Coding structure

[lerro]

I need some advice. What is the best way to structure my code?
There is the class which holds functions
Then there is the file that calls the class, then the functions to be used, then calls the template file to utilise the functions.

A layout similar to the one below;

Class file: Class:: Function - does calculation (no messages)

Process file: Process - does logic, holds logic (calls function, calls layout template)

Template file: template - holds layout (and for some, holds logic, e.g. loops, tables, etc)

---

My problem arises from the following, when creating a function, at times it's easier to specify what messages are displayed after a given logic step, for instance for user login

If invalid username
(echo message - wrong username)
else if invalid password
(echo message - wrong password)

But then if this is coded in the function, how can it work with the above structure, as when it's called in the process file, the "echo" message will happen within the process file when teh function is called before being passed onto the template.

Whereas using "return" is also limited and could not output something short.

How would i get messages to be displayed? The right messages being passed onto the template depending on the logic within the function

Does that mean creating a class that handles messages?

[johanafm]

lerro;10943245 wrote:

If invalid username
	(echo message - wrong username)
else if invalid password
	(echo message - wrong password)

But then if this is coded in the function, how can it work with the above structure, as when it's called in the process file, the "echo" message will happen within the process file when teh function is called before being passed onto the template.

Whereas using "return" is also limited and could not output something short.
[/QUOTE]

What's wrong with return? And why could it not "output something short"?

I don't believe you should actually tell the user which of password and username was wrong. If someone's trying to gain access you don't want to let them know they found an existing account and just lack the password. Or that a password happened to be right and they just need the account name.

So, returning true or false should do
[code=php]
function validCredentials($username, $password) {
	if (both_valid)
		return true;
	else
		return false;
}

And at some appropriate place in the code you check login. if (!validCredentials()), display login template. If you really want to display name error/password error (or similar thing under other circumstances), you could keep all login errors in the class that handles login (session class perhaps), and when the login template is displayed, start by displaying these errors.
But you might want keep all errors in its own class. Just keep adding errors until you display the template, at which point you check for errors and if there are any, displays them all and/or highlight missing form entry labels etc.

And even if you stick with your original approach, but change echo to return, you could return the exact same string as the echo would send. Store this string in a variable. At some later point, you'd echo said variable. So how is that any different than using echo in the first place?
Except the advantages from being able to process data in one tier and displaying/styling it in another.