Toggle Text Field Values with jQuery

UPDATED: Project moved to Git!

I saw this post on the CSS Tricks Snippet Feed which addresses a commonly desired form behavior: to provide default text in an INPUT element that disappears when the user enters that field. The example provided works, but I have a couple issues with it:

  1. Uses inline JavaScript, and must be reapplied to each element affected
  2. Repeats the contents of the value attribute
  3. The default text is not replaced if the user exits the field without entering new data

So I created a possible solution, using jQuery:

HTML

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<input type="text" value="Place default text here" />

JavaScript

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jQuery( function(){
  $( 'input[type="text"]' ).each( function(){
    $(this).attr( 'title', $(this).val() )
      .focus( function(){
        if ( $(this).val() == $(this).attr('title') ) {
          $(this).val( '' );
        }
      } ).blur( function(){
        if ( $(this).val() == '' || $(this).val() == ' ' ) {
          $(this).val( $(this).attr('title') );
        }
      } );
  } );
} );

This script first iterates over each of the text input to assign a semantic text attribute, helpful not only in storing the default value, but also providing a tool-tip for reference as the user interacts with the page. It then assigns behaviors for both the onfocus and onblur events, eliminating the need to respecify data for comparison. The script is cleanly separated from the markup and, using jQuery, additional specifications may be made so as to only affect children of a particular FIELDSET or only those that possess a certain class.

I hope you find this snippet useful, and feel free to comment if you have additional information to share.


UPDATED!

We, as designers and developers, cannot help but go back to review our sites and code to make updates and revisions as our skills, philosophies and tastes change. In this spirit, I would like to offer an alternative to the above JavaScript snippet. The one above, in my opinion, is lacking in the following ways:

  1. Applies the behavior to all input[type="text"] elements indiscriminantly.
  2. Overwrites any existing title attribute content
  3. Does not account for existing text field values resulting from pre-population or validation.

So with that in mind, here’s the new solution:

HTML

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<input type="text" title="Place default assistive text here (e.g. First Name)" />
<input type="text" title="Default assistive text (e.g. E-Mail Address)" value="invalid@ddr.ess" />

jQuery Plugin

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$.fn.toggleField = function(){
  return this.each(function(){
    var $this = $(this);
    if($this.val() === '' && $this.attr('title') !== ''){
      $this.val($this.attr('title'));
    }
    $this.bind('focus blur', function(){
      var $this = $(this);
      if($this.val() === $this.attr('title')){
        $this.val('');
      }else if($this.val() === '' || $this.val() === ' '){
        $this.val($this.attr('title'));
      }
    });
  });
};

JavaScript

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jQuery(document).ready(function(){
  $('input[type="text"]').toggleField();
});

By converting the behavior into a plugin, it becomes chainable and more flexible. Perhaps in a future version it would be useful accommodate additional field types or textarea elements. I have also packaged the plugin for download (zipToggleField jQuery Plugin). I look forward to seeing your questions or suggestions in the comments below!

Project Moved to Git

After further review and consideration, I decided to make some more changes to the plug-in to take advantage of some of the new features promoted in HTML5. Specifically the placeholder attribute, since this is essentially the behavior that we are trying to mimic. Here is an example:

<label for="email">Email:</label>
<input type="email" id="email" name="email" title="Enter a valid email address" placeholder="account@domain.tld"/>

The previous zip file will remain available above, but the toggleField.jquery.js project updates will progress on GitHub instead. Thanks to everyone for your suggestions and support!


Examples of jQuery In Action

The jQuery foundation has created a new site showcasing designs that Use jQuery. They currently have only about 30 samples organized by effect/function category, but they do accept submissions so show off that great interface or behavior that you’ve created!


25 Tips to Developing with jQuery

Jon Hobbs-Smith from the UK web development firm TVI Design has compiled a list of 25 tips to making your jQuery-powered applications easier to script and faster loading. While some of the items may be considered common knowledge (such as return false; for click events to prevent default behavior) the list provides excellent links and resources to people interested in using the Write Less, Do More JavaScript Library.

Considering almost all the recent updates to the framework relate to improving speed, why not take fullest advantage of them in making your application as responsive as possible?


