Magento 2 : How do create Setup/InstallSchema.php?

Install Script: InstallSchema & InstallData

The InstallSchema and InstallData classes will be run during the module install.
The InstallSchema setup script in magento 2 will be use to change the database schema (create or change database table). This’s the setup script to create the m2commerce_adminlog_post table:
File: app/code/M2commerce/Adminlog/Setup/InstallSchema.php
<?php

namespace M2commerceAdminlogSetup;

class InstallSchema implements MagentoFrameworkSetupInstallSchemaInterface
{

 public function install(MagentoFrameworkSetupSchemaSetupInterface $setup, MagentoFrameworkSetupModuleContextInterface $context)
 {
  $installer = $setup;
  $installer->startSetup();
  if (!$installer->tableExists('m2commerce_adminlog_post')) {
   $table = $installer->getConnection()->newTable(
    $installer->getTable('mageplaza_helloworld_post')
   )
    ->addColumn(
     'post_id',
     MagentoFrameworkDBDdlTable::TYPE_INTEGER,
     null,
     [
      'identity' => true,
      'nullable' => false,
      'primary'  => true,
      'unsigned' => true,
     ],
     'Post ID'
    )
    ->addColumn(
     'name',
     MagentoFrameworkDBDdlTable::TYPE_TEXT,
     255,
     ['nullable => false'],
     'Post Name'
    )
    ->addColumn(
     'url_key',
     MagentoFrameworkDBDdlTable::TYPE_TEXT,
     255,
     [],
     'Post URL Key'
    )
    ->addColumn(
     'post_content',
     MagentoFrameworkDBDdlTable::TYPE_TEXT,
     '64k',
     [],
     'Post Post Content'
    )
    ->addColumn(
     'tags',
     MagentoFrameworkDBDdlTable::TYPE_TEXT,
     255,
     [],
     'Post Tags'
    )
    ->addColumn(
     'status',
     MagentoFrameworkDBDdlTable::TYPE_INTEGER,
     1,
     [],
     'Post Status'
    )
    ->addColumn(
     'featured_image',
     MagentoFrameworkDBDdlTable::TYPE_TEXT,
     255,
     [],
     'Post Featured Image'
    )
    ->addColumn(
     'created_at',
     MagentoFrameworkDBDdlTable::TYPE_TIMESTAMP,
     null,
     ['nullable' => false, 'default' => MagentoFrameworkDBDdlTable::TIMESTAMP_INIT],
     'Created At'
    )->addColumn(
     'updated_at',
     MagentoFrameworkDBDdlTable::TYPE_TIMESTAMP,
     null,
     ['nullable' => false, 'default' => MagentoFrameworkDBDdlTable::TIMESTAMP_INIT_UPDATE],
     'Updated At')
    ->setComment('Post Table');
   $installer->getConnection()->createTable($table);

   $installer->getConnection()->addIndex(
    $installer->getTable('mageplaza_helloworld_post'),
    $setup->getIdxName(
     $installer->getTable('mageplaza_helloworld_post'),
     ['name', 'url_key', 'post_content', 'tags', 'featured_image'],
     MagentoFrameworkDBAdapterAdapterInterface::INDEX_TYPE_FULLTEXT
    ),
    ['name', 'url_key', 'post_content', 'tags', 'featured_image'],
    MagentoFrameworkDBAdapterAdapterInterface::INDEX_TYPE_FULLTEXT
   );
  }
  $installer->endSetup();
 }
}
Looking into this file we will see:
The class must extend MagentoFrameworkSetupInstallSchemaInterface
The class must have install() method with 2 arguments SchemaSetupInterface and ModuleContextInterface. The SchemaSetupInterface is the setup object which provide many function to interact with database server. The ModuleContextInterface has only 1 method getVersion() which will return the current version of your module.
In the example above, we create a table named m2commerce_adminlog_post with columns: post_id, name, post_content, created_at ....
InstallData will be run after the InstallSchema class to add data to the database table.
File: app/code/M2commerce/Adminlog/Setup/InstallData.php
<?php

namespace m2commerceAdminlogSetup;

use MagentoFrameworkSetupInstallDataInterface;
use MagentoFrameworkSetupModuleContextInterface;
use MagentoFrameworkSetupModuleDataSetupInterface;

class InstallData implements InstallDataInterface
{
 protected $_postFactory;

