Architecture Patterns
Application Type
Traditional Web

Hi, how do i visualize the difference between extension pattern (library module) and extension core service pattern(core business module)?

my understanding as below.

library module extension pattern:

when data is in external system(like ERP) then create a service in library module that will interact with the ERP and allow this library service to be consumed by the service in core business layer. this is called extension pattern. if further abstraction required then extension connector pattern can be designed.

core business module entity core service pattern.

here, core entity is designed within the core business module and a service is written to access/update the data from/into the entity.   

external core service pattern.

here, data is in external system(ERP). service is in core module which calls the service in library module which in turn interacts with ERP and fetches data. 

so, my question is when there is no entity then shouldn't that be called (designed) as extension pattern?

apologies - if my understanding and question is incorrect. 

Hi Megavarnan Govindaswamy

Check the link... I think here you can understand better about Outsystems architecture.


Gonçalo Almeida

Hi Goncalo,

Good documentation and goo sugestion.

Just to add the related videos here (can be cool to someone with the same questions):

Best regards,

Ricardo M Pereira

sure. thanks for this input Mr. Goncalo Almeida.

Understand the below.

important aspect, i understand as why extension core service pattern, is bringing data(in full, or partial) from external system into the core entity module and then leverage cache and/or sync concepts.

this helps improve performance.

thanks again.

Glad I could help.

If you are ok with the answer please mark it as "solution" in order to close this thread.


Gonçalo Almeida

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