terom@5: 
terom@7: """
terom@7:     Handling page requests
terom@7: """
terom@7: 
terom@8: # for filesystem ops
terom@8: import os, os.path
terom@7: 
terom@8: # for ResponseError
terom@8: import http
terom@8: 
terom@8: # for TemplatePage
terom@8: import template
terom@8: 
terom@8: # path to directory containing the page heirarcy
terom@8: PAGE_DIR = "pages"
terom@8: 
terom@9: # path to directory containing the list of visible pages
terom@9: PAGE_LIST_FILE = os.path.join(PAGE_DIR, "list")
terom@9: 
terom@8: class PageError (http.ResponseError) :
terom@8:     """
terom@8:         Error looking up/handling a page
terom@8:     """
terom@8: 
terom@8:     pass
terom@8: 
terom@9: class PageList (object) :
terom@9:     """
terom@9:         The list of pages
terom@9:     """
terom@9: 
terom@9:     def __init__ (self) :
terom@9:         """
terom@9:             Loads the page list from the list file
terom@9:         """
terom@9: 
terom@9:         # initialize list of pages
terom@9:         self.pages = []
terom@9: 
terom@9:         # load from file
terom@9:         self._load(PAGE_LIST_FILE)
terom@9: 
terom@9:     def _load (self, path) :
terom@9:         """
terom@9:             Processes the lines in the given file
terom@9:         """
terom@9: 
terom@9:         for line in open(path, 'rb') :
terom@9:             # ignore whitespace
terom@9:             line = line.strip()
terom@9:             
terom@9:             # ignore empty lines
terom@9:             if not line :
terom@9:                 continue
terom@9: 
terom@9:             # parse line
terom@9:             url, title = line.split(':')
terom@9: 
terom@9:             # add
terom@9:             self._add_item(url.strip(), title.strip())
terom@9:     
terom@9:     def _add_item (self, url, title) :
terom@9:         """
terom@9:             Add item to pages list
terom@9:         """
terom@9: 
terom@10:         # remove index from URL
terom@10:         if url.endswith('/index') or url == 'index' :
terom@10:             url = url[:-len('/index')]
terom@10: 
terom@9:         self.pages.append((url, title))
terom@9:     
terom@9:     def get_title (self, page) :
terom@9:         """
terom@9:             Gets the title for the given page, or None if not found
terom@9:         """
terom@9: 
terom@9:         return dict(self.pages).get(page)
terom@9: 
terom@9:     def get_siblings (self, page) :
terom@9:         """
terom@9:             Gets the (url, title) tuple list of siblings (including the given page itself) for the given page
terom@9:         """
terom@9:     
terom@9:         siblings = []
terom@9: 
terom@9:         # parent url
terom@9:         parent = os.path.split(page.url)[0]
terom@9: 
terom@9:         # how many segments in the page name
terom@9:         segment_count = len(page.url.split('/'))
terom@9:         
terom@9:         # go through all pages
terom@9:         for url, title in self.pages :
terom@9:             # it's a sibling if the parent is the same, and the number of segments it the same
terom@9:             if url.startswith(parent) and len(url.split('/')) == segment_count :
terom@9:                 siblings.append((url, title))
terom@9:         
terom@9:         # return
terom@9:         return siblings
terom@9: 
terom@9: # global singleton instance
terom@9: page_list = PageList()
terom@9: 
terom@8: class Page (object) :
terom@8:     """
terom@8:         This object represents the information about our attempt to render some specific page
terom@8:     """
terom@8: 
terom@8:     def __init__ (self, url, path, basename, url_tail) :
terom@8:         """
terom@8:             Initialize the page at the given location
terom@8: 
terom@8:             @param url the URL leading to this page
terom@8:             @param path the filesystem path to this page's file
terom@8:             @param basename the filesystem name of this page's file, without the file extension
terom@8:             @param url_trail trailing URL for this page
terom@8:         """
terom@8:         
terom@8:         # store
terom@8:         self.url = url
terom@8:         self.path = path
terom@8:         self.basename = basename
terom@8:         self.url_tail = url_tail
terom@8: 
terom@10:         # unbound
terom@10:         self.request = None
terom@10: 
terom@8:         # sub-init
terom@8:         self._init()
terom@8: 
terom@8:     def _init (self) :
terom@8:         """
terom@8:             Do initial data loading, etc
terom@8:         """
terom@8:         
terom@8:         pass
terom@8: 
terom@10:     def bind_request (self, request) :
terom@10:         """
terom@10:             Bind this page-render to the given request
terom@10:         """
terom@10: 
terom@10:         self.request = request
terom@10: 
terom@9:     @property
terom@9:     def title (self) :
terom@8:         """
terom@8:             Return the page's title
terom@8: 
terom@9:             Defaults to the retreiving the page title from page_list, or basename in Titlecase.
