This article may seems to you extra, as the topic has been covered in many places. There are many other and preferred ways to do this. The reason why I chose the topic, is to show what are the difficulties I have faced while migrating one project. So…hang tight: From Symfony 3.x, the symfony installaer came into light. So to install a Symfony 3.4 version you can opt for any 02 paths: 1. Using installer: Grab Symfony installer

https://github.com/symfony/symfony-installer c:\bin> php -r “file_put_contents(‘symfony’, file_get_contents(‘https://symfony.com/installer’));” c:\bin> (echo @ECHO OFF & echo php “%~dp0symfony” %*) > symfony.bat

Install Symfony 3.4 cd to htdocs(I used xampp) and run

symfony new your_project_name 3.4

2. Using composer:

composer create-project symfony/framework-standard-edition your_project_name/ “3.4.*”

Now once to change directory to your_project_name, first thing you have to do is to create bundle. You might have installed custom bundle in your Symfony 2.x phase:

php bin/console generate:bundle –namespace=YourNameSpace/YourBundle

This will ask several inputs, only value to provide is configuration format which should be yml (you may need to try twice) Now you will face and autoload issue: It will not able to change autoload and the message below will be displayed: The command was not able to configure everything automatically. Now open composer.json and locate the autoload section: Change it to “psr-4”: { “”: “src/” }, Which will looks like: Now run composer update, see what happened in following figure: Acquire dependent bundles Now we must acquire all dependent bundles, need to run

composer require sonata-project/doctrine-orm-admin-bundle

and so on….. While configure, you will notice many deprecation issue. It depends on bundle configurations. For an example: To remove deprecation, found this https://stackoverflow.com/questions/47698006/symfony-3-4-refreshing-a-deauthenticated-user-is-deprecated, security.yml should looks like:

main: logout_on_user_change: true anonymous: ~

Import & configure DB Now it’s time to import database: Run

php bin/console doctrine:database:create –connection=default

This will create database, now import the existing database into newly created one Now copy doctrine folder and paste into src/yourbundle/Resources/config folder run

php bin/console doctrine:generate:entities YourNameSpace/YourBundle php bin/console doctrine:schema:update –force

Database is configured, now setup vhost and try in browser (add app_dev.php in .htaccess and comment line #13-19 in app_dev.php) Now copy all folders from bundle, except DependencyInjection, Entity, Resources etc. Move views and public assets Copy src/Bundle/Resources/public directory to same location in Symfony 3.4 and run below command

php bin/console assets:install web php bin/console cache:clear –env=dev

Copy existing src/Bundle/Resources/views files to app/Resources/views Remove all YourNameSpaceYourBundle::” bundle scope from twigs as all templates moved to app/Resources from src/Bundle namespace That’s all as of now. Stay tuned !!!