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