 public function __construct(M2commerceAdminlogModelPostFactory $postFactory)
 {
  $this->_postFactory = $postFactory;
 }

 public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
 {
  $data = [
   'name'         => "How to Create SQL Setup Script in Magento 2",
   'post_content' => "In this article, we will find out how to install and upgrade sql script for module in Magento 2. When you install or upgrade a module, you may need to change the database structure or add some new data for current table. To do this, Magento 2 provide you some classes which you can do all of them.",
   'url_key'      => '/magento-2-module-development/magento-2-how-to-create-sql-setup-script.html',
   'tags'         => 'magento 2,m2commerce helloworld',
   'status'       => 1
  ];
  $post = $this->_postFactory->create();
  $post->addData($data)->save();
 }
}
This class will have the same concept as InstallSchema.

Upgrade Script: UpgradeSchema & UpgradeData

The both of this files will run when the module is installed or upgraded. This classes is difference with the Install classes because they will run every time the module upgrade. So we will need to check the attribute setup_version in module.xml at app/code/M2commerce/Adminlog/etc/ and separate the script by each version.
In this example, we will change the attrubute setup_version to 1.2.0
File: app/code/M2commerce/Adminlog/etc/module.xml
Contents would be:
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
    <module name="M2commerce_Adminlog" setup_version="1.2.0">
    </module>
</config>

Upgrade Schema:

File: app/code/M2commerce/Adminlog/Setup/UpgradeSchema.php
<?php
namespace M2commerceAdminlogSetup;

use MagentoFrameworkSetupUpgradeSchemaInterface;
use MagentoFrameworkSetupSchemaSetupInterface;
use MagentoFrameworkSetupModuleContextInterface;

class UpgradeSchema implements UpgradeSchemaInterface
{
 public function upgrade( SchemaSetupInterface $setup, ModuleContextInterface $context ) {
  $installer = $setup;

  $installer->startSetup();

  if(version_compare($context->getVersion(), '1.2.0', '<')) {
   $installer->getConnection()->addColumn(
    $installer->getTable( 'mageplaza_helloworld_post' ),
    'test',
    [
     'type' => MagentoFrameworkDBDdlTable::TYPE_DECIMAL,
     'nullable' => true,
     'length' => '12,4',
     'comment' => 'test',
     'after' => 'status'
    ]
   );
  }



  $installer->endSetup();
 }
}

In this class, we use the upgrade() method which will be run every time the module is upgraded. We also have to compare the version to add the script for each version.

Upgrade Data:

This will same with the UpgradeSchema class
File: app/code/M2commerce/Adminlog/Setup/UpgradeData.php
<?php

namespace M2commerceAdminlogSetup;

use MagentoFrameworkSetupUpgradeDataInterface;
use MagentoFrameworkSetupModuleDataSetupInterface;
use MagentoFrameworkSetupModuleContextInterface;

class UpgradeData implements UpgradeDataInterface
{
 protected $_postFactory;

 public function __construct(M2commerceAdminlogModelPostFactory $postFactory)
 {
  $this->_postFactory = $postFactory;
 }

 public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
 {
  if (version_compare($context->getVersion(), '1.2.0', '<')) {
   $data = [
    'name'         => "Magento 2 Events",
    'post_content' => "This article will talk about Events List in Magento 2. As you know, Magento 2 is using the events driven architecture which will help too much to extend the Magento functionality. We can understand this event as a kind of flag that rises when a specific situation happens. We will use an example module Mageplaza_HelloWorld to exercise this lesson.",
    'url_key'      => '/magento-2-module-development/magento-2-events.html',
    'tags'         => 'magento 2,mageplaza helloworld',
    'status'       => 1
   ];
   $post = $this->_postFactory->create();
   $post->addData($data)->save();
  }
 }
}

Recurring Script

The recurring script is a script which will be run after the module setup script every time the command line php bin/magento setup:upgrade run.
This script will be defined same as InstallSchema class but difference in name of the class. The example for this class you can see in vendor/magento/module-indexer/Setup/Recurring.php

