gustafn
committed
on 11 Aug 17
Add Feature: Shared Workflow Definitions

Background: so far, xowf stored workflow definitions in the workflow
context, which is generated f… Show more
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.

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