The purpose of this extension is to take data from somewhere else (called the "external source") than the local TYPO3 CMS database and store it into that local database. Data from the external source is matched to local tables and fields, using information stored in the TCA with the extended syntax provided by this extension.
The extension can either fetch the data from some external source or receive data from any kind of script using the provided API. Fetching data from an external source goes through a standardized process.
Connecting to an external source is achieved using connector services (see extension svconnector), that return the fetched data to the external import in either XML format or as a PHP array. Currently, the following connectors exist:
svconnector_csv for CSV and silimar flat files
svconnector_feed for XML source files
svconnector_json for JSON source files
svconnector_sql for connecting to another database
It is quite easy to develop a custom connector, should that be needed.
The external data is mapped to one or more TYPO3 CMS tables using the extended TCA syntax. From then on the table can be synchronized with the external source. Every time a synchronization is started (either manually or according to a schedule), the connector service is called upon to fetch the data. Such tables are referred to as "synchronizable tables". This type of action is called "pulling data".
On the other hand this extension also provides an API that can be called up to pass data directly to the external import process. No connector services are used in this case. The extension is called on a need-to basis by any script that uses it. As such it is not possible to synchronize those tables from the BE module, nor to schedule their synchronization. Such tables are referred to as "non-synchronizable tables". This type of action is called "pushing data".
Note that it is perfectly possible to also push data towards synchronizable tables. The reverse is not true (non-synchronizable tables cannot pull data).
It is perfectly possible to define several import configurations for the same table, thus pulling or pushing data from various sources into a single destination.
Synchronizations can be run in preview mode.