gis: added spatial database creation utility and fixed a bug in gdal geomtype module.

git-svn-id: http://code.djangoproject.com/svn/django/branches/gis@5761 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/gis/gdal/geomtype.py

@@ -1,4 +1,5 @@
 from types import StringType
+from django.contrib.gis.gdal.error import OGRException
 
 #### OGRGeomType ####
 class OGRGeomType(object):

django/contrib/gis/utils/__init__.py

@@ -1,2 +1,3 @@
 from LayerMapping import LayerMapping
 from inspect_data import sample
+from spatial_db import create_spatial_db

django/contrib/gis/utils/spatial_db.py

@@ -0,0 +1,190 @@
+from django.conf import settings
+from django.core.management import syncdb
+from django.db import connection, backend
+from django.test.utils import _set_autocommit, TEST_DATABASE_PREFIX
+from commands import getstatusoutput
+import os, re, sys
+
+def create_lang(db_name, verbosity=1):
+    "This sets up the pl/pgsql language on the given database."
+
+    # Getting the command-line options for the shell command
+    options = get_cmd_options(db_name)
+
+    # Constructing the 'createlang' command.
+    createlang_cmd = 'createlang %splpgsql' % options
+    if verbosity >= 1: print createlang_cmd
+
+    # Must have database super-user privileges to execute createlang -- it must
+    #  also be in your path.
+    status, output = getstatusoutput(createlang_cmd)
+
+    # Checking the status of the command, 0 => execution successful
+    if status != 0:
+        raise Exception, "Error executing 'plpgsql' command: %s\n" % output
+        
+
+def _create_with_cursor(db_name, verbosity=1, autoclobber=False):
+    "Creates database with psycopg2 cursor."
+
+    # Constructing the necessary SQL to create the database (the DATABASE_USER
+    #  must possess the privileges to create a database)
+    create_sql = 'CREATE DATABASE %s OWNER %s' % (backend.quote_name(db_name),
+                                                  settings.DATABASE_USER)
+    cursor = connection.cursor()
+    _set_autocommit(connection)
+
+    try:
+        # Trying to create the database first.
+        cursor.execute(create_sql)
+    except Exception, e:
+        # Drop and recreate, if necessary.
+        if not autoclobber:
+            confirm = raw_input("\nIt appears the database, %s, already exists. Type 'yes' to delete it, or 'no' to cancel: " % db_name)
+        if autoclobber or confirm == 'yes':
+            if verbosity >= 1: print 'Destroying old spatial database...'
+            drop_db(db_name)
+            if verbosity >= 1: print 'Creating new spatial database...'
+            cursor.execute(create_sql)
+        else:
+            raise Exception, 'Spatial Database Creation canceled.'
+    
+created_regex = re.compile(r'^createdb: database creation failed: ERROR:  database ".+" already exists')
+def _create_with_shell(db_name, verbosity=1, autoclobber=False):
+    """If no spatial database already exists, then using a cursor will not work.  Thus, a
+    `createdb` command will be issued through the shell to bootstrap the database."""
+
+    # Getting the command-line options for the shell command
+    options = get_cmd_options(False)
+    create_cmd = 'createdb -O %s %s%s' % (settings.DATABASE_USER, options, db_name)
+    if verbosity >= 1: print create_cmd
+
+    # Attempting to create the database.
+    status, output = getstatusoutput(create_cmd)
+    if status != 0:
+        if created_regex.match(output):
+            if not autoclobber:
+                confirm = raw_input("\nIt appears the database, %s, already exists. Type 'yes' to delete it, or 'no' to cancel: " % db_name)
+            if autoclobber or confirm == 'yes':
+                if verbosity >= 1: print 'Destroying old spatial database...'
+                drop_cmd = 'dropdb %s%s' % (options, db_name)
+                status, output = getstatusoutput(drop_cmd)
+                if status != 0: 
+                    raise Exception, 'Could not drop database %s: %s' % (db_name, output)
+                if verbosity >= 1: print 'Creating new spatial database...'
+                status, output = getstatusoutput(create_cmd)
+                if status != 0:
