Elastic Path Core Commerce uses a lightweight plug-in architecture based on Spring functionality. This architecture allows you to create plug-ins that work with existing Core Commerce modules, without needing to make any changes to the core application code or configuration files.

The Spring contexts of Elastic Path applications use wildcards to include Spring configuration files from well-known classpath locations. There are two patterns:

The first pattern is for the plug-ins to be included from an extensions module. For example, the elastic-path-servlet.xml file in the extensions/integration module contains:

<import resource="classpath*:META-INF/elasticpath/conf/spring/plugin.xml"/commerce-legacy/>
<import resource="classpath*:META-INF/conf/ep-core-plugin.xml"/commerce-legacy/>

The second pattern is for the extensions to be included from a commerce-engine module. For example the import-export-context.xml file in the ep-importexport module contains:

<import resource="classpath*:META-INF/conf/ep-core-plugin.xml"/commerce-legacy/>
<import resource="classpath*:META-INF/conf/ep-importexport-plugin.xml" />

These statements cause the application to examine all JARs on the classpath and automatically include any copies of these files.

There are three separate plug-in conventions in these examples: