api.py

@resource_op
def query_workflow_definitions(filters=None, deep_copy=False, params=None,
                               ignore_deleted=True, session=None, agent=None, return_dict=True):
    filters = filters or {}

    # Tags
    q = session.query(Tag)
    tags = q.all()

    # Workflows
    q = session.query(Workflow)
    ws = q.all()

    # Get the WorkflowDefinitions
    q = session.query(WorkflowDefinition)
    if ignore_deleted:
        q = q.filter(WorkflowDefinition.archived == False)

    q = q.options(
        # lazyload('instances'),
        joinedload(WorkflowDefinition.workflow_protocols)   # joinedload faster
        .joinedload(WorkflowProtocol.protocol)   # joinedload faster
        .subqueryload(Protocol.head.of_type(ProtocolDefinition)),
        joinedload(WorkflowDefinition.step_lims_vars)   # joinedload faster
        .subqueryload(StepLimsVar.variable),
        joinedload('workflow_sample_types')
        .subqueryload('sample_type')
        .subqueryload('head'),
    )

    # Load Workflows/Protocols
    if not return_dict:
        return q.all()

    wf_dicts = [wf.as_dict(deep_copy, params) for wf in q.all()]
    return wf_dicts