{"rowid": 142, "title": "Revealing Relationships Can Be Good Form", "contents": "A few days ago, a colleague of mine \u2013 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 \u2013 was running through a prototype I had put together for some user testing. As with a lot of prototypes, there was an element of \u2018smoke and mirrors\u2019 to make things look like they were working. \n\nOne 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 \u2013 clicking on that link would cause the form to mimic a change event on the radio button. But it wasn\u2019t working for him. \n\nWhy 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\u2019d placed around the text). Bah! There goes my time-saver.\n\nSo, 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\u2019s a web-standards-loving guy to do? Make a bit more bleedin\u2019 obvious, that\u2019s what! \n\nThe Mouse Pointer Trick\n\nOK, 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\u2019s derided because the hand icon is usually used for links, and some would argue that using this technique is misleading:\n\nlabel {\n\tcursor: pointer;\n}\n\nThis is not a new idea, though, and you didn\u2019t come here for this. The point is that with something very simple, you\u2019ve made the label element discoverable. But there are other ways that you can do this that are web standards friendly and won\u2019t upset the purists quite so much as the hand/pointer trick. Time to wheel in the JavaScript trolley jack \u2026\n\nOur Old Friend AddEvent\n\nFirst things, first, you\u2019ll 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:\n\nfunction addEvent(elm, evType, fn, useCapture)\n{\n\tif(elm.addEventListener)\n\t{\n\t\telm.addEventListener(evType, fn, useCapture);\n\t\treturn true;\n\t}\n\telse if (elm.attachEvent)\n\t{\n\t\tvar r = elm.attachEvent('on' + evType, fn);\n\t\treturn r;\n\t}\n\telse\n\t{\n\t\telm['on' + evType] = fn;\n\t}\n}\n\nFinding All Your Labels\n\nOnce you\u2019ve linked to the addEvent function (or embedded it on the page), you can start to get your JavaScripting fingers a-flexing. Now, what I\u2019m suggesting you do here is:\n\n\n\tIdentify all the label elements on the page by working your way through the DOM\n\tFind out the value of the for attribute for each label that you uncover\n\tAttach a behaviour or two to each of those label elements \u2013 and to the input that the label relates to (identified with the for attribute)\n\n\nHere\u2019s the technobabble version of the steps above:\n\nfunction findLabels()\n{\n\tvar el = document.getElementsByTagName(\"label\");\n\tfor (i=0;i<el.length;i++)\n\t{\n\t\tvar thisId = el[i].getAttribute(\"for\");\n\t\tif ((thisId)==null)\n\t\t{\n\t\t\tthisId = el[i].htmlFor;\n\t\t}\n\t\tif(thisId!=\"\")\n\t\t{\n\t\t\t//apply these behaviours to the label\n\t\t\tel[i].onmouseover = highlightRelationship;\n\t\t\tel[i].onmouseout = hideRelationship;\n\t\t}\n\t}\n}\nfunction highlightRelationship()\n{\n\tvar thisId = this.getAttribute(\"for\");\n\tif ((thisId)==null)\n\t{\n\t\tthisId = this.htmlFor;\n\t}\t\n\tthis.className=\"showRel\";\n\tdocument.getElementById(thisId).className=\"showRel\";\n\t//if (document.getElementById(thisId).type==\"text\") document.getElementById(thisId).select();\n}\nfunction hideRelationship()\n{\n\tvar thisId = this.getAttribute(\"for\");\n\tif ((thisId)==null)\n\t{\n\t\tthisId = this.htmlFor;\n\t}\t\n\tthis.className=\"\";\n\tdocument.getElementById(thisId).className=\"\";\n}\naddEvent(window, 'load', findLabels, false);\n\nUsing the above script, you can apply a CSS class (I\u2019ve 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\u2019d call \u2018fancy\u2019, 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. \n\n\n\n\tBackground colour changes on hover\n\tBackground colour change + mouse pointer trick\n\tBackground colour change + mouse pointer trick + text selection\n\n\nHopefully you\u2019ll agree that using an unobtrusive piece of JavaScript you can make otherwise \u2018shy\u2019 elements like the label reveal their true colours. Although you might want to tone down the colours from the ones I\u2019ve used in this demo!", "year": "2006", "author": "Ian Lloyd", "author_slug": "ianlloyd", "published": "2006-12-13T00:00:00+00:00", "url": "https://24ways.org/2006/revealing-relationships-can-be-good-form/", "topic": "ux"}