rowid,title,contents,year,author,author_slug,published,url,topic 335,Naughty or Nice? CSS Background Images,"Web Standards based development involves many things – using semantically sound HTML to provide structure to our documents or web applications, using CSS for presentation and layout, using JavaScript responsibly, and of course, ensuring that all that we do is accessible and interoperable to as many people and user agents as we can. This we understand to be good. And it is good. Except when we don’t clearly think through the full implications of using those techniques. Which often happens when time is short and we need to get things done. Here are some naughty examples of CSS background images with their nicer, more accessible counterparts. Transaction related messages I’m as guilty of this as others (or, perhaps, I’m the only one that has done this, in which case this can serve as my holiday season confessional) We use lovely little icons to show status messages for a transaction to indicate if the action was successful, or was there a warning or error? For example: “Your postal/zip code was not in the correct format.” Notice that we place a nice little icon there, and use background colours and borders to convey a specific message: there was a problem that needs to be fixed. Notice that all of this visual information is now contained in the CSS rules for that div:
Your postal/zip code was not in the correct format.
Your postal/zip code was not in the correct format.
“Speech marks. Curly quotes. That annoying thing cool people do with their fingers to emphasize a buzzword, shortly before you hit them.”So far nothing will look any different, aside form the curlies looking a bit nicer. I know we’ve just added extra markup, but the benefits as far as accessibility are concerned are good enough for me, and of course there are no images to download. The CSS OK, easy stuff first. Our first rule .bqstart floats the span left, changes the color, and whacks the font-size up to an exuberant 700%. Our second rule .bqend does the same tricks aside from floating the curly to the right. .bqstart { float: left; font-size: 700%; color: #FF0000; } .bqend { float: right; font-size: 700%; color: #FF0000; } That gives us this, which is rubbish. I’ve highlighted the actual span area with outlines: Note that the curlies don’t even fit inside the span! At this stage on IE 6 PC you won’t even see the quotes, as it only places focus on what it thinks is in the div. Also, the quote text is getting all spangled. Fiddle with margin and padding Think of that span outline box as a window, and that you need to position the curlies within that window in order to see them. By adding some small adjustments to the margin and padding it’s possible to position the curlies exactly where you want them, and remove the excess white space by defining a height: .bqstart { float: left; height: 45px; margin-top: -20px; padding-top: 45px; margin-bottom: -50px; font-size: 700%; color: #FF0000; } .bqend { float: right; height: 25px; margin-top: 0px; padding-top: 45px; font-size: 700%; color: #FF0000; } I wanted the blocks of my curlies to align with the quote text, whereas you may want them to dig in or stick out more. Be aware however that my positioning works for IE PC and Mac, Firefox and Safari. Too much tweaking seems to break the magic in various browsers at various times. Now things are fitting beautifully: I must admit that the heights, margins and spacing don’t make a lot of sense if you analyze them. This was a real trial and error job. Get it working on Safari, and IE would fail. Sort IE, and Firefox would go weird. Finished The final thing looks ace, can be resized, looks cool without styles, and can be edited with CSS at any time. Here’s a real example (note that I’m specifying Lucida Grande and then Verdana for my curlies): “Speech marks. Curly quotes. That annoying thing cool people do with their fingers to emphasize a buzzword, shortly before you hit them.” Browsers happy As I said, too much tweaking of margins and padding can break the effect in some browsers. Even now, Firefox insists on dropping the closing curly by approximately 6 or 7 pixels, and if I adjust the padding for that, it’ll crush it into the text on Safari or IE. Weird. Still, as I close now it seems solid through resizing tests on Safari, Firefox, Camino, Opera and IE PC and Mac. Lovely. It’s probably not perfect, but together we can beat the evil typographic limitations of the web and walk together towards a brighter, more aligned world. Merry Christmas.",2005,Simon Collison,simoncollison,2005-12-21T00:00:00+00:00,https://24ways.org/2005/swooshy-curly-quotes-without-images/,business 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 326,Don't be eval(),"JavaScript is an interpreted language, and like so many of its peers it includes the all powerful eval() function. eval() takes a string and executes it as if it were regular JavaScript code. It’s incredibly powerful and incredibly easy to abuse in ways that make your code slower and harder to maintain. As a general rule, if you’re using eval() there’s probably something wrong with your design. Common mistakes Here’s the classic misuse of eval(). You have a JavaScript object, foo, and you want to access a property on it – but you don’t know the name of the property until runtime. Here’s how NOT to do it: var property = 'bar'; var value = eval('foo.' + property); Yes it will work, but every time that piece of code runs JavaScript will have to kick back in to interpreter mode, slowing down your app. It’s also dirt ugly. Here’s the right way of doing the above: var property = 'bar'; var value = foo[property]; In JavaScript, square brackets act as an alternative to lookups using a dot. The only difference is that square bracket syntax expects a string. Security issues In any programming language you should be extremely cautious of executing code from an untrusted source. The same is true for JavaScript – you should be extremely cautious of running eval() against any code that may have been tampered with – for example, strings taken from the page query string. Executing untrusted code can leave you vulnerable to cross-site scripting attacks. What’s it good for? Some programmers say that eval() is B.A.D. – Broken As Designed – and should be removed from the language. However, there are some places in which it can dramatically simplify your code. A great example is for use with XMLHttpRequest, a component of the set of tools more popularly known as Ajax. XMLHttpRequest lets you make a call back to the server from JavaScript without refreshing the whole page. A simple way of using this is to have the server return JavaScript code which is then passed to eval(). Here is a simple function for doing exactly that – it takes the URL to some JavaScript code (or a server-side script that produces JavaScript) and loads and executes that code using XMLHttpRequest and eval(). function evalRequest(url) { var xmlhttp = new XMLHttpRequest(); xmlhttp.onreadystatechange = function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { eval(xmlhttp.responseText); } } xmlhttp.open(""GET"", url, true); xmlhttp.send(null); } If you want this to work with Internet Explorer you’ll need to include this compatibility patch.",2005,Simon Willison,simonwillison,2005-12-07T00:00:00+00:00,https://24ways.org/2005/dont-be-eval/,code 320,DOM Scripting Your Way to Better Blockquotes,"Block quotes are great. I don’t mean they’re great for indenting content – that would be an abuse of the browser’s default styling. I mean they’re great for semantically marking up a chunk of text that is being quoted verbatim. They’re especially useful in blog posts.
