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Useful PHP Tips for Beginners – Part 1

Some useful tips and techniques that can be used to improve and optimise your php code. Note that these php tips are meant for beginners and not those who are already using mvc frameworks etc.

1. Do not use relative paths , instead define a ROOT path

Its quite common to see such lines :

This approach has many drawbacks :

It first searches for directories specified in the include paths of php , then looks from the current directory.
So many directories are checked.

When a script is included by another script in a different directory , its base directory changes to that of the including script.

Another issue , is that when a script is being run from cron , it may not have its parent directory as the working directory.

So its a good idea to have absolute paths :

Now this is an absolute path and will always stay constant. But we can improve this further. The directory /var/www/project can change , so do we change it everytime ? No instead we make it portable using magic constants like __FILE__ . Take a closer look :

So now even if you shift your project to a different directory , like moving it to an online server , the same code will run without any changes.

2. Dont use require , include , require_once or include_once

Your script could be including various files on top , like class libraries , files for utility and helper functions etc like this :

This is rather primitive. The code needs to be more flexible. Write up helper functions to include things more easily. Lets take an example :

See any difference ? You must. It does not need any more explanation.
You can improve this further if you wish to like this :

There are a lot of things that can be done with this :

Search multiple directories for the same class file.
Change the directory containing class files easily , without breaking the code anywhere.
Use similar functions for loading files that contain helper functions , html content etc.

3. Maintain debugging environment in your application

During development we echo database queries , dump variables which are creating problems , and then once the problem is solved , we comment them or erase them. But its a good idea to let everything stay and help in the long run

On your development machine you can do this :

And on the server you can do this :

4. Propagate status messages via session

Status messages are those messages that are generated after doing a task.

Code like that is common. Using variables to show status messages has limitations. They cannot be send via redirects (unless you propagate them as GET variables to the next script , which is very silly). In large scripts there might be multiple messages etc.

Best way is to use session to propagate them (even if on same page). For this there has to be a session_start on every page.

and in your script :

5. Make your functions flexible

When adding a single item you use the above function. When adding multiple items , will you create another function ? NO. Just make the function flexible enough to take different kinds of parameters. Have a closer look :

So now the same function can accept different kinds of output. The above can be applied in lots of places to make your code more agile.

6. Omit the closing php tag if it is the last thing in a script

I wonder why this tip is omitted from so many blog posts on php tips.

This will save you lots of problem. Lets take an example :

A class file super_class.php

Now index.php

And you will get Headers already send error. Why ? because the “super extra character” has been echoed , and all headers went along with that. Now you start debugging. You may have to waste many hours to find the super extra space.

Hence make it a habit to omit the closing tag :

That’s better.

7. Collect all output at one place , and output at one shot to the browser

This is called output buffering. Lets say you have been echoing content from different functions like this :

Instead of doing like that , first collect all output in one place. You can either store it inside variables in the functions or use ob_start and ob_end_clean. So now it should look like

So why should you do output buffering :

  • You can change the output just before sending it to browser if you need to. Think about doing some str_replaces , or may be preg_replaces or may be adding some extra html at the end like profiler/debugger output
  • Its a bad idea to send output to browser and do php processing at the same time. Have you ever seen a website where there is a Fatal error in the sidebar or in a box in the middle of the screen. You know why that happens ? Because processing and output are being mixed.

8. Send correct mime types via header when outputting non-html content

Lets echo some xml.

Works fine. But it needs some improvement.

Note that header line. That line tells the browser that the content is xml content. So the browser can handle it correctly. Many javascript libraries also rely on header information.

Similarly for javascript , css , jpg image , png image :

Javascript

CSS

9. Set the correct character encoding for a mysql connection

Ever faced a problem that unicode/utf-8 characters are stored in mysql table correctly , phpmyadmin also shows them correct , but when you fetch them and echo on your page they do not show up correctly. The secret is mysql connection collation.

Once you connect to the database , its a good idea to set the connections characterset. This is a must when you are working with multiple languages in your application.

Otherwise what will happen ? You will see lots of boxes and ???????? in non english text.

10. Use htmlentities with the correct characterset option

Prior to php 5.4 the default character encoding used is ISO-8859-1 which cannot display characters like À â etc.

Php 5.4 onwards the default encoding will be UTF-8 which will solve most problems , but still better be aware about it if your application is multilingual.

 

Prakash S

Prakash S

I would like to introduce myself as a Software professional opting for the career in software industry. I'm Prakash S, a MCA graduate and trained as industry level practice for Software technology. Basically I am a PHP Developer but now days exploring more in HTML5, CSS, AngularJS and jQuery libraries.