While deploying our old Adobe Experience Manager(AEM) code to AEM cloud service, we find some code smell issues,
ImmutableMutableMixedPackage in project build issue report. We will understand this issue here and also look how to fix this code issue from project.
Lets first understand what part of our AEM project is mutable and immutable.
Mutable
/content , /conf , /var , /etc , /oak:index , /system , /tmp , etc. are all mutable areas of AEM project, it means they can be changed at runtime.Immutable
/apps and /libs are considered immutable areas of AEM as they cannot be changed and we are not allowed to perform CUD(create, update, delete) operation at runtime. Any attempt to change an immutable area at runtime will fail. On immutable areas we can only perform the read operation.
Issue Description
In order to make our project compatible with Cloud Service deployment model, individual content packages must contain either content for the immutable areas of the repository (that is, /apps and /libs, although /libs should not and never be modified by custom code and will cause a separate violation) or the mutable area (that is, everything else), but not both. For example, a package which includes both /apps/myproject/components/text and /etc/clientlibs/myproject is not compatible with Cloud Service and will cause an issue to be reported.
When we try to edit file under /apps directory and save, aem will not allow and show error message "Could not save changes. Received 409 () for saving changes in workspace crx.default. org.apache.jackrabbit.oak.spi.state.ReadyOnlyBuilderException: This builder is read-only."
