Python-Design-Patterns mediator
mediator Model
Python-Design-Patterns mediator
# file: 'mediator.py'
#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
http://web.archive.org/web/20120309135549/http://dpip.testingperspective.com/?p=28
*TL;DR80
Encapsulates how a set of objects interact.
"""
import random
import time
class TC:
def __init__(self):
self._tm = None
self._bProblem = 0
def setup(self):
print("Setting up the Test")
time.sleep(0.1)
self._tm.prepareReporting()
def execute(self):
if not self._bProblem:
print("Executing the test")
time.sleep(0.1)
else:
print("Problem in setup. Test not executed.")
def tearDown(self):
if not self._bProblem:
print("Tearing down")
time.sleep(0.1)
self._tm.publishReport()
else:
print("Test not executed. No tear down required.")
def setTM(self, tm):
self._tm = tm
def setProblem(self, value):
self._bProblem = value
class Reporter:
def __init__(self):
self._tm = None
def prepare(self):
print("Reporter Class is preparing to report the results")
time.sleep(0.1)
def report(self):
print("Reporting the results of Test")
time.sleep(0.1)
def setTM(self, tm):
self._tm = tm
class DB:
def __init__(self):
self._tm = None
def insert(self):
print("Inserting the execution begin status in the Database")
time.sleep(0.1)
# Following code is to simulate a communication from DB to TC
if random.randrange(1, 4) == 3:
return -1
def update(self):
print("Updating the test results in Database")
time.sleep(0.1)
def setTM(self, tm):
self._tm = tm
class TestManager:
def __init__(self):
self._reporter = None
self._db = None
self._tc = None
def prepareReporting(self):
rvalue = self._db.insert()
if rvalue == -1:
self._tc.setProblem(1)
self._reporter.prepare()
def setReporter(self, reporter):
self._reporter = reporter
def setDB(self, db):
self._db = db
def publishReport(self):
self._db.update()
self._reporter.report()
def setTC(self, tc):
self._tc = tc
if __name__ == '__main__':
reporter = Reporter()
db = DB()
tm = TestManager()
tm.setReporter(reporter)
tm.setDB(db)
reporter.setTM(tm)
db.setTM(tm)
# For simplification we are looping on the same test.
# Practically, it could be about various unique test classes and their
# objects
for i in range(3):
tc = TC()
tc.setTM(tm)
tm.setTC(tc)
tc.setup()
tc.execute()
tc.tearDown()
### OUTPUT ###
# Setting up the Test
# Inserting the execution begin status in the Database
# Executing the test
# Tearing down
# Updating the test results in Database
# Reporting the results of Test
# Setting up the Test
# Inserting the execution begin status in the Database
# Reporter Class is preparing to report the results
# Problem in setup. Test not executed.
# Test not executed. No tear down required.
# Setting up the Test
# Inserting the execution begin status in the Database
# Executing the test
# Tearing down
# Updating the test results in Database
# Reporting the results of Test
mediator.py
