Thuban/Model/data.py

# Copyright (C) 2003 by Intevation GmbH
# Authors:
# Bernhard Herzog <[email protected]>
#
# This program is free software under the GPL (>=v2)
# Read the file COPYING coming with the software for details.

"""Data source abstractions"""

__version__ = "$Revision$"
# $Source$
# $Id$

import os
import weakref

import shapelib
import table
import transientdb

from Thuban import _


class ShapeTable(transientdb.AutoTransientTable):

    """A Table that depends on a ShapefileStore

    Intended use is by the ShapefileStore for the table associated with
    the shapefiles.
    """

    def __init__(self, store, db, table):
        """Initialize the ShapeTable.

        Parameters:
            store -- the ShapefileStore the table is to depend on
            db -- The transient database to use
            table -- the table
        """
        transientdb.AutoTransientTable.__init__(self, db, table)
        self.store = weakref.ref(store)

    def Dependencies(self):
        """Return a tuple containing the shapestore"""
        return (self.store(),)


class ShapefileStore:

    """Combine a shapefile and the corresponding DBF file into one object"""

    def __init__(self, session, filename):
        # Make the filename absolute. The filename will be
        # interpreted relative to that anyway, but when saving a
        # session we need to compare absolute paths and it's usually
        # safer to always work with absolute paths.
        self.filename = os.path.abspath(filename)

        self.shapefile = shapelib.ShapeFile(self.filename)
        self.dbftable = table.DBFTable(filename)
        self.table = ShapeTable(self, session.TransientDB(), self.dbftable)

    def Table(self):
        """Return the table containing the attribute data"""
        return self.table

    def Shapefile(self):
        """Return the shapefile object"""
        return self.shapefile

    def FileName(self):
        """Return the filename used to open the shapefile"""
        return self.filename

    def FileType(self):
        """Return the filetype. This is always the string 'shapefile'"""
        return "shapefile"

    def Dependencies(self):
        """Return the empty tuple.

        The ShapefileStore doesn't depend on anything else.
        """
        return ()

    def OrigShapeStore(self):
        """Return None.

        The ShapefileStore was not derived from another shapestore.
        """
        return None


class DerivedShapeStore:

    """A ShapeStore derived from other shapestores or tables"""

    def __init__(self, shapestore, table):
        """Initialize the derived shapestore.

        The arguments are a shapestore for the shapedata and a table for
        the tabular data.

        Raises ValueError if the number of shapes in the shapestore
        is different from the number of rows in the table.
        """

        numShapes = shapestore.Shapefile().info()[0]
        if numShapes != table.NumRows():
            raise ValueError(_("Table not compatible with shapestore."))

        self.shapestore = shapestore
        self.table = table

    def Table(self):
        """Return the table"""
        return self.table

    def Shapefile(self):
        """Return the shapefile of the underlying shapestore"""
        return self.shapestore.Shapefile()

    def Dependencies(self):
        """Return a tuple containing the shapestore and the table"""
        return (self.shapestore, self.table)

    def OrigShapeStore(self):
        """
        Return the original shapestore the derived store was instantiated with
        """
        return self.shapestore
1	bh	723	# Copyright (C) 2003 by Intevation GmbH
2			# Authors:
3			# Bernhard Herzog <[email protected]>
4			#
5			# This program is free software under the GPL (>=v2)
6			# Read the file COPYING coming with the software for details.
7
8			"""Data source abstractions"""
9
10			__version__ = "$Revision$"
11			# $Source$
12			# $Id$
13
14			import os
15	bh	984	import weakref
16	bh	723
17			import shapelib
18			import table
19	bh	765	import transientdb
20	bh	723
21	jonathan	1261	from Thuban import _
22	bh	765
23	jonathan	1261
24	bh	984	class ShapeTable(transientdb.AutoTransientTable):
25
26			"""A Table that depends on a ShapefileStore
27
28			Intended use is by the ShapefileStore for the table associated with
29			the shapefiles.
30			"""
31
32			def __init__(self, store, db, table):
33			"""Initialize the ShapeTable.
34
35			Parameters:
36			store -- the ShapefileStore the table is to depend on
37			db -- The transient database to use
38			table -- the table
39			"""
40			transientdb.AutoTransientTable.__init__(self, db, table)
41			self.store = weakref.ref(store)
42
43			def Dependencies(self):
44			"""Return a tuple containing the shapestore"""
45			return (self.store(),)
46
47
48	bh	723	class ShapefileStore:
49
50			"""Combine a shapefile and the corresponding DBF file into one object"""
51
52			def __init__(self, session, filename):
53			# Make the filename absolute. The filename will be
54			# interpreted relative to that anyway, but when saving a
55			# session we need to compare absolute paths and it's usually
56			# safer to always work with absolute paths.
57			self.filename = os.path.abspath(filename)
58
59			self.shapefile = shapelib.ShapeFile(self.filename)
60	bh	765	self.dbftable = table.DBFTable(filename)
61	bh	984	self.table = ShapeTable(self, session.TransientDB(), self.dbftable)
62	bh	723
63			def Table(self):
64	bh	984	"""Return the table containing the attribute data"""
65	bh	723	return self.table
66
67			def Shapefile(self):
68	bh	984	"""Return the shapefile object"""
69	bh	723	return self.shapefile
70	bh	765
71	bh	984	def FileName(self):
72			"""Return the filename used to open the shapefile"""
73			return self.filename
74	bh	765
75	bh	984	def FileType(self):
76			"""Return the filetype. This is always the string 'shapefile'"""
77			return "shapefile"
78
79			def Dependencies(self):
80			"""Return the empty tuple.
81
82			The ShapefileStore doesn't depend on anything else.
83			"""
84			return ()
85
86	bh	1074	def OrigShapeStore(self):
87			"""Return None.
88	bh	984
89	bh	1074	The ShapefileStore was not derived from another shapestore.
90			"""
91			return None
92
93
94	bh	984	class DerivedShapeStore:
95
96			"""A ShapeStore derived from other shapestores or tables"""
97
98			def __init__(self, shapestore, table):
99			"""Initialize the derived shapestore.
100
101			The arguments are a shapestore for the shapedata and a table for
102			the tabular data.
103	jonathan	1261
104			Raises ValueError if the number of shapes in the shapestore
105			is different from the number of rows in the table.
106	bh	984	"""
107	jonathan	1261
108			numShapes = shapestore.Shapefile().info()[0]
109			if numShapes != table.NumRows():
110			raise ValueError(_("Table not compatible with shapestore."))
111
112	bh	984	self.shapestore = shapestore
113			self.table = table
114
115			def Table(self):
116			"""Return the table"""
117			return self.table
118
119			def Shapefile(self):
120	bh	1074	"""Return the shapefile of the underlying shapestore"""
121	bh	984	return self.shapestore.Shapefile()
122
123			def Dependencies(self):
124			"""Return a tuple containing the shapestore and the table"""
125			return (self.shapestore, self.table)
126
127	bh	1074	def OrigShapeStore(self):
128			"""
129			Return the original shapestore the derived store was instantiated with
130			"""
131			return self.shapestore
Name	Value
svn:eol-style	native
svn:keywords	Author Date Id Revision