Add Feature: Shared Workflow Definitions
Background: so far, xowf stored workflow definitions in the workflow
context, which is generated for every instantiated workflow instance
due to the needs of the State Pattern. While the old approach works
perfectly fine, when pre request only one or a few workflow instances
are created, but is inefficient, when e.g. 100 or more instances of
the workflow definition are created.
Now, the instances can share the definition, which is shared based on
the revision_id of the workflow FormPage.
OLD: obj <-> obj::wf_ctx
NEW: obj <-> obj::wf_ctx <(n)----> wf_definition
OLD scenario:
- the wf_definition was part of the context (no distinction)
- navigation from wf_ctx (and wf_definition) to object was possible
via "info parent"
NEW scenario:
- the wf_definition is separate
- one wf_definition can be used for multiple wf_ctx
- new methods are required instead of "info parent"
to navigate between these cooperating objects
* xowf::WorkflowPage.wf_context
* xowf::WorkflowConstruct.wf_context
* xowf::Context.wf_container
The navigation from a WorkflowConstruct (e.g. State) to the wf_ctx
is slow and fragile if not following usual programming conventions
and should e avoided (the methods of these constructs have the obj
passed in, so this path should not be necessary in most situations)
- as long the contents of the wf_container is constant, it can be
shared in the per-thread cache.
For now, the new feature is turned off by default via variable
::xowf::sharedWorkflowDefinition, but this will change in the future.