#!/usr/bin/env python
"""Create menus and crumbs from a site hierarchy.
You define the site hierarchy as lists/tuples. Each location in the hierarchy
is a (url, description) tuple. Each list has the base URL/text in the 0
position, and all the children coming after it. Any child can be a list,
representing further depth to the hierarchy. See the end of the file for an
example hierarchy.
Use Hierarchy(contents, currentURL), where contents is this hierarchy, and
currentURL is the position you are currently in.
The menubar and crumbs methods give you the HTML output.
There are methods you can override to customize the HTML output.
"""
##################################################
# DEPENDENCIES
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
##################################################
# CLASSES
class Hierarchy:
def __init__(self, hierarchy, currentURL, prefix='', menuCSSClass=None,
crumbCSSClass=None):
"""
hierarchy is described above, currentURL should be somewhere in
the hierarchy. prefix will be added before all of the URLs (to
help mitigate the problems with absolute URLs), and if given,
cssClass will be used for both links *and* nonlinks.
"""
self._contents = hierarchy
self._currentURL = currentURL
if menuCSSClass:
self._menuCSSClass = ' class="%s"' % menuCSSClass
else:
self._menuCSSClass = ''
if crumbCSSClass:
self._crumbCSSClass = ' class="%s"' % crumbCSSClass
else:
self._crumbCSSClass = ''
self._prefix = prefix
# Main output methods
def menuList(self, menuCSSClass=None):
"""An indented menu list"""
if menuCSSClass:
self._menuCSSClass = ' class="%s"' % menuCSSClass
stream = StringIO()
for item in self._contents[1:]:
self._menubarRecurse(item, 0, stream)
return stream.getvalue()
def crumbs(self, crumbCSSClass=None):
"""The home>where>you>are crumbs"""
if crumbCSSClass:
self._crumbCSSClass = ' class="%s"' % crumbCSSClass
path = []
pos = self._contents
while True:
# This is not the fastest algorithm, I'm afraid.
# But it probably won't be for a huge hierarchy anyway.
foundAny = False
path.append(pos[0])
for item in pos[1:]:
if self._inContents(item):
if isinstance(item, tuple):
path.append(item)
break
else:
pos = item
foundAny = True
break
if not foundAny:
break
if len(path) == 1:
return self.emptyCrumb()
return self.crumbSeperator().join(
map(lambda x, self=self: self.crumbLink(x[0], x[1]), path)) + \
self.crumbTerminator()
# Methods to control the Aesthetics
# - override these methods for your own look
def menuLink(self, url, text, indent):
if url == self._currentURL or self._prefix + url == self._currentURL:
return '%s%s
\n' % (' ' * 2 * indent,
self._menuCSSClass, text)
else:
return '%s%s
\n' % \
(' '*2*indent, self._prefix, url, # noqa: E226,E501 missing whitespace around operator
self._menuCSSClass, text)
def crumbLink(self, url, text):
if url == self._currentURL or self._prefix + url == self._currentURL:
return '%s' % (self._crumbCSSClass, text)
else:
return '%s' % \
(self._prefix, url, self._crumbCSSClass, text)
def crumbSeperator(self):
return ' > '
def crumbTerminator(self):
return ''
def emptyCrumb(self):
"""When you are at the homepage"""
return ''
# internal methods
def _menubarRecurse(self, contents, indent, stream):
if isinstance(contents, tuple):
url, text = contents
rest = []
else:
url, text = contents[0]
rest = contents[1:]
stream.write(self.menuLink(url, text, indent))
if self._inContents(contents):
for item in rest:
self._menubarRecurse(item, indent + 1, stream)
def _inContents(self, contents):
if isinstance(contents, tuple):
return self._currentURL == contents[0]
for item in contents:
if self._inContents(item):
return True
return False
##################################################
# from the command line
if __name__ == '__main__':
hierarchy = [
('/', 'home'),
('/about', 'About Us'),
[('/services', 'Services'),
[('/services/products', 'Products'),
('/services/products/widget', 'The Widget'),
('/services/products/wedge', 'The Wedge'),
('/services/products/thimble', 'The Thimble'),
],
('/services/prices', 'Prices'),
],
('/contact', 'Contact Us'),
]
for url in ['/', '/services', '/services/products/widget', '/contact']:
print('
', '='*50) # noqa: E226 missing whitespace around operator
print('
%s:
\n' % url)
n = Hierarchy(hierarchy, url, menuCSSClass='menu',
crumbCSSClass='crumb', prefix='/here')
print(n.menuList())
print('
', '-'*50) # noqa: E226 missing whitespace around operator print(n.crumbs())