'''
Output various aspects of topic tree to string or file.
:copyright: Copyright 2006-2009 by Oliver Schoenborn, all rights reserved.
:license: BSD, see LICENSE.txt for details.
'''
from textwrap import TextWrapper
from topictreevisitor import ITopicTreeVisitor
class TopicTreePrinter(ITopicTreeVisitor):
'''
Example topic tree visitor that prints a prettified representation
of topic tree by doing a depth-first traversal of topic tree and
print information at each (topic) node of tree. Extra info to be
printed is specified via the 'extra' kwarg. Its value must be a
list of characters, the order determines output order:
- D: print description of topic
- A: print topic kwargs and their description
- a: print kwarg names only
- L: print listeners currently subscribed to topic
E.g. TopicTreePrinter(extra='LaDA') would print, for each topic,
the list of subscribed listeners, the topic's list of kwargs, the
topic description, and the description for each kwarg,
>>> Topic "delTopic"
>> Listeners:
> listener1_2880 (from yourModule import
> listener2_3450 (from yourModule import
>> Names of Message arguments:
> arg1
> arg2
>> Description: whenever a topic is deleted
>> Descriptions of Message arguments:
> arg1: (required) its description
> arg2: some other description
'''
allowedExtras = frozenset('DAaL') # must NOT change
ALL_TOPICS_NAME = 'ALL_TOPICS' # output for name of 'all topics' topic
def __init__(self, extra=None, width=70, indentStep=4,
bulletTopic='\\--', bulletTopicItem='|==', bulletTopicArg='-', fileObj=None):
'''Topic tree printer will print listeners for each topic only
if printListeners is True. The width will be used to limit
the width of text output, while indentStep is the number of
spaces added each time the text is indented further. The
three bullet parameters define the strings used for each
item (topic, topic items, and kwargs). '''
self.__contentMeth = dict(
D = self.__printTopicDescription,
A = self.__printTopicArgsAll,
a = self.__printTopicArgNames,
L = self.__printTopicListeners)
assert self.allowedExtras == set(self.__contentMeth.keys())
import sys
self.__destination = fileObj or sys.stdout
self.__output = []
self.__content = extra or ''
unknownSel = set(self.__content) - self.allowedExtras
if unknownSel:
msg = 'These extra chars not known: %s' % ','.join(unknownSel)
raise ValueError(msg)
self.__width = width
self.__wrapper = TextWrapper(width)
self.__indent = 0
self.__indentStep = indentStep
self.__topicsBullet = bulletTopic
self.__topicItemsBullet = bulletTopicItem
self.__topicArgsBullet = bulletTopicArg
def getOutput(self):
return '\n'.join( self.__output )
def _doneTraversal(self):
if self.__destination is not None:
self.__destination.write(self.getOutput())
def _onTopic(self, topicObj):
'''This gets called for each topic. Print as per specified content.'''
# topic name
self.__wrapper.width = self.__width
indent = self.__indent
if topicObj.isAll():
topicName = self.ALL_TOPICS_NAME
else:
topicName = topicObj.getTailName()
head = '%s Topic "%s"' % (self.__topicsBullet, topicName)
self.__output.append( self.__formatDefn(indent, head) )
indent += self.__indentStep
# each extra content (assume constructor verified that chars are valid)
for item in self.__content:
function = self.__contentMeth[item]
function(indent, topicObj)
def _startChildren(self):
'''Increase the indent'''
self.__indent += self.__indentStep
def _endChildren(self):
'''Decrease the indent'''
self.__indent -= self.__indentStep
def __formatDefn(self, indent, item, defn='', sep=': '):
'''Print a definition: a block of text at a certain indent,
has item name, and an optional definition separated from import
item by sep. '''
if defn:
prefix = '%s%s%s' % (' '*indent, item, sep)
self.__wrapper.initial_indent = prefix
self.__wrapper.subsequent_indent = ' '*(indent+self.__indentStep)
return self.__wrapper.fill(defn)
else:
return '%s%s' % (' '*indent, item)
def __printTopicDescription(self, indent, topicObj):
# topic description
defn = '%s Description' % self.__topicItemsBullet
self.__output.append(
self.__formatDefn(indent, defn, topicObj.getDescription()) )
def __printTopicArgsAll(self, indent, topicObj, desc=True):
# topic kwargs
args = topicObj.getArgDescriptions()
if args:
#required, optional, complete = topicObj.getArgs()
headName = 'Names of Message arguments:'
if desc:
headName = 'Descriptions of message arguments:'
head = '%s %s' % (self.__topicItemsBullet, headName)
self.__output.append( self.__formatDefn(indent, head) )
tmpIndent = indent + self.__indentStep
required = topicObj.getArgs()[0]
for key, arg in args.iteritems():
if not desc:
arg = ''
elif key in required:
arg = '(required) %s' % arg
msg = '%s %s' % (self.__topicArgsBullet,key)
self.__output.append( self.__formatDefn(tmpIndent, msg, arg) )
def __printTopicArgNames(self, indent, topicObj):
self.__printTopicArgsAll(indent, topicObj, False)
def __printTopicListeners(self, indent, topicObj):
if topicObj.hasListeners():
listeners = topicObj.getListeners()
item = '%s Listeners:' % self.__topicItemsBullet
self.__output.append( self.__formatDefn(indent, item) )
tmpIndent = indent + self.__indentStep
for listener in listeners:
item = '%s %s (from %s)' % (self.__topicArgsBullet, listener.name(), listener.module())
self.__output.append( self.__formatDefn(tmpIndent, item) )
def printTreeDocs(pubModule, rootTopic=None, **kwargs):
'''Print out the topic tree to a file (or file-like object like a
StringIO), starting at rootTopic. If root topic should be root of
whole tree, get it from pub.getDefaultRootAllTopics import
The treeVisitor is an instance of pub.TopicTreeTraverser.
Printing the tree docs would normally involve this::
from pubsub import pub
from pubsub.utils.topictreeprinter import TopicTreePrinter
traverser = pub.TopicTreeTraverser( TopicTreePrinter(**kwargs) )
traverser.traverse( pub.getDefaultRootTopic() )
With printTreeDocs, it looks like this::
from pubsub import pub
from pubsub.utils.topictreeprinter import printTreeDocs
printTreeDocs(pub)
The kwargs are the same as for TopicTreePrinter constructor:
extra(None), width(70), indentStep(4), bulletTopic, bulletTopicItem,
bulletTopicArg, fileObj(stdout). If fileObj not given, stdout is used.'''
printer = TopicTreePrinter(**kwargs)
traverser = pubModule.TopicTreeTraverser(printer)
if rootTopic is None:
rootTopic = pubModule.getDefaultRootTopic()
traverser.traverse(rootTopic)
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