CLASSES

1. Encaplusation: Building of data and behaviours, that are similar, together ex: Bike class can has color, year, model number, clean and ride functions
2. Abstraction: Access to something complex without knowing the inner workings we will just call clean() method and bike is clean However, beneath the hood clean function is doing lots of steps to clean the bike (fill the bucket)
3. Inheritence: create hierarchical relationships between items Student, Mechanic, Doctor are all People (they below to the people class) they all have fucntions walk() sleep() run(), variables: height, name, age But Mechanic class already inherits generic People class and species new specific methods
4. Polymorphism Multiple functions of the same name doing something specific Gardnener works differently from Doctor we can add a function of work to each of our people based on the type of person (which work they do) many forms of the same work() method

USEFUL PHP COMMANDS

var_dump($GLOBALS).PHP_EOL; #prints global variables defned somwhere in the php script (functions can access them) var_dump($_SERVER).PHP_EOL; # prints the server infor like http_host var_dump($_REQUEST).PHP_EOL; # print all requests info (get and post, headers) var_dump($_POST).PHP_EOL; # only print the body of the request htmlspecialchars($_GET["q"]) # converts special html characters into the associated entities ex: <> " & for safety (for when we try to read what was in the get or post request so we do not run javascript code accidentally) htmlspecialchars($_GET["q"], ENT_QUOTES) # also does the single quote htmlspecialchars($_GET["q"] ?? "", ENT_QUOTES) # check if $_GET["q"] exists or use empty string

HOW TO RUN PHP SERVER LOCALLY WITH JUST PHP:

php -S localhost:8080 above is a command line to run php index file on a local server (not good for prod tho, use nginx) by default it accesses index.php but you can access individual files with

localhost:8080/network_requests.php tail -f logs/query.log to see the logs stream in

PHP INI FILE TO SEE THE PHP SETTINGS

php -r "phpinfo();" | grep php.ini output: Loaded Configuration File => /opt/homebrew/etc/php/8.2/php.ini

WHERE DOES PHP STORE SESSION FILES (SO WE MANAGE STATE OF A SESSION BECAUSE PHP ITSELF IS STATELESS)

We need to store sessions state somewhere outside of the php code since php is stateless. Thus, we just give user browser a cookie which has an actual file name stored in that cookie value While in our local computer we store this file locally which contains an actuall session info (refer to course2/login.php) For example, this file can contain if user isAdmin, cookie tells php which file to look for. Thus, actual session info is stored on the server itself, not in a cookie file (treat cookie as a pointer).

To find file location: php -r 'echo "PHP Sessions PATH: ".((session_save_path()) ? session_save_path():sys_get_temp_dir() ).PHP_EOL;'

example of a PHP session file in /var/folders/j8/y8s9d0gx72jd3w5dg05xfzwr0000gp/T folder: sess_r8n2garf6fgj1bcsfjkirbi2de

The cookie pointing to this file will contain the value of: r8n2garf6fgj1bcsfjkirbi2de

The context of the file: username|s:5:"test2";isAdmin|s:1:"1";%

The way how it works in code:

session_start();
$_SESSION['username'] = $row->name;
$_SESSION['isAdmin'] = $row->isAdmin;

How to Start PHPMyAdmin Server to work with PHP and MySQL

1. Navigate to phpMyAdmin folder (where you downloaded from phpadmin) cd /Users/amirganiev/Documents/learning/php/phpMyAdmin-5.2.1-all-languages

2. Start the php server in the folder php -S localhost:8090

3. config.sample.inc.php contains important configuration for phpMyAdmin. Such as host path (default is localhost) You can configure this file and save to config.inc.php

HOW TO WORK WITH MYSQL LOCALLY:

Installation process:

1. Now simply run the below command in your terminal $ brew install mysql

2. Start the MySQL service $ brew services start mysql

3. Set root MySQL password $ mysqladmin -u root password 'secretpassword'

4. Access MySQL on mac , THE PASSWORWID IS 'secretpassword' $ mysql -u root -p

Command will ask the password you just set in the previous step.

Things to remember Stop MySQL service on Mac start

If you don't want MySQL service to start every time you start your mac then run the below command

$ brew services stop mysql This will stop the MySQL service from running in the background.

Start MySQL service

You can always run the below command to start the MySQL server on mac and it will not start on the next computer restart

$ mysql.server start Stop MySQL service

If you want to immediately stop the MySQL service then run the below command

$ mysql.server stop

#HOW TO WORK WITH COMPOSER https://weaintplastic.github.io/web-development-field-guide/Development/Frontend_Development/Setting_up_your_project/Setup_Dependency_Managers/Composer/Initialize_Composer_on_a_new_Project.html

Use your command line and navigate to the root folder of your project and enter

$ composer init After that you'll get some questions ask in order to generate composers's configuration file `composer.json``

Package name (<vendor>/<name>): vendor/name
Description []: // leave empty
Author: Roland Loesslein <info@weaintplastic.com>
Minimum Stability []: // leave empty if not specified
License []: // leave empty if not specified
Would you like to define your dependencies (require) interactively [yes]? no
Would you like to define your dev dependencies (require-dev) interactively [yes]? no
Do you confirm generation [yes]? yes

To specify a directory where the composer libraries are saved to, please open up your composer.jsonand add the following line. I just tend to rename the default vendor-dir vendor to composer_vendor to follow the naming scheme that is used by Bower and NPM.

"config": {
    "vendor-dir": "composer_vendor"
}

You are now ready to install your third party libraries, frameworks and such using composer. Therefore you use your command line and the command composer require

$ composer require erusev/parsedown:~1.0

The installed packages are saved in your projects root folder named composer_vendor. While your frontend dependencies are usually not needed during runtimem but compiled for shipping, your composer dependencies are most likely used during runtime. Make sure to NOT exclude your composer_vendor folder from being tracked by git.

SESSIONS

There are 4 ways to confgure a sessions:

1. .htaccess is used to set session configuration for php for the whole directory (which is what we did while learning) (medium global)
2. phpini file for the running instance of php in the server (most global)
3. Apache configuration file, httpd.conf for running instance of Apache (most global)
4. ini_set() for one php file (the least global)

You can use phpinfo.php script located in the directory of interest to see what is the session configuration for this directory in the session section of the information displayed. You can also view the master configuration for the session that was overwritten by this directory configuration (for example .httaccess overwrite of the master configs)