Concept
Overview
Shopware Migration Assistant was built with simple but powerful concepts in mind. These enable you to extend the plugin in various ways and migrate data into the Shopware 6 environment. You should have a basic understanding of how to use the migration plugin and its core features before extending it yourself, as this documentation will not explain the usage of the plugin.
We will provide you with a basic introduction to the concepts and structure right here in this chapter. Take a look at the last headline (Extension points) to find out more about the various ways to extend this plugin.
Profile and connections
Users of the plugin can create connections to different source systems. A connection is used to allow multiple migrations from the same source and update the right data (mapping). Connections require a specific profile indicating the type of source system. Users can, for example, create a connection to a Shopware shop using the Shopware 5.5 profile. Developers can create their own profiles from scratch, connect to different source systems, or just build and extend existing ones.
For more details, look at Profile and Connection.
DataSelection and dataSet
These are the fundamental data structures for defining what to migrate. Each DataSet
represents an entity, for example, a database table. Each DataSelection
represents an orderly group of DataSets
. For more information, refer to the articles on DataSelection and DataSet.
Migration context
This data structure provides all the necessary data for the migration. For more details, refer to the Migration Context.
Premapping
Because the structure of the source system does not always match the structure of the target system, the user may need to map the old structure to the new one. For example, in Shopware 5, we have default salutations like Mr.
, but the user can also create custom ones. In Shopware 6, there are default salutations like Mr.and the user can also create custom ones. So the salutation
Mr.from Shopware 5 must be mapped to Shopware 6
Mr.`. In this default case, the mapping can be achieved automatically, but customized salutations will most likely have to be mapped manually. The premapping will be written into the mapping table to associate the old identifier with the new one.
You can look at Premapping section for more details.
Gateway and reader
Users will have to specify a gateway for the connection. The gateway defines the way of communicating with the source system. Behind the user interface, we use Reader
objects to read the data from the source system. For the shopware55
profile, we have the api
gateway, which communicates via http/s with the source system, and the local
gateway, which communicates directly with the source system's database. Thus both systems must be on the same server to successfully use the local
gateway.
To use the ShopwareApiGateway
, you must download the Shopware Connector plugin for your Shopware 5.
For more details, look at the Gateway and Reader article.
Converter, mapping, and deltas
Data gathered by Reader
objects is transferred to Converter
objects that put the data in a format Shopware 6 is able to work with. Simultaneously entries in the underlying mapping table are inserted to map the old identifiers to the new ones for future migrations (Have a look at the MappingService
for that). The mapping is saved for the current connection. Converted data will be removed after the migration, and the mapping will stay persistent. Also, a checksum is saved to the mapping to identify and skip the same source data (data has not been changed since the last migration).
You can find out more about them in the Convert and Mapping section of this guide.
Logging
During any migration, especially during the data conversion, there will possibly be errors that should be logged. The users can see these errors and these should be as helpful as possible.
For more information, have a look at the Logging section.
Writer
The Writer
objects will receive the converted data and write it to Shopware 6. There is no special magic here; you don't need to worry about error handling because the migration assistant takes care of it.
To learn more about them, take a look at Writer section.
Media processing
During a typical migration, we download the media files from the source system to Shopware 6. This is the last processing step in the migration and may be done differently for other gateways. For example, the local
gateway will copy and rename the files directly in the local filesystem.
You can look at Media Processing article for more details.
After migration
All fetched data will be deleted after finishing or aborting a migration run, but the mapping of the identifiers will stay.
The migration procedure
The following bullet points will give you a general overview of what happens during a common migration.
- The user selects/creates a connection (with a profile and gateway specified).
- The user selects some of the available data (
DataSelections
). - Premapping check/execution: The user maps data from the source system to the current system (these decisions are stored with the connection).
- Fetch data for every
DataSet
in every selectedDataSelection
(mapping is used to store/use the identifiers from the source system). 4.1 The correspondingReader
reads the data. 4.2 The correspondingConverter
converts the data. - Write data for every
DataSet
in every selectedDataSelection
. 5.1 The correspondingWriter
writes the data. - Process media, if necessary, for example, to download/copy images . 6.1 Data in the
swag_migration_media_file
table will be downloaded/copied. 6.2 Files are assigned to media objects in Shopware 6. - Finish migration to clean up.
These steps can be done multiple times. Each migration is called a Run
/MigrationRun
and will be saved to inform the users about any errors that occurred (in the form of a detailed history).
Extension points
The recommended way to migrate plugin data from a source system is to extend that profile by a new DataSelection
. It is also possible to create a new profile in case a migration from a different shop/source system is sought.
Take a look at the following HowTos for your scenario to get a step-by-step tutorial:
- Extending a Shopware Migration Profile: Migrating your first basic plugin data (via local gateway).
- Extending the Migration Connector: Add API support for your migration.
- Decorating a Shopware Migration Assistant Converter: Implement a premapping and change the behavior of an existing converter.
- Creating a New Migration Profile: Create a new profile from scratch to support a third-party source system (other than Shopware).