Slideshow Transcript

1. Slide 1: Introduction to CodeIgniter Steve Webb Refresh OKC 17 Jun 2008
2. Slide 2: What is CodeIgniter?  CodeIgniter is a lightweight web application framework written in PHP that adopts the model-view-controller approach to development
3. Slide 3: Why use a framework?  Web application frameworks provide basic building blocks needed by most applications – Database connections – Business logic – Form handling  Separation of concerns  Easier testing (unit tests)
4. Slide 4: Why use CodeIgniter?  Feature rich  Lightweight  Open source  Well-supported by an active community  Excellent “by example” documentation  Easy to configure  Supports multiple databases
5. Slide 5: Why use CodeIgniter?  In short, CodeIgniter is nice because it does what it needs to do and then gets out of the way.
6. Slide 6: Model-View-Controller  Model – representation of the data  View – rendering of the data suitable for interaction with the user  Controller – the “traffic cop” that passes model data to the views and vice versa  This separation of concerns allows for greater flexibility, reuse of code, and overall preservation of the developer’s sanity
7. Slide 7: Controller  A class containing one or more related methods (custom PHP functions)  Typical uses: – Request a set of data from the model by sending arguments – Send a payload of data to a view (web page) – Receive a data payload from a view – Apply business logic to make decisions – Pass data to the model for inclusion in a database
8. Slide 8: View  Code that displays information to the user  Views can be: – Web pages with PHP code snippets inserted – Web pages with forms to gather user input – Other output (CSV, PDF, etc.)
9. Slide 9: Model  A class containing one or more related methods (custom PHP functions)  Typical uses: – Create – Read – Update – Delete
10. Slide 10: CodeIgniter Classes  CI’s built-in classes contain the basic functionality that are frequently used by web applications  The most-used classes are: – Database – Input – Loader – URI – Validation
11. Slide 11: Database Class  Generates queries using the Active Record Pattern  Automatic escaping of input values  Provides method “chaining” for easy query building  $this->db->where(‘name’,$name);
12. Slide 12: Input Class  Pre-processes user input (prevents common cross-site scripting techniques)  Provides access to user input and other data: – Form fields (POST) – Cookies – Server variables  $this->input->post(‘fieldname’);
13. Slide 13: Loader Class  Makes various resources available: – Databases – Views – Helpers – Plugins  $this->load->view(‘viewname’);
14. Slide 14: URI Class  Provides access to specific parts of the URI string  Useful for building RESTful URIs  $this->uri->segment(n);
15. Slide 15: Validation Class  Helps validate user form input – Required fields – Required string formatting (length, regexp)  Enables success and failure messages on form submittal  Enables re-population of form fields after form submittal
16. Slide 16: Other Classes  Benchmarking  Language  Calendaring (internationalization)  Email  Output  Encryption  Pagination  File uploading  Session  FTP  Trackback  HTML Table  Unit testing  Image Manipulation  XML-RPC  Zip encoding
17. Slide 17: Helpers and Plugins  CodeIgniter comes with a wide array of “helper” functions that add convenience to applications and provide ease of reuse.  $this->load->helper(‘helper_name’);  CodeIgniter also allows for the use of custom add-on functions called “plugins”.  $this->load->plugin(‘plugin_name’);
18. Slide 18: My First CI Application 1. Unzip CI zip file into application folder on web server 2. [optional] For “pretty URLs”, add .htaccess file and enable mod_rewrite in Apache 3. Configure database in CI’s <config.php> 4. Write controller (or modify existing) 5. Write view (or modify existing) 6. Write model
19. Slide 19: Demo