Responsive website

Responsive Web Design

The Internet took off quicker than anyone would have predicted, growing like crazy. Now, for the past few years, mobile growth has exploded onto the scene. The growth of mobile Internet usage is also far out pacing that of general Internet usage growth.

These days it is hard to find someone who doesn’t own a mobile device, or multiple, connected to the Internet. In the UK there are more mobile phones than people, and should trends continue mobile Internet usage will surpass that of desktop Internet usage within the year.

With the growth in mobile Internet usage comes the question of how to build websites suitable for all users. The industry response to this question has become responsive web design, also known as RWD.

Responsive Overview

Responsive web design is the practice of building a website suitable to work on every device and every screen size, no matter how large or small, mobile or desktop. Responsive web design is focused around providing an intuitive and gratifying experience for everyone. Desktop computer and cell phone users alike all benefit from responsive websites.

Responsive vs. Adaptive vs. Mobile

For some the term responsive may not be new, and others might be even more acquainted with the terms adaptive or mobile. Which may leave you wondering what exactly is the difference between all of them.

Responsive and adaptive web design are closely related, and often transposed as one in the same. Responsive generally means to react quickly and positively to any change, while adaptive means to be easily modified for a new purpose or situation, such as change. With responsive design websites continually and fluidly change based on different factors, such as viewport width, while adaptive websites are built to a groups of preset factors. A combination of the two is ideal, providing the perfect formula for functional websites. Which term is used specifically doesn’t make a huge difference.

Mobile, on the other hand, generally means to build a separate website commonly on a new domain solely for mobile users. While this does occasionally have it’s place, it normally isn’t a great idea. Mobile websites can be extremely light but they do come with the dependencies of a new code base and browser sniffing, all of which can become an obstacle for both developers and users.

Currently the most popular technique lies within responsive web design, favoring design that dynamically adapts to different browser and device viewports, changing layout and content along the way. This solution has the benefits of being all three, responsive, adaptive, and mobile.

Flexible Layouts

Responsive web design is broken down into three main components, including flexible layouts, media queries, and flexible media. The first part, flexible layouts, is the practice of building the layout of a website with a flexible grid, capable of dynamically resizing to any width. Flexible grids are built using relative length units, most commonly percentages or em units. These relative lengths are then used to declare common grid property values such as width, margin, or padding.

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HTML 5 Validation…

1. The ‘required’ attribute

The simplest change you can make to your forms is to mark a text input field as ‘required’:

Your Name: <input type="text" name="name" required>

Your Name:
This informs the (HTML5-aware) web browser that the field is to be considered mandatory. Different browsers may mark the input box in some way (Firefox 4 Beta adds a red box-shadow by default), display a warning (Opera) or even prevent the form from being submitted if this field has no value. Hopefully these behaviours will converge in future releases.

We have actually created our own valid/invalid formatting using CSS to override the browser default, but more on that later. That’s why you may see something like the following in the example above:

HTML5 required example

Before you type anything into the box a red marker is shown. As soon as a single character has been entered this changes to a green marker to indicate that the input is ‘valid’.

Using CSS you can place markers inside or alongside the input box, or simply use background colours and borders as some browsers do by default.

The required attribute can also be applied to checkboxes when you want them to be mandatory.

2. Different INPUT types

This is where HTML5 really gets interesting and more useful. Along with the text input type, there are now a host of other options, including email, url, number, tel, date and many others.

On the iPhone/iPad the different input types are associated with different keyboards, making it easier for people to complete your online forms. In other web browsers they can be used in combination with the required attribute to limit or give advice on allowable input values.

INPUT type=”email”

By changing the input type to email while also using the required attribute, the browser can be used to validate (in a limited fashion) email addresses:

Email Address: <input type="email" name="email" required placeholder="Enter a valid email address">

Note that for this example we’ve made use of another HTML5 attribute placeholder which lets us display a prompt or instructions inside the field – something that previously had to be implemented using messy onfocus and onblur JavaScript events.

The above code displays an input box as follows:

Email Address:
Again, different browsers implement this differently. In Opera it’s sufficient to enter just *@* for the input to be accepted. In Safari, Chrome and Firefox you need to enter at least *@-.-. Obviously neither example is very limiting, but it will prevent people from entering completely wrong values, such as phone number, strings with multiple ‘@’s or spaces.

