3. Our server applies any modifications

Well, if we're at this stage, we should have gotten all the user's text in and checked that everything is in order to proceed. So, now the real fun begins...

Several things happen behind the scenes before we get onto the real fun of processing text.

• HTML tags are stripped from text. (HTML is the language that makes web pages, and all sorts of things could happen if we allowed those to get altered by the text-altering program, so we remove them all... besides if you wanted to change webpage code, use the webpage feature)
• Entities are decoded. (Some special characters, including most common accented letters are wrapped up as 'entities'. Common ones include the copyright symbol, which is written as ©, the & (ampersand) which is written as & and things like that. Basically, we translate the different entities like © and & into their respective symbols, © and & so that we can process them without any awkwardness and without any modification of them either. They might be important, so we leave them alone.)
• We then load the appropriate module for text translation, depending on whichever module was requested.

At that point, we are ready to go. In each module, there is a special function (miniature program) called 'revoice_text', which is given the text to work with and outputs the changed text back to text.php in order to set it up nicely for you.

The problem is that it is very hard to explain how revoice_text works, because it is different for every single module, and isn't just a case of searching for one thing and replacing it with another.

Some modules, like Morse code, can function pretty simply like that (although that removes anything which isn't a letter or digit before processing), but for example the Elmer Fudd module is a lot more complicated.

A snippet of the logic behind the Elmer Fudd module goes like this:

• Is the current letter an R?
• NO: return the R and move on to the next letter.
• YES:
• Is the letter after it a vowel?
• NO: return the two letters as they are and move on.
• YES:
• Is the letter before it a vowel?
• NO: Change the R to a W (careful of getting upper/lower case right) and move on.
• YES: Return the r and move on to the next letter.

At the time of writing, the Elmer Fudd dialect was actually the most complex on the site, due to the rulesets and the nature of rules being within rules. It is not implemented quite as above, but that it how the logic would follow through. (It is, in fact, written as a series of regular expressions)

Once the modifications are applied to all the text, it sends it back to text.php with a message which basically says, "All done, you can send that back to the browser now". text.php does a little more processing, converting special characters back into entites (as above), and setting up a bit more of the page. Basically, the result is the transformed text plus a bit of nice formatting and layout before it and again after it, with a function to change the method of transform to a different one if you wish.

At that point, text.php sends the entire new webpage back to the server and says "I'm all done" and the server then has to worry about it. Find out in part 4 what the server does once the PHP system has finished with text.php.