• Getting Started
• Basics
• Arrays
• Loop/Branch
• Functions
• OOP
• Libraries
• Files
• MySQL
• SQL
• PHP/MySQL
• Regex
• Email
• Date/Time
• Web
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Managing the Code: External Libraries

• Loading Code with "include"

• Loading Code with "require"

• Loading Code Once Only

• PHP Extensions and PECL

• PHP Libraries and PEAR

• LAB: Downloading an External Library

Loading Code with "include"

• What does "include" do?

  
  

  "include" loads a file into the currently running program

• Why would you want to use "include"

  
  

  Normally you would use "include" to load libraries of functions,
  class definitions, define constants, or initialize variables

• How can using "include" help you build websites?

  
  

  Using "include" helps break up your code into smaller files
  which makes development and troubleshooting easier

Loading Code with "require"

• What does "require" do?

  
  

  "require" does the same thing that "include" does:
  it loads files into the currently running program

• What is the difference between "require" and "include"?

  
  

  "require" generates a fatal error if the file is not found, whereas "include" generates a warning

• Why would you use "require" instead of "include"?

  
  

  Use "require" for files which are critical to the operation of your website

Loading Code Once Only

• Why is it important to only "include" or "require" a file one time only?

  
  

  PHP does not allow duplicate definitions of a function or class

• How do you make sure a file has been included one time only?

  
  

  Use "include_once" or "require_once"

• Why not use "include_once" or "require_once" all the time?

  
  

  There is no problem using "include_once" or "require_once" all the time

• Why is this important for website development?

  
  

  Sometimes a library of functions or a class definition
  will have dependencies on other functions or classes

PHP Extensions and PECL

• What is a PHP extension?

  
  

  A PHP extension is written in "C" language and will add new
  functions or classes to the PHP language running on your server

• What does "PECL" stand for?

  
  

  PHP Extension Community Library

• What is available on pecl.php.net?

  
  

  Many categories of extensions

• How do you install an extension on a website?

  
  

  First you need to download the extension. After that installation instructions vary. The easiest way is to install "pecl" on your server, and use "pecl download" and "pecl install"

• What impact will this have on developing a website?

  
  

  An extension can add specific functionality you need
  to get a certain job done on your website

PHP Libraries and PEAR

• What is a PEAR package?

  
  

  A PEAR package is a library of functions or classes written in PHP

• What does "PEAR" stand for?

  
  

  PHP Extension Archive Repository

• What is available on pear.php.net?

  
  

  Many categories of packages

• How do you install a PEAR package?

  
  

  You can either download and unzip the package into a directory which is in your php.ini "include_path" or use the "pear" command

• How does a PEAR package improve a website?

  
  

  A PEAR package can add specific functionality you need
  to get a certain job done on your website

LAB: Downloading an External Library

• What is the purpose of this lab?

  
  

  • PHPMailer vastly expands the capabilities of the PHP "mail()" function
  • PHPMailer will be used in another lab (see the chapter on email)
  • In this lab you will download and install PHPMailer
  • Following the installation you will run a sample code file as a test

• Reviewing PHPMailer Documentation ...

  
  

  • Go to the website "https://github.com/Synchro/PHPMailer"
  • Scroll down the page
  • Review the installation procedure

• Downloading and installing PHPMailer ...

  
  

  • From the PHPMailer website click "ZIP"
  • Open up the ZIP file
  • Extract the "PHPMailer-master" folder to /path/to/xampp/php/pear
  • Change the folder name to "PHPMailer"

• Quick Test ...

  
  

  • Under "htdocs/sweetscomplete" create a folder "mailtest"
  • From the WorkingFiles folder for this chapter, copy these files into "mailtest":
    external_lab_test.php, contents.html, phpmailer*.gif
  • In your editor open the file sweetscomplete/mailtest/external_lab_test.php
  • Change "$address" to your email address
  • From your browser run "http://localhost/sweetscomplete/mailtest/external_lab_test.php"
  • If your computer is configured to send mail, you should see the message appear in your inbox
  • Otherwise, look in the /path/to/xampp/mailoutput folder for a text file of the message