Here is how it appears in Safari (with our CSS formatting to show the (in)valid state):

HTML5 email required example

INPUT type=”url”

In a similar fashion to the email input type above, this one is designed to accept only properly-formatted URLs. Of course it currently does nothing of the kind, but later you will see how to improve it’s behaviour using the pattern attribute.

Website: <input type="url" name="website" required>

Again, the input box appears as normal:

Website:
This time the minimum requirement for most browsers is one or more letters followed by a colon. Again, not very helpful, but it will stop people trying to input their email address or other such nonsense.

As mentioned above, we can improve on this by making use of the pattern attribute which accepts a JavaScript regular expression. So the code above becomes:

Website: <input type="url" name="website" required pattern="https?://.+">

Now our input box will only accept text starting with http:// or https:// and at least one additional character:

Website: starting with http
If you’re not yet familiar with regular expressions, you really should make it a priority to learn. For those already familiar, note that the ^ and $ are already implicit so the input has to match the entire expression. Pattern modifiers are not supported.

If anyone wants to contribute a more thorough expression to test for valid email or url format, feel free to post it using the Feedback form.

INPUT type=”number” and type=”range”

The number and range input types also accept parameters for min, max and step. In most cases you can leave out step as it defaults to 1.

Here you see an example including both a number input, typically displayed as a ‘roller’ and a range input displayed as a ‘slider’:

Age: <input type="number" size="6" name="age" min="18" max="99" value="21"><br> Satisfaction: <input type="range" size="2" name="satisfaction" min="1" max="5" value="3">

As with other HTML5 input types, browsers that don’t recognise the new options will default to simple text inputs. For that reason it’s a good idea to include a size for the input box.

Age Satisfaction (1-5)
The slider option is a bit bizarre in that no values are displayed, but may be useful for more ‘analog’ inputs. There are some bugs with the number input in that if you don’t set a max value, clicking ‘down’ with the input blank will result in a very large number.

Here is how the two inputs are displayed in Safari:

HTML5 number and range example

and in Opera:

HTML5 number and range example

They are currently not supported in Firefox 4 Beta.

If you want to restrict the input of a text field to numbers without having the up/down arrows associated with the input box, you can always just set the input type to text and use a pattern of “\d+” (one or more numbers).

INPUT type=”password”

We have a separate article with details on validating passwords using HTML5, including JavaScript code for customising the browser generated alert messages.

3. Other HTML5 INPUT types

Other HTML5 input types include:

  • color
  • date
  • datetime
  • datetime-local
  • month
  • search
  • tel
  • time
  • week

The search input will, in some browsers, change the styles to match the browser or operating system default search field format. You can see this demonstrated in the Search input above.

The tel input type is handy for the iPhone as it selects a different input keyboard. There is no pattern-matching set by default so you would have to implement that yourself using the pattern attribute to accept only certain characters.

The color input is meant to let you select a hex-code from a colour wheel – or similar – but as yet doesn’t appear to have been implemented in the wild.

The other date– and time-related options do have an effect at least in Opera, with pop-up calendars and other devices appearing to assist with input. While it would be great to see something like this in every browser, for now you probably need to stick with the ubiquitous JavaScript plugins.

4. Styling valid/invalid inputs using CSS

While the code we’re using is slightly more complicated, this should get you started:

input:required:invalid, input:focus:invalid { /* insert your own styles for invalid form input */ -moz-box-shadow: none; }

The first set of styles can be used to mark an input box as ‘invalid’, by adding an icon, colouring the text or borders or similar. It will apply to inputs that are required but empty, or to inputs that have a required format/pattern which hasn’t yet been met.

The -moz-box-shadow style is there just to prevent Firefox 4 Beta from adding it’s default red border.

For inputs that are both required and ‘valid’ you can use the following:

input:required:valid { /* insert your own styles for valid form input */ }

Some of the articles below, particularly the first two, provide other style/scripting options and solutions for supporting older browsers.

5. Sample styling using images and sprites

As shown above, once you’ve added HTML5 attributes to your form elements, they can be easily styled using CSS so that each input field is clearly marked as valid or invalid.

<style type="text/css"> input:required:invalid, input:focus:invalid { background-image: url(/images/invalid.png); background-position: right top; background-repeat: no-repeat; } input:required:valid { background-image: url(/images/valid.png); background-position: right top; background-repeat: no-repeat; } </style>