Node

Node is callable thing .In python world ,we have three callable things ,

  • function
  • function object. class with override `__call__`
  • lambada

Major work of user of Botflow shouble be writing core logic function, for parsing, mapping,calculating , aggregating. It is the main purpose of Botflow desing.

Pass into Node:

Node must have only one parameter. the pass in value is from upflow node return value.

Return from Node:

Node can return anything . list ,generator,raw value,tuple .

Attention

  • list will be unpacked into separate item . tuple will not be unpacked.
  • generator will be iterated by bot. so you can return a infinite generator to simulate a stream flow it is interested to test.
  • raw will put into queue.

How to handle Excpetion:

Exception behavior will act according to `config.Exception_policy = config.Exception_raise ` setting.

Exception_default:
 default exception policy is raise
Exception_raise:
 raise exception
Exception_ignore:
 ignore exception. exception raised from node will be suppressed.
Exception_retry:
 the value will put in input-queue after some delay.
Exception_pipein:
 the exception tread as returen value ,put in output queue. it will be usefull in blockedjoin route scenarios.

Timer

It will send a message in the pipe by timer param. delay, max_time until some finished

`Timer(self, delay=1, max_time=None, until=None)`

dealy:the delay between every count
max_time:will stop when reach the max count time.
until:the function ref. Timer will count until function return True.

HttpLoader

Get a url and return the HTTP response

timeout:default timeout=20 .

can be call by string (url), and Httprequest.

HttpResponse

json:return a json object
text:get text body of the httpresponse
xml:get lxml object
css:get css object
head:
body:
url:
proxy:

AioFile

for file I/O.

SpeedLimit

limit the stream speed limit

Delay

delay in special second.

Zip

Wait for all branched to finish and merged the result into a tuple.

Filter

Drop data from pipe if it does not match some condition