PHP 8 Solutions : Dynamic Web Design and Development Made Easy

Make your websites more dynamic by adding a feedback form, creating a private area where members can upload images that are automatically resized, or storing all your content in a database. **David Powers** has updated his definitive book to incorporate the latest techniques and changes to PHP with the arrival of PHP 8. New features include named attributes, constructor property promotion, the stricter and more concise match expression, union types, and more.​ The problem is, you're not a programmer and the thought of writing code sends a chill up your spine. Or maybe you've dabbled a bit in PHP and MySQL, but you can't get past baby steps. If this describes you, then you've just found the right book. PHP powers four out of every five websites that use a server-side language. In combination with the MySQL database it’s ideal for creating dynamic websites. PHP and MySQL are free, easy to use, and provided by many web hosting companies in their standard packages. This book also covers MariaDB, a seamless replacement for MySQL that has been adopted on many web servers. Unfortunately, most PHP books either expect you to be an expert already or force you to go through endless exercises of little practical value. In contrast, this book gives you real value right away through a series of practical examples that you can incorporate directly into your sites, optimizing performance and adding functionality such as file uploading, email feedback forms, image galleries, content management systems, and much more. Each solution is created with not only functionality in mind, but also visual design. But this book doesn't just provide a collection of ready-made scripts: each PHP solution builds on what's gone before, teaching you the basics of PHP and database design quickly and painlessly. You’ll learn how to optimize your code using object-oriented programming (OOP) techniques. By the end of the book, you'll have the confidence to start writing your own scripts or―if you prefer to leave that task to others―to adapt existing scripts to your own requirements. Right from the start, you're shown how easy it is to protect your sites by adopting secure coding practices. **What You Will Learn** * Design and build dynamic PHP-based web sites and applications * Get started right away through practical examples that you can reuse * Incorporate PHP 8 elements including named attributes, constructor property promotion, and union types * Understand the subtle, but important differences between switch and match * Work with the latest PHP 8 techniques, innovations, and best practices **Who This Book Is For** Readers should ideally have some prior exposure to web development using PHP. Table of Contents About the Author About the Technical Reviewer Acknowledgments Introduction Chapter 1: What Is PHP 8? How PHP Has Grown How PHP Makes Pages Dynamic Creating Pages That Think for Themselves How Hard Is PHP to Use and Learn? Can I Just Copy and Paste the Code? How Safe Is PHP? What’s New in PHP 8? What Software Do I Need to Write PHP? What to Look for When Choosing a PHP Editor So Let’s Get On with It... Chapter 2: Getting Ready to Work with PHP Checking Whether Your Web Site Supports PHP Deciding Where to Test Your Pages What You Need for a Local Test Environment Setting Up on Windows Getting Windows to Display Filename Extensions Choosing a Web Server Installing an All-in-One Package on Windows Setting Up on macOS Installing MAMP Testing and Configuring MAMP Where to Locate Your PHP Files (Windows and Mac) Checking Your PHP Settings Displaying the Server Configuration with phpinfo() Editing php.ini What’s Next? Chapter 3: How to Write PHP Scripts PHP: The Big Picture Telling the Server to Process PHP Embedding PHP in a Web Page Storing PHP in an External File Using Variables to Represent Changing Values Naming Variables Assigning Values to Variables Ending Commands with a Semicolon Commenting Scripts Single-Line Comments Multiline Comments Using Arrays to Store Multiple Values PHP’s Built-In Superglobal Arrays Understanding When to Use Quotes Special Cases: True, False, and Null Making Decisions Making Comparisons Using Indenting and Whitespace for Clarity Using Loops for Repetitive Tasks Using Functions for Preset Tasks Displaying PHP Output Using the Short Echo Tag Joining Strings Together Working with Numbers Understanding PHP Error Messages Why Is My Page Blank? PHP Quick Checklist Chapter 4: PHP: A Quick Reference Using PHP in an Existing Web Site Data Types in PHP Checking the Data Type of a Variable Explicitly Changing a Variable’s Data Type Checking Whether a Variable Has Been Defined Doing Calculations with PHP Arithmetic Operators Using the Increment and Decrement Operators Determining the Order of Calculations Combining Calculations and Assignment Adding to an Existing String All You Ever Wanted to Know About Quotes—and More How PHP Treats Variables Inside Strings Using Escape Sequences Inside Double Quotes Embedding Associative Array Elements in a String Avoiding the Need to Escape Quotes with Heredoc Syntax Creating Arrays Building an Indexed Array Building an Associative Array Creating an Empty Array Multidimensional Arrays Using print_r() to Inspect an Array The Truth According to PHP Explicit Boolean Values Implicit Boolean (“Truthy” and “Falsy”) Values Making Decisions by Comparing Two Values Testing More Than One Condition Using the switch Statement for Decision Chains Using a match Expression for Decision Chains Using the Ternary Operator Setting a Default Value with the Null Coalescing Operator Executing Code Repeatedly with a Loop Loops Using while and do . . . while The Versatile for Loop Looping Through Arrays and Objects with foreach Breaking Out of a Loop Modularizing Code with Functions Passing Values to Functions Setting Default Values for Arguments Variable Scope: Functions as Black Boxes Returning Values from Functions Generators: A Special Type of Function That Keeps on Giving Passing by Reference: Changing the Value of an Argument Functions That Accept a Variable Number of Arguments Automatically Unpacking an Array Passed to a Function Optionally Specifying Data Types Specifying Multiple Data Types Using Named Arguments Where to Locate Custom-Built Functions Creating Anonymous Functions Using the Concise Anonymous Syntax of Arrow Functions Understanding PHP Classes and Objects Using PHP Built-In Classes Building Custom Classes Accessing Methods and Properties in a Class Setting the Visibility of Class Methods, Properties, and Constants Using Constructor Property Promotion Declaring and Using Class Constants Using a Namespace to Avoid Naming Conflicts Importing a Namespaced Class Handling Errors and Exceptions Creating New Variables Dynamically Now to the Solutions Chapter 5: Lightening Your Workload with Includes Including Code from External Files Introducing the PHP Include Commands Where PHP Looks for Include Files PHP Solution 5-1: Moving the Menu and Footer to Include Files Choosing the Right Filename Extension for Includes PHP Solution 5-2: Testing the Security of Includes PHP Solution 5-3: Automatically Indicating the Current Page PHP Solution 5-4: Automating a Page’s Title from Its Filename PHP Solution 5-5: Handling Missing Variables Creating Pages with Changing Content PHP Solution 5-6: Automatically Updating a Copyright Notice PHP Solution 5-7: Displaying a Random Image PHP Solution 5-8: Adding a Caption to the Random Image Preventing Errors with Include Files Checking the Existence of Variables Checking Whether a Function or Class Has Been Defined Suppressing Error Messages on a Live Web Site Using the Error Control Operator Turning Off display_errors in the PHP Configuration Turning Off display_errors in an Individual File PHP Solution 5-9: Redirecting When an Include File Can’t Be Found Why Can’t I Use Site Root–Relative Links with PHP Includes? Document-Relative Links Links Relative to the Site Root Links Inside Include Files Choosing Where to Locate Your Include Files Security Considerations with Includes Adjusting Your include_path Editing the include_path in php.ini or .user.ini Using .htaccess to Change the include_path Using set_include_path() Nesting Include Files Chapter Review Chapter 6: Bringing Forms to Life How PHP Gathers Information from a Form Understanding the Difference Between post and get Getting Form Data with PHP Superglobals Processing and Validating User Input Creating a Reusable Script PHP Solution 6-1: Preventing Cross-Site Scripting in a Self-Processing Form PHP Solution 6-2: Making Sure Required Fields Aren’t Blank Preserving User Input When a Form Is Incomplete PHP Solution 6-3: Creating Sticky Form Fields Filtering Out Potential Attacks PHP Solution 6-4: Blocking Email Addresses That Contain Suspect Content Sending Email Using Additional Email Headers Safely PHP Solution 6-5: Adding Headers and Automating the Reply Address PHP Solution 6-6: Building the Message Body and Sending the Mail Troubleshooting mail() Handling Multiple-Choice Form Elements PHP Solution 6-7: Handling Radio Button Groups PHP Solution 6-8: Handling Check-Box Groups PHP Solution 6-9: Using a Drop-Down Option Menu PHP Solution 6-10: Handling a Multiple-Choice List PHP Solution 6-11: Handling a Single Check Box Chapter Review Chapter 7: Using PHP to Manage Files Checking That PHP Can Open a File Creating a Folder Outside the Server Root for Local Testing on Windows Creating a Folder Outside the Server Root for Local Testing on macOS Configuration Settings That Affect File Access Reading and Writing to Files Reading Files in a Single Operation PHP Solution 7-1: Getting the Contents of a Text File Opening and Closing Files for Read/Write Operations Reading a File with fopen() PHP Solution 7-2: Extracting Data from a CSV File Replacing Content with fopen() Appending Content with fopen() Locking a File Before Writing Preventing Overwriting an Existing File Combined Read/Write Operations with fopen() Moving the Internal Pointer Exploring the File System Inspecting a Folder with scandir() Inspecting the Contents of a Folder with FilesystemIterator Restricting File Types with the RegexIterator PHP Solution 7-3: Building a Drop-Down Menu of Files PHP Solution 7-4: Creating a Generic File Selector Accessing Remote Files Consuming News and Other RSS Feeds Using SimpleXML PHP Solution 7-5: Consuming an RSS News Feed Creating a Download Link PHP Solution 7-6: Prompting a User to Download an Image Chapter Review Chapter 8: Working with Arrays Modifying Array Elements PHP Solution 8-1: Modify Array Elements with a Loop PHP Solution 8-2: Modify Array Elements with array_walk() PHP Solution 8-3: Modify Array Elements with array_map() Merging Arrays Using the Array Union Operator Using array_merge() and array_merge_recursive() Merging Two Indexed Arrays into an Associative Array Comparing Arrays Removing Duplicate Elements PHP Solution 8-4: Joining an Array with Commas Sorting Arrays PHP Solution 8-5: Custom Sorting with the Spaceship Operator Complex Sorting with array_multisort() PHP Solution 8-6: Sorting a Multidimensional Array with array_multisort() PHP Solution 8-7: Finding All Permutations of an Array Processing Array Data PHP Solution 8-8: Building Nested Lists Automatically PHP Solution 8-9: Extracting Data from JSON Automatically Assigning Array Elements to Variables Using the extract() Function Using list() Using Array Shorthand Syntax for list() PHP Solution 8-10: Using a Generator to Process a CSV File Unpacking Arguments from an Array with the Splat Operator PHP Solution 8-11: Processing a CSV File with the Splat Operator Chapter Review Chapter 9: Uploading Files How PHP Handles File Uploads Checking Whether Your Server Supports Uploads Adding a File Upload Field to a Form Understanding the $_FILES Array Inspecting the $_FILES Array Establishing an Upload Directory Creating an Upload Folder for Local Testing on Windows Creating an Upload Folder for Local Testing on macOS Uploading Files Moving the Temporary File to the Upload Folder PHP Solution 9-1: Creating a Basic File Upload Script Creating a PHP File Upload Class PHP Solution 9-2: Creating the Basic File Upload Class Checking Upload Errors PHP Solution 9-3: Testing the Error Level, File Size, and MIME Type Changing Protected Properties PHP Solution 9-4: Allowing Different Types and Sizes to Be Uploaded PHP Solution 9-5: Renaming Files Uploading Multiple Files How the $_FILES Array Handles Multiple Files PHP Solution 9-6: Adapting the Class to Handle Multiple Uploads Using the Upload Class Points to Watch with File Uploads Chapter Review Chapter 10: Generating Thumbnail Images Checking Your Server’s Capabilities Manipulating Images Dynamically Making a Smaller Copy of an Image Getting Ready Building the Thumbnail Class PHP Solution 10-1: Getting the Image Details PHP Solution 10-2: Calculating the Thumbnail’s Dimensions Using gd Functions to Create a Scaled Copy of an Image PHP Solution 10-3: Generating the Thumbnail Image Resizing an Image Automatically on Upload Extending a Class PHP Solution 10-4: Creating the ThumbnailUpload Class Using the ThumbnailUpload Class Chapter Review Chapter 11: Pages That Remember: Simple Login and Multipage Forms What Sessions Are and How They Work Creating PHP Sessions Creating and Destroying Session Variables Destroying a Session Regenerating the Session ID The “Headers Already Sent” Error Using Sessions to Restrict Access PHP Solution 11-1: A Simple Session Example PHP Solution 11-2: Buffering the Output with ob_start() Using File-Based Authentication Making Passwords Secure PHP Solution 11-3: Creating a Password Strength Checker PHP Solution 11-4: Creating a File-Based User Registration System Checking Hashed Passwords with password_verify() PHP Solution 11-5: Building the Login Page PHP Solution 11-6: Restricting Access to a Page with a Session PHP Solution 11-7: Creating a Reusable Logout Button Keeping the Hashing Algorithm Up to Date Setting a Time Limit on Sessions PHP Solution 11-8: Ending a Session After a Period of Inactivity Passing Information Through Multipage Forms PHP Solution 11-9: Using Sessions for a Multipage Form Chapter Review Chapter 12: Getting Started with a Database MySQL or MariaDB? How a Database Stores Information How Primary Keys Work Linking Tables with Primary and Foreign Keys Breaking Down Information into Small Chunks Checkpoints for Good Database Design Using a Graphical Interface Launching phpMyAdmin Setting Up the phpsols Database MySQL Naming Rules Case Sensitivity of Names Using phpMyAdmin to Create a New Database Creating Database-Specific User Accounts Granting User Privileges Creating a Database Table Defining the Images Table Inserting Records into a Table Using phpMyAdmin to Insert Records Manually Loading the Images Records from an SQL File Creating an SQL File for Backup and Data Transfer Choosing the Right Data Type in MySQL Storing Text Storing Numbers Storing Dates and Times Storing Predefined Lists Storing Binary Data Chapter Review Chapter 13: Connecting to a Database with PHP and SQL Checking Your Remote Server Setup How PHP Communicates with a Database Connecting with the MySQL Improved Extension Connecting with PDO PHP Solution 13-1: Making a Reusable Database Connector Troubleshooting Database Connection Problems Sanitizing Text Results from a Database Querying the Database and Displaying the Results PHP Solution 13-2: Counting Records in a Result Set (MySQLi) PHP Solution 13-3: Displaying the Images Table Using MySQLi MySQLi Connection Crib Sheet PHP Solution 13-4: Counting Records in a Result Set (PDO) Counting Records with PDO in Other Databases PHP Solution 13-5: Displaying the Images Table Using PDO PDO Connection Crib Sheet Using SQL to Interact with a Database Writing SQL Queries SQL Keywords Are Case-Insensitive Whitespace Is Ignored Strings Must Be Quoted Handling Numbers Refining the Data Retrieved by a SELECT Query Selecting Specific Columns Changing the Order of Results Searching for Specific Values Searching for Text with Wildcard Characters Understanding the Danger of SQL Injection PHP Solution 13-6: Inserting an Integer from User Input into a Query Using Prepared Statements for User Input Embedding Variables in MySQLi Prepared Statements Initialize the Statement Prepare the Statement Bind Values to the Placeholders Execute the Statement Binding the Results (Optional) Store the Result (Optional) Fetch the Result Close the Statement PHP Solution 13-7: Using a MySQLi Prepared Statement in a Search Embedding Variables in PDO Prepared Statements Using Anonymous Placeholders Using Named Placeholders Preparing the Statement Binding Values to the Placeholders Executing the Statement Binding the Results (Optional) Fetching the Result PHP Solution 13-8: Using a PDO Prepared Statement in a Search PHP Solution 13-9: Debugging a PDO Prepared Statement PHP Solution 13-10: Changing Column Options Through User Input Chapter Review Chapter 14: Creating a Dynamic Photo Gallery Why Not Store Images in a Database? Planning the Gallery Converting the Gallery Elements to PHP PHP Solution 14-1: Displaying the First Image Building the Dynamic Elements Passing Information Through a Query String PHP Solution 14-2: Activating the Thumbnails Creating a Multicolumn Table PHP Solution 14-3: Looping Horizontally and Vertically Paging Through a Long Set of Records Selecting a Subset of Records PHP Solution 14-4: Displaying a Subset of Records Navigating Through