Uninstall Script

Magento 2 provide us the uninstall module feature which will remove all of the table, data like it hadn’t installed yet. This’s the example for this class:
File: app/code/M2commerce/Adminlog/Setup/Uninstall.php
<?php
namespace MageplazaHelloWorldSetup;

use MagentoFrameworkSetupUninstallInterface;
use MagentoFrameworkSetupSchemaSetupInterface;
use MagentoFrameworkSetupModuleContextInterface;

class Uninstall implements UninstallInterface
{
 public function uninstall(SchemaSetupInterface $setup, ModuleContextInterface $context)
 {
  $installer = $setup;
  $installer->startSetup();

  $installer->getConnection()->dropTable($installer->getTable('m2commerce_adminlog_post'));

  $installer->endSetup();
 }
}
Puneet Kumar Magento Developer

Magento 2.x | Steps for create a new module

Module is a structural element of Magento 2 – the whole system is built upon modules. Typically, the first step in creating a customization is building a module.
To create a module, you have to complete the following high-level steps:
  1. Create the module folder e.g VendorName/ModuleName.
  2. Create the VendorName/ModuleName/etc/module.xml file.
  3. Create the VendorName/ModuleName/registration.php file.
  4. Run the bin/magento setup:upgrade script to install the new module.
  5. Check that the module is working.
Let’s go through each of these steps in detail.

Create the module folder

There are two possible locations for modules in Magento 2: the app/code folder and the vendor folder

Depending on how Magento 2 has been installed, core modules can either be located in the vendor/magento/magento-*folders (for composer installation) or in the app/code/Magento/ folder (for cloning GitHub).

Which of these locations should you choose for your new module?

If you build a module for a specific project, it is best to choose the app/code folder and commit to the project’s repository.
If you build an extension to be reused, it is better to use composer to create it, and put your module in the vendor/<YOUR_VENDOR>/module-something folder.
Each module name in Magento 2 consists of two parts – the vendor and the module itself. In other words, modules are grouped into vendors, so you need to define the vendor and module names. For this example, let’s name the vendor “Learning” and the module “FirstUnit”.
Let’s create the folder app/code/Learning and inside this folder place another folder: FirstUnit. If you’re using the command line, the code would be:
  1. cd to the root folder
  2. mkdir app/code/Learning
  3. mkdir app/code/Learning/FirstUnit

Make sure you have permission to create files and folders in your installation

Next, you need to create an etc/module.xml file. This file is required for the module to exist.
This file contains the following information:
  • Module name
  • Module version
  • Dependencies
Module name is defined by the folders we just created, because in Magento 2, class names must follow the folder structure. Because we created the folders Learning/FirstUnit, our module name will be Learning_FirstUnit and all classes that belong to this module will begin with LearningFirstUnit – for example: LearningFirstUnitObserverTest.
Module version indicates the current version of the database schema and data, and is used in upgrading. For example, assume you decide to modify a table’s schema in your module. How can you be sure that this change will happen on all instances where the code is deployed? Altering the database by direct SQL queries won’t work. Instead, Magento 2 has install and upgrade scripts in every module (optionally). These scripts contain commands to modify the database schema or data. To track whether to execute a script or not, Magento 2 uses module versions. Every time you implement a new database change, you implement a new version of a module and change the corresponding module.xml. Magento saves the current module’s version in a database, and if the database value and the one in the module.xml do not match, it will execute the upgrade code.
Dependencies. If one module depends on another, the module.xml file will have a special declaration that defines a list of modules that the current module depends on. For this example, we will make our module dependent on Magento_Catalog.
Using the following command-line code, create the folder app/code/Learning/FirstUnit/etc:
mkdir app/code/Learning/FirstUnit/etc

Then put the following code into it:
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<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
<module name="Learning_FirstUnit" setup_version="0.0.1"> <sequence>
<module name="Magento_Catalog"/> </sequence>
    </module>
</config>

Note that in the XML file we specified:
  • Module name: Learning_FirstUnit (based on the folders we created)
  • Version: 0.0.1 (initial version of our module)
  • Dependency: Magento_Catalog. We could have multiple dependencies. In this case, we would put <module name=”..” /> nodes under the sequence node.

Create the registration.php file

Each module must have this file, which tells Magento how to locate the module. Continuing our example, create the file app/code/Learning/FirstUnit/registration.php. Then put the following content into it:
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<?php MagentoFrameworkComponentComponentRegistrar::register(
MagentoFrameworkComponentComponentRegistrar::MODULE, 'Learning_FirstUnit',
__DIR__
);

The registration.php is a standardized file that follows the same pattern for all modules.
The only thing that varies is the module name, which in our case is Learning_FirstUnit.

