1

     2

import os, os.path

     3

     4

from qmsk.web import http, template, handler

     5

     6

import page, page_tree

     7

     8

class PageMapper (handler.RequestHandler) :

     9

    """

    10

        Translates requests to handlers based on a filesystem directory containing various kinds of files

    11

    """

    12

    13

    # list of page handlers, by type

    14

    PAGE_TYPES = [

    15

        ('html',                    page.HTMLPage           ),

    16

        (template.TEMPLATE_EXT,     page.TemplatePage       ),

    17

    ]

    18

    19

    def __init__ (self, path, templates) :

    20

        """

    21

            Create, path is where the pages are stored. The list of pages is loaded from $path/list

    22

        """

    23

    24

        # store

    25

        self.path = path 

    26

        self.templates = templates

    27

    28

        # load the page tree

    29

        self.tree = page_tree.PageTree(path + '/list')

    30

    31

    def _lookup_page_type (self, url, path, filename, basename, extension, tail) :

    32

        """

    33

            We found the file that we looked for, now get the correct type

    34

        """

    35

    36

        # find appropriate handler

    37

        for handler_ext, type in self.PAGE_TYPES :

    38

            # match against file extension?

    39

            if handler_ext == extension :

    40

                # found handler, return instance

    41

                return type(self, url, path, basename, tail)

    42

    43

        # no handler found

    44

        raise PageError("No handler found for page %r of type %r" % (url, extension))

    45

    46

    def _lookup_page (self, name) :

    47

        """

    48

            Look up and return a Page object for the given page, or raise an error

    49

        """

    50

    51

        # inital path

    52

        path = self.path

    53

        url_segments = []

    54

    55

        # name segments

    56

        segments = name.split('/')

    57

    58

        # iterate through the parts of the page segments

    59

        while True :

    60

            segment = None

    61

    62

            # pop segment

    63

            if segments :

    64

                segment = segments.pop(0)

    65

    66

                url_segments.append(segment)

    67

    68

            # translate empty -> index

    69

            if not segment :

    70

                segment = 'index'

    71

    72

            # look for it in the dir

    73

            for filename in os.listdir(path) :

    74

                # build full file path

    75

                file_path = os.path.join(path, filename)

    76

    77

                # stat, recurse into subdirectory?

    78

                if os.path.isdir(file_path) and filename == segment :

    79

                    # use new dir

    80

                    path = file_path

    81

    82

                    # break for-loop to look at next segment

    83

                    break

    84

    85

                # split into basename + extension

    86

                basename, extension = os.path.splitext(filename)

    87

    88

                # ...remove that dot

    89

                extension = extension.lstrip('.')

    90

    91

                # match against requested page name?

    92

                if basename == segment :

    93

                    # found the file we wanted

    94

                    return self._lookup_page_type('/'.join(url_segments), file_path, filename, basename, extension, '/'.join(segments))

    95

    96

                else :

    97

                    # inspect next file in dir

    98

                    continue

    99

   100

            else :

   101

                # did not find any dir or file, break out of while loop

   102

                break

   103

   104

        # did not find the filename we were looking for in os.listdir

   106

   107

    def handle_request (self, request) :

   108

        """

   109

            Looks up the appropriate Page, and then renders it

   110

        """

   111

   112

        # determine the page name

   113

        page_name = request.get_page_name()

   114

   115

        # get the page handler

   116

        page = self._lookup_page(page_name)

   117

   118

        # pass on

   119

        return page.handle_request(request)

   120