Visualize Your Markup with Processing

I recently discovered an interesting applet developed by Aharef in 2006 that uses the Processing programming language to graph the element tree of a given web page.

For instance the current markup on this site gets rendered like this:

An HTML DOM Visualizer Applet
Graph of http://blog.paulgueller.com

According to the documentation and examples, the colors represent:

  • blue: links (the A tag)
  • red: tables (TABLE, TR and TD tags)
  • greenDIV tags
  • violet:  images (the IMG tag)
  • yellow: forms (FORM, INPUT, TEXTAREA, SELECT and OPTION tags)
  • orange: linebreaks and blockquotes (BR, P, and BLOCKQUOTE tags)
  • black: the HTML tag, the root node
  • gray: all other tags

Processing is an open-source programming language and development environment used for prototyping and producing images, animation, and interactions within a visual context. The code-graphing applet requires Java, but processing.js has made the language more widely accessible and available for experimentation.


sIFR + jQuery = Custom Typography Without Image Replacement

If you haven’t heard of it already, sIFR lets you appease all those designers by integrating custom fonts onto your standards-compliant web page without turning them into images. On its own, it’s not a small or straightforward undertaking, requiring a number of additional CSS and JavaScript files to function. However, the recent release of the sIFR jQuery plug-in should make it more accessible to developers:

First, jQuery makes finding the item(s) that you want to replace as easy as using CSS. Then, the jQuery sIFR Plugin does all the work of figuring out the text, files, sizes, colors, and any other configurations needed for the conversion. The jQuery sIFR plugin is fully configurable and can choose how little or how much you want to customize the display of the sIFRed text. Finally, the jQuery Flash Plugin does a most excellent job of embedding the sIFR flash into your web page. After all is said and done, you should have beautiful sIFR replaced text with consistent behavior across all major browsers.

All the resources are available for download from the developer’s site, as well a simple API and usage examples for easy customization.


UPDATE

While sIFR may have its uses it also has a number of serious drawbacks. Check out some of the emerging web typography technologies, including Cufón, @font-face and Typekit.


The Evolution of Sizzle

Among the many interesting things discussed in the interview with Sitepoint, John Resig again brought up a project titled Sizzle. No, he’s not talking about adding POW BANG SHAZAM to our web layouts; it’s an initiative to create standardized and easily-implemented CSS-based selectors for JavaScript.

Aside from its lightweight and extensible nature, jQuery’s ability to easily assign behaviors and attributes to custom-created arrays of elements without much hassle is one of its most appealing features. Using a similar scheme for other libraries, frameworks or even in stand-alone cases would not only simplify programming (goodbye document.getElementsByTagName “for” loops!) but would improve the language as a whole by making scripts more readable and accessible.


Using jQuery for DHTML Drop-Down Menus

You may have heard of the Suckerfish Dropdowns featured on A List Apart (which use CSS and JavaScript along with valid HTML to create vertical or horizontal “drop-down” menus) and the the extended revised version Son of Suckerfish, but if you’re already using the jQuery library on your site the code to mimic the :hover pseudo-class gets even simpler.

Instead of:

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sfHover = function() {
  var sfEls = document.getElementById("nav").getElementsByTagName("LI");
  for (var i=0; i<sfels .length; i++)="" {="">
    sfEls[i].onmouseover=function() {
      this.className+=" sfhover";
    }
    sfEls[i].onmouseout=function() {
      this.className=this.className.replace(new RegExp(" sfhover\\b"), "");
    }
  }
}
if (window.attachEvent) window.attachEvent("onload", sfHover);
</sfels>

You only need:

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jQuery('#nav li').hover(function(){
 	$(this).addClass('sfhover'); //mouseover
 }, function(){
 	$(this).removeClass('sfhover'); //mouseout
 });

or, simpler yet:

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jQuery('#nav li').bind("mouseover mouseout", function(){ $(this).toggleClass('sfhover'); });

Such is the beauty of using css-style selectors to build an array of affected elements. Of course, you must make sure the code is wrapped in $(document).ready(function(){…});, but there is no need to modify the window.onload event in this example. Otherwise, refer to the code provided in the above examples to get your markup and formatting styles in place.