Individual user specific customization

I am building a website with individual user 开发者_StackOverflow社区customization in mind. So for instance, client #1 may say i want this feature to be designed for my account and then user #2 may say i want this added to my account. I was thinking of implementing a php if code where upon authentication those features will be loaded each time they login. But i have hundreds of thousands of customizations that i will be doing, to add each php code for each client will be terrible, is there a way i can do it more easily and with less stress?

Added from comments to particular answer: "Basically i am running the technical side of a business intelligence company. We offer various reports and information along with a dozen analytic tools. So one user might say i want all that you offer plus a custom feature where a particular area of the business is being analyzed and then upload to their account. As you can imagine there can be hundreds of such requests for a lot of accounts."

Your best bet is to either design yourself a framework, or find an existing one that supports this level of customization. Either way, it's not a small job, and launching code for each user leaves you prone to security issues and bugs arising from out-of-date methods as time goes on.

Ask yourself what kind of customizations you're doing, and if they can be abstracted away from the code level by (for example) a templating system.

Designs can fit in certain generic requirements. So until and unless you have some generic requirements, you can not do the design. For example, if requirement is for different look and feel for each client, you might go for dynamic theming. Similarly, for positional changes for different users, you can think of user profiling. For language, also you can keep the user language as part of the profile. Study different approaches for user profile management and then take a step ahead.

As others have said, its impossible to give a specific answer without knowing a lot more about what you mean by "Customization". The only sensible answer is the one you've already provided - i.e. to implement as much as possible of the variable behaviour in data.

This in itself may not be a trivial exercise - on one application I worked on, I designed a heuristic artificial intelligence engine (in PHP) which was hugely successful - but this was a fairly complex exercise in software engineering, and one I'd be hesitant to recommend to anyone who needs to ask the question.

Assuming that pushing all the application logic into data is not practical, then there are some other approaches you might consider, e.g. splitting the customizations into seperate php files (or templates if its just a display thing):

<?php

session_start();
/* do authentication checks...*/
$app=$_SESSION['user_profile'] . '/' . dirname($_SERVER['SCRIPT_NAME'] . '/inc.php');
if (! include_once($app)) {
   include_once('default/'.dirname($_SERVER['SCRIPT_NAME'].'/inc.php');
}
...

Although it would be posible to store php code in a database and eval it at runtime - I'd not recommend this as it opens the door to code injection attacks. OTOH, it may prove easier to implement the customizations in a different language and call that from PHP e.g. prolog.

C.