the DOM, you can add extra levels of help, potentially across a whole form – or even range of forms – without necessarily increasing your markup (it goes beyond simply hiding labels)
Screen readers today may identify a label that is set not to display, but they may not in the future – this might provide a way around
By expanding this technique above, it might be possible to visually change the parent container that groups these items – in this case, a fieldset and legend, which are notoriously difficult to style consistently across different browsers – while still retaining the underlying semantic/logical structure
Well, it’s an idea to think about at least. How is it for you? How else might you use DOM scripting to improve the accessiblity or usability of your forms? |
2005 |
Ian Lloyd |
ianlloyd |
2005-12-03T00:00:00+00:00 |
https://24ways.org/2005/improving-form-accessibility-with-dom-scripting/ |
code |