terom@8:         """
terom@9:         
terom@9:         # lookup in page_list
terom@9:         title = page_list.get_title(self.url)
terom@9:         
terom@9:         # fallback to titlecase
terom@9:         if not title :
terom@9:             title = self.basename.title()
terom@8: 
terom@9:         return title
terom@9:     
terom@9:     @property
terom@9:     def content (self) :
terom@8:         """
terom@8:             Return the page content as a string
terom@8:         """
terom@8: 
terom@8:         abstract
terom@8: 
terom@8: class HTMLPage (Page) :
terom@8:     """
terom@8:         A simple .html page that's just passed through directly
terom@8:     """
terom@8: 
terom@9:     @property
terom@9:     def content (self) :
terom@8:         """
terom@8:             Opens the .html file, reads and returns contents
terom@8:         """
terom@8: 
terom@8:         return open(self.path, 'rb').read()
terom@8: 
terom@8: class TemplatePage (Page) :
terom@8:     """
terom@8:         A template that's rendered using our template library
terom@8:     """
terom@9:     
terom@9:     @property
terom@9:     def content (self) :
terom@8:         """
terom@8:             Loads the .tmpl file, and renders it
terom@8:         """
terom@8: 
terom@10:         return template.render_file(self.path,
terom@10:             request     = self.request,
terom@10:         )
terom@7: 
terom@7: # list of page handlers, by type
terom@8: TYPE_HANDLERS = [
terom@8:     ('html',                    HTMLPage        ),
terom@8:     (template.TEMPLATE_EXT,     TemplatePage    ),
terom@7: ]
terom@7: 
terom@8: def _lookup_handler (url, path, filename, basename, extension, tail) :
terom@5:     """
terom@8:         We found the file that we looked for, now get its handler
terom@5:     """
terom@5: 
terom@8:     # find appropriate handler
terom@8:     for handler_ext, handler in TYPE_HANDLERS :
terom@8:         # match against file extension?
terom@8:         if handler_ext == extension :
terom@8:             # found handler, return instance
terom@8:             return handler(url, path, basename, tail)
terom@5: 
terom@8:     # no handler found
terom@8:     raise PageError("No handler found for page %r of type %r" % (url, extension))
terom@8: 
terom@8: def lookup (name) :
terom@8:     """
terom@8:         Look up and return a Page object for the given page, or raise an error
terom@8:     """
terom@8: 
terom@8:     # inital path
terom@8:     path = PAGE_DIR
terom@8:     url_segments = []
terom@8: 
terom@8:     # name segments
terom@8:     segments = name.split('/')
terom@8: 
terom@8:     # iterate through the parts of the page segments
terom@10:     while True :
terom@10:         segment = None
terom@10: 
terom@8:         # pop segment
terom@10:         if segments :
terom@10:             segment = segments.pop(0)
terom@8: 
terom@10:             url_segments.append(segment)
terom@8: 
terom@8:         # translate empty -> index
terom@8:         if not segment :
terom@8:             segment = 'index'
terom@10: 
terom@8:         # look for it in the dir
terom@8:         for filename in os.listdir(path) :
terom@8:             # build full file path
terom@8:             file_path = os.path.join(path, filename)
terom@8: 
terom@8:             # stat, recurse into subdirectory?
terom@8:             if os.path.isdir(file_path) and filename == segment :
terom@8:                 # use new dir
terom@8:                 path = file_path
terom@8: 
terom@8:                 # break for-loop to look at next segment
terom@8:                 break
terom@8:  
terom@8:             # split into basename + extension
terom@8:             basename, extension = os.path.splitext(filename)
terom@8: 
terom@8:             # ...remove that dot
terom@8:             extension = extension.lstrip('.')
terom@8:             
terom@8:             # match against requested page name?
terom@8:             if basename == segment :
terom@8:                 # found the file we wanted
terom@8:                 return _lookup_handler('/'.join(url_segments), file_path, filename, basename, extension, '/'.join(segments))
terom@8:             
terom@8:             else :
terom@8:                 # inspect next file in dir
terom@8:                 continue
terom@8: 
terom@10:         else :
terom@10:             # did not find any dir or file, break out of while loop
terom@10:             break
terom@10: 
terom@8:     # did not find the filename we were looking for in os.listdir
terom@8:     raise PageError("Page not found: %s" % name, status='404 Not Found')
terom@8: