def execute_hooks(event_name, *args, **kwargs):
"""Execute action hooks based upon parent task state.
"""
# skip tasks that aren't part of pipeline
if not isinstance(kwargs["sender"], PipelineTask):
return
task_kwargs = deepcopy(kwargs["kwargs"]) # inception!
state = task_kwargs.get("_pipeline_chain_state", {})
if "hooks" in state:
hooks = [h for h in state["hooks"] if h.event == event_name]
if not hooks:
return []
logger.debug("task has hooks: {}".format(hooks))
context = task_kwargs["_pipeline_chain_state"]["build_context"]
callbacks = []
for hook in hooks:
try:
should_execute = safe_eval(hook.predicate, context.eval_context)
except:
should_execute = False
if should_execute:
source = kwargs["args"][0] # wtf
callbacks.append(hook.task_action.prepare(source, context))
else:
logger.debug("hook {} should not execute.".format(hook.task_action))
if len(callbacks):
logger.debug("Executing some hooks: {}".format(callbacks))
canvas = group(*callbacks)
return canvas.apply_async()
return []
def evaluate(self, expression):
"""Evaluate an expression using context.
"""
return safe_eval(expression, self.eval_context)