HTML, XHTML, and CSS Bible, Fourth Edition

Chapter 40. Testing and Validating CSS

IN THIS CHAPTER

• Testing syntax as you create styles

• A word about formatting

• Validating CSS

As you have seen in this book, HTML and CSS provide a yin and yang approach to the content and formatting of Web documents. As such, each depends on the other being complete, sturdy, and robust.

In Chapter 23 you saw the benefits to well-formed and validated HTML. This chapter explores the other piece of the equation — well-formed and validated CSS.

Testing Syntax as You Create Styles

The best and easiest method to ensure your CSS is valid is to check its syntax as you create it. This means using a syntax highlighting, syntax checking, and text auto-insertion CSS editor for even the first draft of your styles.

Syntax highlighting involves using different colors for different portions of code. When editing CSS, for example, an editor might display the selector portion of a style in green, the braces in white, the properties in red, and the values in yellow. If a piece of the style is missing, the color of the previous element usually bleeds into the next section of the file. Using these visual cues, you can easily see the various pieces of the whole and recognize missing portions (such as a closing brace). Figure 40-1 shows the popular Linux editor vim with syntax highlighting turned on.

Syntax checking involves actively checking code as you type it and sometimes offering to auto-insert the next required piece for you. When editing CSS, for example, an editor might ...