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@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@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@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@8:     def get_title (self) :
terom@8:         """
terom@8:             Return the page's title
terom@8: 
terom@8:             Defaults to the Titlecase'd file basename
terom@8:         """
terom@8: 
terom@8:         return self.basename.title()
terom@8: 
terom@8:     def get_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@8:     def get_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@8: 
terom@8:     def get_content (self) :
terom@8:         """
terom@8:             Loads the .tmpl file, and renders it
terom@8:         """
terom@8: 
terom@8:         return template.render_file(self.path)
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@8:     while segments :
terom@8:         # pop segment
terom@8:         segment = segments.pop(0)
terom@8: 
terom@8:         # add to page url
terom@8:         url_segments.append(segment)
terom@8: 
terom@8:         # translate empty -> index
terom@8:         if not segment :
terom@8:             segment = 'index'
terom@8:         
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@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: