Practical CodeIgniter 3 (The Book + Code Samples)
Practical CodeIgniter 3
From the trenches advice and techniques for making the most out of CodeIgniter.
About the Book
Learn CodeIgniter 3 and practical solutions for crafting web applications of any size.
Whether you're a designer who's just diving into CodeIgniter and don't know where to start, a newer developer who knows some PHP and has decided to give this framework a go, or a long-time CodeIgniter developer inspired by the recent resurrection of your favorite framework and looking for fresh inspiration, this book is for you.
CodeIgniter is known as one of the simpler frameworks to get started with, in large part due to it's excellent documentation, and it's flexibility to use how you need to use it. That flexibility does come with one problem, though: How do you best work with the framework to setup workflow for you or your company. What kinds of processes can help you maintain the codebase in the long term, but not force too much complexity down your throat?
Practical CodeIgniter 3 provides answers to many of the common situations that we find ourselves needing to answer time and time again while developing our apps. Solutions to questions like:
- How can I easily theme may application
- How do I create a cronjob manager that's easy to use?
- Where do I put this code?
- Ugh! Models are so boring to write
- How do I create a protected area of the website?
- Testing CodeIgniter is hard! How can I make it work?
Planned Table of Contents
Chapter 1: Where Does This Go?
While everyone seems to have a slightly different variation of MVC definitions, this chapter will start the book off by describing how I like to think about the different file types CodeIgniter provides: models, controllers, libraries, helpers (Oh, My!) and why they work best that way.
Chapter 2: Environmental Protection Codes
This chapter will examine an all-too-underused capability of Environments. I'll show you how to set them up for maximum ease and flexibilty, and we'll discuss why they are so necessary. Especially when working in teams and using version control.
Chapter 3: Controlling Traffic
You've already learned what should and should not live in a controller, so here I'll show you how to create multiple controllers to make keep your code DRY and separate different areas of your application. We'll show you how to load them both with, and without, one of the common HMVC solutions.
Chapter 4: Showing Your Work
This chapter digs into working with views and view data. Once you understand the basics, I'll show you the way that EllisLab intended the views to work, and why it's great for performance. Next, I'll show you a simplified version of my convention-based theme system I borrowed from Rails years ago. From there, we'll explore the parser and how to integrate other parsers, like Twig or Plates.
Chapter 5: Working With Data
In this chapter we'll dig deep into using the database. Everything from basic setup to using multiple databases to separate read and write queries. We'll look at setting up a basic MY_Model to provide utility functions to increase flexibility and productivity. We'll take a look at how to validate data in the model, how to use the migration system, and even how to create our own Seeder.
Chapter 6: AJAX is Easy
I often see questions about working with AJAX in the forums, so this chapter provides the necessary knowledge to integrate AJAX into your applications with ease. We'll use the Ouput class to ensure our data types are sent correctly, build some utility methods into our My_Controller, and explore some simple jQuery setup and utilities.
Chapter 7: Working With Files
We'll look at the fabled multiple-file upload problem that plagues the forums. We'll also explore using the FTP with some real-world examples. We'll create a CSV, zip it up, and let the user download it. We'll even explore working with remote files quickly and easily.
Chapter 8: Multiple Applications
In this chapter I'll show you how to use CodeIgniter's multiple application setup to address several application needs, like separating out sections of the site for server needs or simple desires, and even how to share common code between different applications, or an API and Admin area.
Chapter 9: Security
In this chapter we'll scan through a number of topics that it's crucial you understand to help maximize the security of your application. We will make sure you understand when and why to use tools like the built in CSRF and XSS protection, how and when to filter and sanitize your data, and more.
Chapter 10: Performance
Here we examine a number of the things we can do to help increase the performance of our application, some obvious and some maybe not-so-obvious. We will cover several caching strategies and the types of caching available to you, database system tweaks for production environments, and even when and where to use CodeIgniter's autoloading features for the best performance.
Chapter 11: Fun At The Terminal
While CodeIgniter has always seemed to shun the terminal, there are times you can't get away from it. We'll explore how to work with CodeIgniter from the command line, the basics of creating CLI scripts of your own, and even how to make a simple, but flexible cronjob runner.
Chapter 12: Composing Your Application
Unless you've had your head under a rock for the last few years, you've heard of Compser and how it's shaking up the way PHP is written and shared. This chapter starts by exploring how to use it within your application to simply use some of the many high-quality packages available. We will look at codeigniter-installers and how to use it to share your CodeIgniter-specifc code. Then we'll take a look at how to use Composer to provide a completely different way of working with CodeIgniter than what you're used to: a way that is more flexible, powerful and more future proof.
About the Contributors

Technical Reviewer
Table of Contents
-
Introduction
- The Book At A Glance
- The Book At A Glance
-
1. Where Does This Go?
-
MVC - Easy as 1 2 3
- Models
- Views
- Controllers
-
So, What Goes Where?
- Helpers
- Libraries
- Third Party Code
-
Use Cases
- Simple Blog System
- Survey Generator App
- Controller Design
-
Packages
- Why Packages?
- Using Packages
-
Modules
- HMVC
- Closing
-
MVC - Easy as 1 2 3
-
2. Environmental Protection Codes
-
Determining the Environment
- Environment Setup under Apache
- Environment Setup under nginx
- Manual Setup
- Dynamic Manual Setup
- Environment Configuration
-
A Few Uses
- Configuration Differences
- Auto-Migrations
- Development Tool Routes
- Asset Compilation
- Debugging Tools
- Conclusion
-
Determining the Environment
-
3. Controlling Traffic
-
Routing Traffic
- Default (Magic) Routing
- Defining New Routes
- HTTP Verb-Based Routing
-
Controllers
- CodeIgniter’s Magic Instance
- “Global” Objects
- Remapping Methods
- MY_Controller
- Multiple Base Controllers
-
Controller Tweaks
- Flash Messages
- Global Profiler Control
- Automatic Migrations
- Cache By Default
- Outputting Plain Text
- Rendering JSON Data
- Grabbing JSON Data
- Realtime Responses
- AJAX Redirects
-
Routing Traffic
-
4. Showing Your Work
-
View Basics
- View Data
-
Constructing Pages
- Method 1: In Method
- Method 2: In View
-
A Simple Theme System
- What To Expect
- Rendering A View
- Setting View and Layout at Runtime
- Asset Methods
- Parsing View Output
-
Integrating the Twig Template Engine
- Installing Twig
- Integrating Twig
- Using the Twig Library
-
A Simple Widget System
- Overview
- The Solution
- Using The System
-
View Basics
-
5. Working With Data
-
Basic Setup
- Drivers
- Connecting Through PDO
- Should You Use PDO?
- stricton
- db_debug
- Persistant Connections
-
Basic Queries
- query()
- Query Builder
-
Basic Query Results
- result()
- result_array()
- row()
- row_array()
-
Handling Large Query Results
- unbuffered_row()
- reconnect()
- Custom Object Results
- Customizing MY_Model
-
Custom CRUD
- Class Properties
- Finding Items
- Using MY_Model
-
In-Model Validation
- Integrating Data Validation
- Using Multiple Databases
- Using Multiple Databases
- Multiple Databases In MY_Model
-
Migrations
- Creating Migrations
- Using Migrations
-
Data Seeders
- The Seeder Library
- A Seeding Controller
- Creating Seeds
-
Basic Setup
-
6. AJAX Is Easy
-
What Is AJAX, Really?
- AHAH! AJAX’s Cousin
- Server-Side vs. Client-Side Rendering
-
jQuery Setup
- Showing & Hiding the Loading Status
- Loading Page Fragments
-
Code Organization
- AJAX Controller
- Mixing AJAX & Non-AJAX Methods
- AJAX Directory
-
What Is AJAX, Really?
-
7. Working With Files
-
CodeIgniter’s File Helpers
- security_helper
- directory_helper
- file_helper
- path_helper
-
FTP and You
- Potential Uses
- Simple Database Backup
- Multiple File Uploads
-
CodeIgniter’s File Helpers
-
8. Multiple Applications
-
Configuring Applications
- Using Packages
-
Example Use Cases
- Multiple unrelated applications
- Multiple CodeIgniter versions
- Separate Application Areas
- Multiple Index files
-
Configuring Applications
-
9. Security Considerations
-
Validate Input - Filter Output
- Validate Input
- Filter Output
- Validation Tools
-
CSRF Protection
- What are CSRF Attacks?
- How to protect against them?
- CSRF and AJAX
- Expected External Forms
-
Database Security
- What Is an SQL Injection Attack?
- How to Protect Your App?
-
Logging As Security
- Database Objects
- Manual Logging
-
Validate Input - Filter Output
-
10. Performance Tips
-
The Three Quickest Performance Gains
- Opcode Caching
- Application-specific Caching
- Proper Indexing of the Database
-
Autoloading Strategies
- MY_Controllers
- Controller Constructors
- In Method
-
Caching
- Full-Page Cache
- Cache Drivers
- Russian-Doll Caching
- Cache Naming
- Database Caching
-
Database Tweaks
- Stop Saving Queries
- Don’t Return Insert ID
- Persistant Connections?
-
The Three Quickest Performance Gains
-
11. Fun at the Terminal
- Running CLI Scripts
- CLI Differences
- Restricting Access
- Exit Codes
-
Simple cronJob Runner
- Overview
- The Database
- The Controller
- Defining the Hooks
-
12. Composing Your Applications
-
Using Third-Party libraries
- Tell CodeIgniter to Use It
- Composer.json
-
Restructuring Your App
- Is Framework Dependence Bad?
- Take Command of the Application Folder
- Version Your Application
- Start Namespacing
- Use Libraries
- Inject Dependencies
- Explore Design Patterns
-
Using Third-Party libraries
- 13. Whew! We made it.
- Notes
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