def view_html(request):
"""This function expects to receive a context object, having
a pipeline and an execution as attributes.
Each pipeline element is either a resource or an action.
While iterating through the pipeline, each time a resource is found
it is pushed into the execution's stack. If an action is found it
pops its parameters from the execution stack, optionally pushing
its results on to the top of the stack.
"""
# FIXME
## import pdb; pdb.set_trace()
uri = request.META['REQUEST_URI'][14:] #9: strip-off '/web/actionlet'
# preserve pipeline history
# this may be needed is some action or resource
# needs to look into the past
pipeline = PipelineQueue(uri)
# An Executor instance is needed to hold the
# execution stack and index to which is the current
# pipeline's stage
config = pyisis.config.config
# FIXME
execution = Execution([Engine.collection])
# prepare context object for actionlets
context = StringIO()
context.execution = execution
context.pipeline = pipeline
context.META = request.META
params = None
for index, (stage, params) in enumerate(pipeline):
if stage.startswith(ACTION_SEP):
# this is an action. Call it!
action = getattr(action_registry, stage[1:])
action(context, params)
else:
# This is a resource. Load it!
# So far a resource string is a key for
# a value inside the resource container object
# placed at the top of the stack
resource_container = execution.pop()
key = stage
new_resource = resource_container[key]
execution.append(new_resource)
execution.stage_index += 1
# If something is left at the top of the stack
# it will be added to the HTTP response
try:
resource = context.execution.pop()
context.write(unicode(resource).encode(config.OUTPUT_ENCODING))
# Handle encoding
except IndexError:
pass
return render_to_response('actionlet.html', {
'title': 'ISIS NBP Cell',
'verbatim': context.getvalue()
},
context_instance=RequestContext(request))