Subsets of Records PHP Solution 14-5: Creating the Navigation Links Chapter Review Chapter 15: Managing Content Setting Up a Content Management System Creating the Blog Database Table Creating the Basic Insert and Update Forms Inserting New Records PHP Solution 15-1: Inserting a New Record with MySQLi PHP Solution 15-2: Inserting a New Record with PDO Linking to the Update and Delete Pages PHP Solution 15-3: Creating the Links to the Update and Delete Pages Updating Records PHP Solution 15-4: Updating a Record with MySQLi PHP Solution 15-5: Updating a Record with PDO Deleting Records Reviewing the Four Essential SQL Commands SELECT INSERT UPDATE DELETE Security and Error Messages Chapter Review Chapter 16: Formatting Text and Dates Displaying a Text Extract Extracting a Fixed Number of Characters Using the PHP substr() Function Using the LEFT() Function in an SQL Query Ending an Extract on a Complete Word Extracting the First Paragraph Displaying Paragraphs Storing Database Records as HTML Converting New Lines to Tags Creating a Function to Insert Tags Extracting Complete Sentences PHP Solution 16-1: Displaying the First Two Sentences of an Article Let’s Make a Date How MySQL Handles Dates Formatting Dates in a SELECT Query with DATE_FORMAT() PHP Solution 16-2: Formatting a MySQL Date or Timestamp Adding to and Subtracting from Dates PHP Solution 16-3: Displaying Items Updated Within the Past Week Inserting Dates into MySQL PHP Solution 16-4: Validating and Formatting Dates for MySQL Input Working with Dates in PHP Setting the Default Time Zone Creating a DateTime Object Formatting Dates in PHP Creating a DateTime Object from a Custom Format Choosing Between date() and the DateTime Class Handling Overflows with Relative Dates Using the DateTimeZone Class Adding and Subtracting Set Periods with the DateInterval Class Finding the Difference Between Two Dates with the diff() Method Calculating Recurring Dates with the DatePeriod Class Chapter Review Chapter 17: Pulling Data from Multiple Tables Understanding Table Relationships Linking an Image to an Article Altering the Structure of an Existing Table PHP Solution 17-1: Adding an Extra Column to a Table Inserting a Foreign Key in a Table PHP Solution 17-2: Adding the Image Foreign Key (MySQLi) PHP Solution 17-3: Adding the Image Foreign Key (PDO) Selecting Records from Multiple Tables PHP Solution 17-4: Building the Details Page Finding Records That Don’t Have a Matching Foreign Key Creating an Intelligent Link PHP Solution 17-5: Returning to the Same Point in a Navigation System Chapter Review Chapter 18: Managing Multiple Database Tables Maintaining Referential Integrity Support for Transactions and Foreign-key Constraints PHP Solution 18-1: Checking Whether InnoDB Is Supported Inserting Records into Multiple Tables Creating a Cross-reference Table Setting Up the Categories and Cross-Reference Tables Getting the Filename of an Uploaded Image PHP Solution 18-2: Improving the Upload Class Adapting the Insert Form to Deal with Multiple Tables PHP Solution 18-3: Adding the Category and Image Input Fields PHP Solution 18-4: Inserting Data into Multiple Tables Main Differences in the PDO Version Updating and Deleting Records in Multiple Tables Updating Records in a Cross-Reference Table PHP Solution 18-5: Adding Categories to the Update Form Treating Multiple Queries as a Block in a Transaction Using a Transaction in MySQLi Using a Transaction in PDO PHP Solution 18-6: Converting Tables to the InnoDB Storage Engine PHP Solution 18-7: Wrapping the Update Sequence in a Transaction (MySQLi) PHP Solution 18-8: Wrapping the Update Sequence in a Transaction (PDO) Preserving Referential Integrity on Deletion PHP Solution 18-9: Setting Up Foreign-Key Constraints Creating Delete Scripts with Foreign-Key Constraints Creating Delete Scripts Without Foreign-Key Constraints Chapter Review Chapter 19: Authenticating Users with a Database Choosing a Password Storage Method Using Password Hashing Creating a Table to Store Users’ Details Registering New Users in the Database PHP Solution 19-1: Creating a User Registration Form PHP Solution 19-2: Authenticating a User’s Credentials with a Database Using Secret-Key Encryption Creating the Table to Store Users’ Details Registering New Users User Authentication with Two-Way Encryption Decrypting a Password Updating User Details Where Next? Index