Notice that you can’t just put the quoted text directly between theProgressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference.
tags. In order for your markup to be valid, block quotes may only contain block-level elements such as paragraphs. There is an optional cite attribute that you can place in the openingtag. This should contain a URL containing the original text you are quoting:Great! Except… the default behavior in most browsers is to completely ignore the cite attribute. Even though it contains important and useful information, the URL in the cite attribute is hidden. You could simply duplicate the information with a hyperlink at the end of the quoted text:Progressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference.
But somehow it feels wrong to have to write out the same URL twice every time you want to quote something. It could also get very tedious if you have a lot of quotes. Well, “tedious” is no problem to a programming language, so why not use a sprinkling of DOM Scripting? Here’s a plan for generating an attribution link for every block quote with a cite attribute: Write a function called prepareBlockquotes. Begin by making sure the browser understands the methods you will be using. Get all the blockquote elements in the document. Start looping through each one. Get the value of the cite attribute. If the value is empty, continue on to the next iteration of the loop. Create a paragraph. Create a link. Give the paragraph a class of “attribution”. Give the link an href attribute with the value from the cite attribute. Place the text “source” inside the link. Place the link inside the paragraph. Place the paragraph inside the block quote. Close the for loop. Close the function. Here’s how that translates to JavaScript: function prepareBlockquotes() { if (!document.getElementsByTagName || !document.createElement || !document.appendChild) return; var quotes = document.getElementsByTagName(""blockquote""); for (var i=0; iProgressive Enhancement, as a label for a strategy for Web design, was coined by Steven Champeon in a series of articles and presentations for Webmonkey and the SxSW Interactive conference.
tags. You can style the attribution link using CSS. It might look good aligned to the right with a smaller font size. If you’re looking for something to do to keep you busy this Christmas, I’m sure that this function could be greatly improved. Here are a few ideas to get you started: Should the text inside the generated link be the URL itself? If the block quote has a title attribute, how would you take its value and use it as the text inside the generated link? Should the attribution paragraph be placed outside the block quote? If so, how would you that (remember, there is an insertBefore method but no insertAfter)? Can you think of other instances of useful information that’s locked away inside attributes? Access keys? Abbreviations?",2005,Jeremy Keith,jeremykeith,2005-12-05T00:00:00+00:00,https://24ways.org/2005/dom-scripting-your-way-to-better-blockquotes/,code 315,Edit-in-Place with Ajax,"Back on day one we looked at using the Prototype library to take all the hard work out of making a simple Ajax call. While that was fun and all, it didn’t go that far towards implementing something really practical. We dipped our toes in, but haven’t learned to swim yet. So here is swimming lesson number one. Anyone who’s used Flickr to publish their photos will be familiar with the edit-in-place system used for quickly amending titles and descriptions on photographs. Hovering over an item turns its background yellow to indicate it is editable. A simple click loads the text into an edit box, right there on the page. Prototype includes all sorts of useful methods to help reproduce something like this for our own projects. As well as the simple Ajax GETs we learned how to do last time, we can also do POSTs (which we’ll need here) and a whole bunch of manipulations to the user interface – all through simple library calls. Here’s what we’re building, so let’s do it. Getting Started There are two major components to this process; the user interface manipulation and the Ajax call itself. Our set-up is much the same as last time (you may wish to read the first article if you’ve not already done so). We have a basic HTML page which links in the prototype.js file and our own editinplace.js. Here’s what Santa dropped down my chimney: Edit-in-Place with Ajax Edit-in-place
Dashing through the snow on a one horse open sleigh.
So that’s our page. The editable item is going to be thecalled desc. The process goes something like this: Highlight the area onMouseOver Clear the highlight onMouseOut If the user clicks, hide the area and replace with a