Magento 2 migration involves migration of the following components:

  • Data Migration,
  • Extensions & Custom Code migration,
  • Themes and customizations migration

In the previous blog, we saw how data gets migrated from Magento 1 to Magento 2 and the role of a data migration tool in reducing migration efforts. Now let us explore in detail how custom code and extensions are migrated to the updated platform.

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What is Custom Code & Extension Migration all about?

Extension Migration

Extensions are crucial components that play a role in providing new features and extending the functionalities of your Magento store. It is important to remember that, Magento 1 extensions will not work on Magento 2; hence you will experience compatibility issues while integrating Magento 1 extensions into Magento 2. However, Magento 2 extensions are available on Magento Marketplace where you can download or purchase the latest versions of your favorite extensions.

Custom Code Migration

It is essential that you migrate the custom code to Magento 2 safely as there are high chances that your store would be running on custom code. In many cases, the custom code used by your Magento 1 store is compatible with Magento 2. However, Magento offers a Code Migration Toolkit which will help to port your extensions and custom code to Magento 2, significantly reducing your efforts. It should be registered that due to structural differences between the two platforms, Magento code migration may require additional efforts to make sure that the custom code successfully integrates with the Magento 2 store.

Migration from Magento 1 to Magento 2 is essential because, you want to stay updated, not outdated. Magento has stopped introducing any updates in its Magento 1 version. Also, Magento 2 provides better results, improved site performance, and drive differentiated Omni channel commerce experience.

The Scope of the Migration Procedure

The toolkit covers migration of the following aspects of the Magento code:

  • Migrate Magento 1.x module structure to the structure recognized in Magento 2
  • Migrate Magento 1.x layout XML files to the format recognized in Magento 2
  • Migrate Magento 1.x config XML files to the format recognized in Magento 2
  • Migrate the PHP code in terms of how it interacts with the Magento framework, preserving the business logic

Note that it may be necessary to regenerate the mapping files (Mapping files are used to generate lists of classes as they were transformed from Magento 1.x to Magento 2.x.) as the very first step. That is especially crucial in a case of migration between arbitrary Magento 1.x and Magento 2.x versions rather than the latest ones. It is not compulsory to do so, but implementing it greatly influences the quality of the migration results.

Understanding Migration Scripts

The Magento 2 code migration tool, Code Migration toolkit possesses the flexibility to adjust certain migration steps by configuring or skipping execution of respective migration scripts.

Module Structure Migration Script

This script does not alter the contents of any files. Instead, it simply creates the appropriate Magento 2 module directory structure and relocates the existing Magento 1.x code out there. The output of this script is utilized as inputs by other scripts in the toolkit.

Layout Migration Script

This script segregates Magento 1.x layout files into separate XML files for each layout handle and transforms their XML format to the one used in Magento 2. The script converts the contents of the handles using the mapping files and automatically tries to map and merge the mapping found in the input modules. If you feel that some mapping was not gathered, then you might need to regenerate the mapping files from a Magento installation that already has installed the modules that you are trying to convert.

The script performs the following conversion-related tasks:

  • Splits the Magento 1.x layout files into separate XML files for each layout handle
  • Replaces the root tag and adds the proper schemas
  • Transforms the block type attribute to class and converts the name to Magento 2.x class
  • Converts to where needed removing the class on the container
  • Converts<reference> to <referenceBlock> or <referenceContainer>
  • Converts format of action arguments
  • Converts the translation labels as attributes

Config Migration Script

This script splits Magento 1.x config XML files and converts them to Magento 2.x XML format.

PHP Code Migration Script

This script converts most of the PHP code in the target directory to the Magento 2.x requirements.
Prerequisite: Although you can run this script without first completing steps one and two, it is however recommended to first run steps one and two for optimal accuracy. The script does performs conversion-related tasks like adding PHP 5.3+ namespaces used in Magento 2.x framework; Converts class name and full qualifier name for extends and implements; Replaces all references to a Magento 1.x class with the name qualifier for the Magento 2.x class etc.


The migration of Magento modules is the main focus of the toolkit. Magento themes are out of the scope of the toolkit at present. The toolkit can significantly lessen the work involved in the code migration

Just like an upgrade between 1.x versions (for example, from v1.12 to v1.14), the level of effort to migrate from Magento 1 to Magento 2 depends upon how you have built your site and its level of customization.

Learn more about our Magento expertise here Magento Miniseries.

Aspire Systems is a Magento Business Solution Partner. Get in touch with our in-house experts to discuss Migration to Magento 2.0.