Run the “setup:upgrade” command

Running this command makes your new module active, notifying Magento of its presence.
php bin/magento setup:upgrade

It should echo a large amount of output, one line of which should be Learning_FirstUnit. Verify that this line of code is there.

Check that the new module is active

So far, we haven’t added any useful code to our module – it is still empty (and therefore invisible). In order to verify that it has been recognized, check the file app/etc/config.php. It has a list of auto-generated modules that are active.
Never change this list manually!
grep Learning_FirstUnit app/etc/config.php

Employing these steps, you can successfully create a new module in Magento 2.
Puneet Kumar Magento Developer

Mysql create Database and give permission to user to access and write privilege.

Login in mysql command

mysql -u root -p

Create database command

CREATE DATABASE m2;

Grant privilege

GRANT ALL PRIVILEGES ON m2.* TO 'root'@'localhost';

Puneet Kumar Magento Developer

Tutorial: Install a LAMP Web Server with the Amazon Linux AMI

Tutorial: Install a LAMP Web Server with the Amazon Linux AMI

Open below URL and follow up step by step then you will not face any problem.
if you have any problem you can comment in this blog i will reply you within 24 hours.

Tutorial: Install a LAMP Web Server with the Amazon Linux AMI

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/install-LAMP.html

Puneet Kumar Magento Developer

Install composer on Amazon AMI running on EC2

Install composer on Amazon AMI running on EC2


$ cd ~
$ sudo curl -sS https://getcomposer.org/installer | sudo php
$ sudo mv composer.phar /usr/local/bin/composer
$ sudo ln -s /usr/local/bin/composer /usr/bin/composer

 then you can run
 $ sudo composer install

Puneet Kumar Magento Developer

What is interceptor or plugins in Magento 2?

Question : What is interceptor or plugins in Magento 2?

Plugins (Interceptors)

Basically plugin, or interceptor both are same. it is a class only which are modifies the behavior of public class functions by intercepting a functionality and running code before, after, or around that function call. This allows you to substitute or extend the behavior of original, public methods for any class or interface.

Extensions that wish to intercept and change the behavior of a public method can create a Plugin class.

This interception approach reduces conflicts among extensions that change the behavior of the same class or method. Your Plugin class implementation changes the behavior of a class function, but it does not change the class itself. Magento calls these interceptors sequentially according to a configured sort order, so they do not conflict with one another.

Plugins can not be used on following:

Final methods
Final classes
Non-public methods
Class methods (such as static methods)
__construct
Virtual types
Objects that are instantiated before MagentoFrameworkInterception is bootstrapped

Puneet Kumar Magento Developer

What is object manager in Magento 2?

ObjectManager

Object manager is Maento 2 core class a “Magento/Framework/ObjectManagerInterface”.

Object manager to avoid boilerplate code when composing objects during instantiation.

In the Magento framework, the implementation of the ObjectManagerInterface performs the duties of an object manager.

Responsibilities :

The object manager has the following responsibilities:

1. Object creation in factories and proxies.
2. Implementing the singleton pattern by returning the same shared instance of a class when requested
3. Dependency management by instantiating the preferred class when a constructor requests its interface
4. Automatically instantiating parameters in class constructors

Puneet Kumar Magento Developer

Deploy your static content on development mode for easy to develop your theme.

If your website is in developer mode, and you run bin/ magento dev:sourcetheme:
deploy, most files in this directory will be symlinked to their
sources throughout the Magento codebase. In production mode, you run
bin/ magento setup:static-content:deploy to process and copy files to
this directory.
Puneet Kumar Magento Developer

Magento 2 – How can i enable path hint or block hint by CLI command?

You can enable Block Hints with the  bin/magento dev:template-hints:enable. This only works in
Developer mode.
Puneet Kumar Magento Developer

How to switch Php version between two version on aws

First go to path of CD /use/bin directory and search here. Should be installed your Php version which one you want to switch after that you have to run below command.

sudo update-alternatives --set php /use/bin/php5.5
sudo update-alternatives --set php /use/bin/php7.3
sudo update-alternatives --set php /use/bin/php7.4
How to switch PHP version?

First go to path of CD /use/bin directory and search here. Should be installed your Php version which one you want to switch after that you have to run below command.
sudo update-alternatives –set php /use/bin/php5.5
change your php version according to you.