Useful PHP Tips Revisited Link Day 5,6,7,8

5. Favor str_replace() Over ereg_replace() and preg_replace() Link

We hate to sound disparaging, but this tip demonstrates the sort of misunderstanding that leads to the same misuse it’s trying to prevent. It’s an obvious truth that string functions are faster at string matching than regular expression functions, but the author’s attempt to draw a corollary from this fails miserably:

If you’re using regular expressions, then ereg_replace() and preg_replace() will be much faster than str_replace().

Because str_replace() does not support pattern matching, this statement makes no sense. The choice between string functions and regular expression functions comes down to which is fit for purpose, not which is faster. If you need to match a pattern, use a regular expression function. If you need to match a string, use a string function.

6. Use Ternary Operators Link

The benefit of the ternary operator is debatable (there’s only one, by the way). Here is a line of code from an audit we performed recently:

<?php
 
$host = strlen($host) > 0 ? $host : htmlentities($host);
 
?>

Oops! The author actually means to escape $host if the string length is greater than zero, but instead accidentally does the opposite. Easy mistake to make? Maybe. Easy to miss during a code audit? Certainly. Concision doesn’t necessarily make the code any better.

The ternary operator may be fine for one-liners, prototypes, and templates, but we strongly believe that an ordinary conditional statement is almost always better. PHP is descriptive and verbose. We think code should be, too.

7. Memcached Link

Disk access is slow. Network access is slow. Databases typically use both.

Memory is fast. Using a local cache avoids the overhead of network and disk access. Combine these truths and you get memcached, a “distributed memory object caching system” originally developed for the Perl-based blogging platform LiveJournal.

If your application isn’t distributed across multiple servers, you probably don’t need memcached. Simpler caching approaches — serializing data and storing it in a temporary file, for example — can eliminate a lot of redundant work on each request. In fact, this is the sort of low-hanging fruit we consider when helping our clients tune their apps.

One of the easiest and most universal ways to cache data in memory is to use the shared memory helpers in APC, a caching system originally developed by our colleague George Schlossnagle. Consider the following example:

<?php
 
$feed = apc_fetch('news');
 
if ($feed === FALSE) {
    $feed = file_get_contents('http://example.org/news.xml');
    // Store this data in shared memory for five minutes.
    apc_store('news', $feed, 300);
}
 
// Do something with $feed.
 
?>

With this type of caching, you don’t have to wait on a remote server to send the feed data for every request. Some latency is incurred — up to five minutes in this example — but this can be adjusted to as close to real time as your app requires.

8. Use a Framework Link

All decisions have consequences. We appreciate frameworks — in fact, the main developers behind CakePHP and Solar work with us at OmniTI — but using one doesn’t magically make what you’re doing better.

In December, our colleague Paul Jones wrote an article for PHP Advent called The Framework as Franchise, in which he compares frameworks to business franchises. He refers to a suggestion by Michael Gerber from his book “The E-Myth Revisited”:

Gerber notes that to run a successful business, the entrepreneur needs to act as if he is going to sell his business as a franchise prototype. It is the only way the business owner can make the business operate without him being personally involved in every decision.

This is good advice. Whether you’re using a framework or defining your own standards and conventions, it’s important to consider the value from the perspective of future developers.

Although we would love to give you a universal truth, extending this idea to suggest that a framework is always appropriate isn’t something we’re willing to do. If you ask us whether you should use a framework, the best answer we could give is, “It depends.”

Further more details: 

PHP TRAINING IN KATHMANDU

PHP TRAINING IN LALITPUR