Posts Tagged 'Divs'

September 6, 2012

Tips and Tricks - jQuery equalHeights Plugin

Last month, I posted a blog about dynamically resizing divs with jQuery, and we received a lot of positive feedback about it. My quest to avoid iframes proved to be helpful, so I thought I'd share a few more esoteric jQuery tips and tricks that may be of use to the developers and designers in the audience. As I thought back about other challenges I've faced as a coder, a great example came to mind: Making divs equal height, regardless of the amount of content inside.

I haven't seen many elegant div-based solutions for that relatively simple (and common) task, so I've noticed that many people struggle with it. Often, developers will turn back to the "Dark Side" of using tables to format the content since all columns would have the same height as the tallest column by default:

JQuery Tutorial

It was easy theme table columns and to achieve the coveted 100% height that many designers seek, but emulating that functionality with divs proves to be much more difficult. A div is like the Superman of HTML elements (faster-loading, more flexible, more dynamic, etc.), and while it has super powers, it also has its own Kryptonite-like weaknesses ... The one relevant to this blog post being that floating three div elements next to each other isn't going to give you the look of a table:

JQuery Tutorial

Each of the three divs has its own height, so if you're doing something as simple as applying background colors, you're going to wind up with an aesthetically unpleasing result: It's going to look funky.

You could get into some nifty HTML/CSS workarounds, but many frustrated theme creators and designers will tell you that if your parent elements don't have a height of a 100%, you're just wasting coding lines. Some complex solutions create the illusion of all three divs being the same height (which is arguably better than setting fixed heights), but that complexity can be difficult to scale and repeat if you need to perform similar tasks throughout your site or your application. The easiest way to get the functionality you want and the simplicity you need: The jQuery equalHeights plugin!

With a few class declarations in your existing HTML, you get the results you want, and with equalHeights, you can also specify the minimum and maximum parameters so it will create scrollable divs if the tallest element happens to be higher than your specified maximum.

How to Use jQuery equalHeights

First and foremost, include your JQuery lirbraries in the <HEAD> of your document:

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
<script language="javascript" type="text/javascript" src="jquery.equalheights.js"></script>

The equalHeights plugin is not a hosted library, so you have to host the file on your server (here's the link again).

With the required libraries called in our document, it's time to make the magic happen in your HTML.

Create Your Divs

<div class="divHeight">This DIV is medium sized, not too big and not too small, but just right.</div>
<div class="divHeight">This DIV has a lot of useful content and media that the user can interact with, thus it's very tall.</div>
<div class="divHeight">This DIV is tiny. Period.</div>

To have them line up next to each other, you'd have them float:left; in your CSS, and now you need to apply the equalHeights function.

Call the equalHeights Plugin
In order for the script to recognize the height of the tallest element, you'd need to call $(document).ready just before the </body> tag on your page. This will ensure that the page loads before the function runs.

The call looks like this:

<script type="text/javascript">$(document).ready(function() {
$(".divHeight").equalHeights();
});</script>

If you want to specify a minimum and maximum (i.e. The div should be at least this tall and should be no taller than [adds scrollbar if the div size exceeds] the maximum), just add the parameters:

<script type="text/javascript">$(document).ready(function() {
$(".divHeight").equalHeights(300, 600);
});</script>

The initial call does not change the appearance of the divs, but the time it takes to do the resizing is so miniscule that users will never notice. After that call is made and the height is returned, each div with the class of divHeight will inherit the the same height, and your divs will be nice and pretty:

JQuery Tutorial

This trick saved me a lot of headache and frustration, so hopefully it will do the same for you too!

-Cassandra

August 8, 2012

No iFrames! Dynamically Resize Divs with jQuery.

It's no secret that iframes are one of the most hated methods of web page layouts in the web development world — they are horrible for SEO, user experience and (usually) design. I was recently charged with creating a page that needed functionality similar to what iframes would normally provide, and I thought I'd share the non-iframe way I went about completing that project.

Before I get into the nitty-gritty of the project, I should probably unpack a few of the reasons why iframes are shunned. When a search engine indexes a page with iframes, each iframe is accurately recorded as a separate page — iframes embed the content of one we page inside of another, so it makes sense. Because each of those "pages" is represented in a single layout, if a user wanted to bookmark your site, they'd probably have a frustrating experience when they try to return to your site, only to find that they are sent directly to the content in one of the frames instead of seeing the entire layout. Most often, I see when when someone has a navigation bar in one frame and the main content in the other ... The user will bookmark the content frame, and when they return to the site, they have no way to navigate the pages. So what's a developer to do?

The project I was tasked with required the ability to resize only certain sections of a page, while asynchronously shrinking another section so that the entire page would always stay the same size, with only the two sections inside changing size.

Let's look at an example with two divs, side by side on a web page:

iFrame Tutorial

One div will contain a navigation menu to jump to different pages of the website (#sidebar), and the second div will contain all the content for that page (#content). If some of the elements in #sidebar are too long to read with the default width of the div, we want to let the user freely resize the two divs without changing the width of the page.

Our task is straightforward: When #sidebar expands in width, also expand the navigation and shrink #content along with the main content inside #content. If #sidebar shrinks, the navigation, #content and main content would respond accordingly as well:

iFrame Tutorial

It's a relatively easy concept to do with iFrames ... But then you remember that iframes are no longer cool (yes, there was a time long ago when iframes were cool). I decided to turn to my favorite alternative — jQuery — and the fix was actually a lot easier than I expected, and it worked beautifully. Let's run through a step-by-step tutorial.

1. HTML

Lay out your two divs:

<div id="sidebar"> 
<div class="sidebar-menu">
<!-- all your sidebar/navigational items go here -->
</div>
</div>
<div id="content">
<!-- all your main content goes here -->
</div>

2. CSS

Style your divs:

#sidebar {
       width: 49%;
}
#content {
width: 49%;
        float: left;
}

3. jQuery

Now that we have our two divs side by side, let's apply some jQuery magic. To do that, Let's include our jQuery files in the <HEAD> of our document:

<link href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/base/jquery-ui.css" rel="stylesheet" type="text/css"/>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.5/jquery.min.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>

Now that we have the necessary scripts, we can write our function:

<script type="text/javascript">
  $(document).ready(function() {
    $( "#sidebar" ).resizable({      
    });
    $("#sidebar ").bind("resize", function (event, ui) {
            var setWidth = $("#sidebar").width();
            $('#content).width(1224-setWidth);
            $('.menu).width(setWidth-6);
        });
  });
</script>

I know that might seem like an intimidating amount of information, so let's break it down:

   $( "#sidebar" ).resizable({      
   });

This portion simply makes the div with the ID of "sidebar" resizable (which accomplishes 33% of what we want it to do).

   $("#sidebar ").bind("resize", function (event, ui) {

By using the .bind, we are able to trigger other events when #sidebar is called.

            var setWidth = $("#sidebar").width();
            $('#content).width(1224-setWidth);

This is where the magic happens. We're grabbing the current width of #sidebar and subtracting it from the width you want your site to be. This code is what keeps your page stays the same width with only the divs changing sizes.

            $('.menu).width(setWidth-6);

This part of the code that expands the contents in the navigation along with #sidebar.

You can see a working example of iframe-like functionality with jQuery here: http://jqueryui.com/demos/resizable/

The only part you won't find there is the trick to adjust a corresponding div's size to make it grow/shrink with the first ... I had a heck of a time searching that on the web, so hopefully this quick tutorial will help other developers who might be searching for this kind of functionality!

- Cassandra

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