#@+leo-ver=5-thin
#@+node:tbrown.20100228141752.5691: * @file leocursor.py
""" Creates a LeoCursor object that can walk around a Leo outline and decode
attributes from nodes.
Node names can be used through . (dot) notation so ``cursor.Data.Name._B`` for
example returns the body text of the Name node which is a child of the Data node
which is a child of the cursors current location.
See .../plugins/examples/leocursorexample.leo for application.
"""
import re
#@+others
#@+node:tbrown.20100206093439.5452: ** class AttribManager
[docs]class AttribManager(object):
"""Class responsible for reading / writing attributes from
vnodes for LeoCursor"""
[docs] class NotPresent(Exception):
pass
[docs] def filterBody(self, b):
"""Return the body string without any parts used to store
attributes, if this flavor of attribute manager stores attributes
in the body. If not, just return the whole body string."""
raise NotImplementedError()
[docs] def getAttrib(self, v, what):
"""Get an attribute value from a vnode"""
raise NotImplementedError()
[docs] def keys(self, v):
"""Get list of attribute keys from a vnode"""
raise NotImplementedError()
#@+node:tbrown.20100206093439.5453: ** class AM_Colon
[docs]class AM_Colon(AttribManager):
"""Attributes are in the body text as::
start-of-line letter letters-or-numbers colon space(s) attribute-value
Both::
foo:
and::
foo: all this is the value
are attributes (first one is value==''), but::
foo:value
is not (because there's no space after the colon).
"""
pattern = re.compile(r"^([A-Za-z][A-Za-z0-9_]*)(:)(\s+(\S.*))*$")
[docs] def filterBody(self, b):
return '\n'.join(
[i for i in b.split('\n')
if not self.pattern.match(i)])
[docs] def getAttrib(self, v, what):
for i in v.b.split('\n'):
m = self.pattern.match(i)
if m and m.group(1) == what:
m = m.group(3)
if m:
m = m.strip()
else:
m = '' # don't return None
return m
raise self.NotPresent()
[docs] def keys(self, v):
ans = []
for i in v.b.split('\n'):
m = self.pattern.match(i)
if m:
ans.append(m.group(1))
return ans
[docs] def has_key(self, v, what): # no access to this from LeoCursor...
for i in v.b.split('\n'):
m = self.pattern.match(i)
if m and m.group(1) == what:
return True
return False
#@+node:tbrown.20100206093439.5455: ** class AM_CapColon
[docs]class AM_CapColon(AM_Colon):
"""Like AM_Colon, but first letter must be capital."""
pattern = r"^([A-Z][A-Za-z0-9_]*:)(\s+(\S.*))*$"
#@+node:tbrown.20100206093439.5451: ** class LeoCursor
[docs]class LeoCursor(object):
"""See module docs."""
[docs] class NotPresent(Exception):
pass
#@+others
#@+node:tbrown.20100205200824.5424: *3* __init__
def __init__(self, v, other=None):
self.__v = v
if other:
self.__root = other.__root
self.__parents = other.__parents + [other]
self.__attribManagers = list(other.__attribManagers)
else:
self.__root = v
self.__attribManagers = []
self.__parents = []
#@+node:tbrown.20100205200824.9978: *3* __iter__
def __iter__(self):
for i in self.__v.children:
yield self.__at(i)
#@+node:tbrown.20100206093439.5447: *3* __call__
def __call__(self, path):
"""'Group .*/June/Event .*' - all the events that descend from June
that dsecend from a Group"""
stems = [self]
steps = path.split('/')
while steps:
step = steps.pop(0)
# print 'S',step
if not step.strip():
continue
try:
step_int = int(step)
except ValueError:
step_int = False
new_stems = []
for stem in stems:
if step_int is not False:
new_stems.append(self.__at(
(stem.__v.children or [])[step_int]))
elif step.startswith('@'):
for i in self.__attribManagers:
try:
new_stems.append(i.getAttrib(stem.__v, step[1:]))
except AttribManager.NotPresent:
pass
else:
for i in stem.__v.children or []:
#print 'V', step, i.h
if re.match(step, i.h):
new_stems.append(self.__at(i))
#print 'N',i.h
stems = new_stems
return stems
#@+node:tbrown.20100205200824.5425: *3* __getattr__
def __getattr__(self, what):
if what == '_H':
return str(self.__v.h)
elif what == '_B':
return self.__body()
elif what == '_U':
return self.__v.u
elif what == '_P':
return self.__parents
elif what == '_GNX': # or _G?
return self.__v.gnx
elif what == '_R':
return self.__at(self.__root)
elif what == '_K':
ans = []
for i in self.__attribManagers:
ans.extend(i.keys(self.__v))
return ans
for child in self.__v.children:
if child.h == what:
return self.__at(child)
for i in self.__attribManagers:
t = what[1:] if what.startswith('_') else what
try:
return i.getAttrib(self.__v, t)
except AttribManager.NotPresent:
pass
raise LeoCursor.NotPresent()
#@+node:tbrown.20100208110238.12228: *3* __getitem__
def __getitem__(self, what):
"""which can be a slice object, we let builtin list take care of it"""
if isinstance(what, int):
return self.__at(self.__v.children[what])
else:
return [self.__at(i) for i in self.__v.children[what]]
#@+node:tbrown.20100206093439.5449: *3* __body
def __body(self):
b = str(self.__v.b)
# filter out all attribs
for i in self.__attribManagers:
b = i.filterBody(b)
return b
#@+node:tbrown.20100206093439.5450: *3* __at
def __at(self, v):
return LeoCursor(v, self)
#@+node:tbrown.20100206093439.5457: *3* _setAttribManagers
def _setAttribManagers(self, mngrs):
self.__attribManagers = list(mngrs)
#@-others
#@-others
#@@language python
#@@tabwidth -4
#@-leo