Talk In Code

WordPress is a pretty neat blogging platform, but it falls over quite spectacularly when trying to write code in posts. I write a lot of code for Talk In Code and so I have understand what needs to be encoded to make code examples work.

For code example on Talk In Code I use the <code> tag and I encode the following characters.

• < into &lt;
• > into &gt;
• " into &quot;
• ' into &#39;

Note: You must be in HTML mode in your WordPress editor or everything will be double encoded.

If these characters are left in then WordPress will either keep them "as is" (ie, a <br /> will cause a line break) or it will convert them into non standard characters. For example, typing a ' (single quote) is straightforward, but when your users come to copy and paste the code to try it for themselves they find that the characters WordPress gives them cause the examples to fail. So every time you type a ' you have to encode it using &#39;. The following example shows why typing a single quote will break your code examples.

echo ‘Hello World’;

The same thing applies to double quotes, as in the following example.

echo “Hello World”;

WordPress will also try to guess what you are doing and add in tags where you don’t want them. The effect of this is to break your code tags if you leave any space in them. Take the following example of a 4 line snippet of code, with a blank line between line 2 and line 4.

line 1
line 2

line 4

This is because WordPress will see the blank line and try to add some tags in to make it look like it thought you wanted it. In order to stop this you need to put in a &nbsp; (non breaking space) character on any blank lines that you have. The following example fixes the previous example.

line 1
line 2
 
line 4

W3Schools is one of the best online tutorial sites available, but in addition to that, the site is completely free. When I can’t remember how a particular bit of syntax goes I can be pretty much certain that I will find it on this site. There are thousands of examples, explanations, quizzes and reference charts available and they don’t bog you down in too much detail. The examples on the site tell you exactly what you need to know about the subject so that you can copy the code and get on with the task at hand.

The site covers everything from web design with HTML, XHTML and CSS, client side scripting with JavaScript or VBScript, and even server side scripting with PHP or ASP. So if you are ever stuck on a problem or are trying to learn a language then you can do worse than reading through the examples contained in W3Schools.

When writing PHP I usually use the www.php.net site as this has more detailed information, but it is still an excelent resource for beginners of PHP.

Finally, although it is easy to think that W3Schools is run by the W3C, they completely independent.

Here are some of the regular expressions that I frequently use.

Find a blank line
^$

Spaces
[ \t]+
You can use this to break a text string apart into words.

Date
\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}
This will match anything in the format mm/dd/yyyy, or even dd/mm/yyyy.
[A-Z][a-z][a-z] [0-9][0-9]*, [0-9]{4}
Will match a formatted date, such as Mar 24, 2007.

Time
([1-9]|1[0-2]):[0-5]\d(:[0-5]\d(\.\d{1,3})?)?
This will match HH:MM or HH:MM:SS or HH:MM:SS.mmm.

IP Address
(((\d{1,2}|(1\d{2})|(2[0-4]\d)|25[0-5]))\.){3}((\d{1,2}|(1\d{2})|(2[0-4]\d)|25[0-5]))
This also checks to see that the IP address is within the range 0.0.0.0 to 255.255.255.255.

Email Address
([\w\-\.]+)@((\[([0-9]{1,3}\.){3}[0-9]{1,3}\])|(([\w\-]+\.)+)([a-zA-Z]{2,4}))
This is using a simple mechanism, the following expression uses the RFC standard for an email address format and so should match %99.99 of all email addresses.
[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?

Complete URLs
https?://(\w*:\w*@)?[-\w.]+(:\d+)?(/([\w/_.]*(\?\S+)?)?)?
This will match virtually any URL.

HTML Comments
<!-{2,}.*?-{2,}>

Inline Comments
//.*
This will match inline comments in C, PHP, Java, JavaScript etc.