Application Structure

After installation, if you take a look at the files and folders in the tutorial application, you’ll see the following basic application structure:

  • app/
    • config/
    • src/
    • view/
  • database/
    • migrations/
    • seeds/
  • public/
  • script/

The app/ folder contains the main set of folders and files that make the application work. The database/ folder contains the SQLite database file. The public/ folder is the web document root that contains the main index file. And the script/ folder contains the main script to execute the CLI side of the application.

A more expanded version of an Pop application structure may look like this:

  • app/
    • config/
      • forms/ (Form and form field configurations)
      • routes/ (Route configurations)
        • http.php
        • console.php
      • app.http.php
      • app.console.php
    • src/ (Main application source files)
      • Controller/
      • Form/
      • Model/
      • Table/
      • Module.php
    • view/ (Application view scripts)
  • data/ (Application data store for logs, files, etc.)
    • logs/
    • tmp/
  • database/ (Database seed and migration files)
    • migrations/
    • seeds/ - app.sql
  • logs/ (Web server log files)
  • public/ (Web server document root)
  • script/ (CLI-based application scripts)
  • tests/ (Application tests)
  • vendor/ (3rd-party vendor packages)

This structure isn’t necessarily set in stone, but it follows a typical structure that one might expect to see within a PHP application.

Application Module

Application development with Pop PHP promotes modular development, meaning that it aides creating smaller “mini-application” modules that can be registered with the main application object. If you look inside the Tutorial\Module class, you see the lines:

$this->application->on('app.init', function($application){

Once those lines of code are executed upon the app.init event trigger, the database becomes available to the rest of the application. Furthermore, you’ll see a CLI specific header and footer that is only triggered if the environment is on the console.

Front Controllers

You can see the main front controllers in the public/ and scripts/ folders: public/index.php and script/app respectively. Looking into each of those, you can see that the main Pop\Application object is created and wired up, with the Tutorial\Module object being registered with the main application object so that it will be wired up and function correctly. We will look at these more in-depth in the next sections.

Application Classes

Beyond the front controllers and the main module class, there are classes for the following, each in its own folder:

  • controllers - app/src/Controller
  • forms - app/src/Form
  • models - app/src/Model
  • tables - app/src/Table

There is a specific controller for each of the two environments, web and console. There is a single form for collecting, validating and submitting a post comment. That form class is only used in the web environment as it is a web form. And the model and table classes are used in both environments, as they serve as the gateway between the application and its data.