+                    raise Exception, 'Could not create database after dropping: %s' % output
+            else:
+                raise Exception, 'Spatial Database Creation canceled.'
+        else:
+            raise Exception, 'Unknown error occurred in creating database: %s' % output
+
+def create_spatial_db(test=False, verbosity=1, autoclobber=False):
+    "This Python routine creates a spatial database based on settings.py."
+
+    # Making sure we're using PostgreSQL and psycopg2
+    if settings.DATABASE_ENGINE != 'postgresql_psycopg2':
+        raise Exception, 'Spatial database creation only supported postgresql_psycopg2 platform.'
+
+    # This routine depends on getstatusoutput(), which does not work on Windows.
+    # TODO: Consider executing shell commands with popen for Windows compatibility
+    if os.name == 'nt':
+        raise Exception, 'Automatic spatial database creation only supported on *NIX platforms.'
+
+    # Getting the spatial database name
+    if test: 
+        db_name = get_spatial_db(test=True)
+        _create_with_cursor(db_name, verbosity=verbosity, autoclobber=autoclobber)
+    else: 
+        db_name = get_spatial_db()
+        _create_with_shell(db_name, verbosity=verbosity, autoclobber=autoclobber)
+
+    # Creating the db language.
+    create_lang(db_name, verbosity=verbosity)
+
+    # Now adding in the PostGIS routines.
+    load_postgis_sql(db_name, verbosity=verbosity)
+
+    if verbosity >= 1: print 'Creation of spatial database %s successful.' % db_name
+
+    # Closing the connection
+    connection.close()
+    settings.DATABASE_NAME = db_name
+
+    # Syncing the database
+    syncdb(verbosity, interactive=False)
+
+    # Get a cursor (even though we don't need one yet). This has
+    # the side effect of initializing the test database.
+    cursor = connection.cursor()
+    
+def drop_db(db_name=False, test=False):
+    "Using the cursor, drops the given database.  All exceptions will be propagated up."
+    if not db_name: db_name = get_spatial_db(test=test)
+    cursor = connection.cursor()
+    cursor.execute("DROP DATABASE %s" % backend.quote_name(db_name))
+
+def get_cmd_options(db_name):
+    "Obtains the command-line PostgreSQL connection options for shell commands."
+    # The db_name parameter is optional
+    if db_name:
+        options = '-d %s -U %s ' % (db_name, settings.DATABASE_USER)
+    else:
+        options = '-U %s ' % settings.DATABASE_USER
+    if settings.DATABASE_HOST:
+        options += '-h %s ' % settings.DATABASE_HOST
+    if settings.DATABASE_PORT:
+        options += '-p %s ' % settings.DATABASE_PORT
+    return options
+
+def get_spatial_db(test=False):
+    """This routine returns the name of the spatial database.
+    Set the 'test' keyword for the test spatial database name."""
+    if test:
+        if settings.TEST_DATABASE_NAME:
+            test_db_name = settings.TEST_DATABASE_NAME
+        else:
+            test_db_name = TEST_DATABASE_PREFIX + settings.DATABASE_NAME
+        return test_db_name
+    else:
+        if not settings.DATABASE_NAME:
+            raise Exception, 'must configure DATABASE_NAME in settings.py'
+        return settings.DATABASE_NAME
+
+def load_postgis_sql(db_name, verbosity=1):
+    "This routine loads up the PostGIS SQL files lwpostgis.sql and spatial_ref_sys.sql."
+
+    # Getting the path to the PostGIS SQL
+    try:
+        # POSTGIS_SQL_PATH may be placed in settings to tell GeoDjango where the 
+        #   PostGIS SQL files are located
+        sql_path = settings.POSTGIS_SQL_PATH
+    except AttributeError:
+        sql_path = '/usr/local/share'
+
+    # The PostGIS SQL post-creation files.
+    lwpostgis_file = os.path.join(sql_path, 'lwpostgis.sql')
+    srefsys_file   = os.path.join(sql_path, 'spatial_ref_sys.sql')
+    if not os.path.isfile(lwpostgis_file):
+        raise Exception, 'Could not find PostGIS function definitions in %s' % lwpostgis_file
+    if not os.path.isfile(srefsys_file):
+        raise Exception, 'Could not find PostGIS spatial reference system definitions in %s' % srefsys_file
+
+    # Getting the psql command-line options.
+    options = get_cmd_options(db_name)
+    
+    # Now trying to load up the PostGIS functions
+    cmd = 'psql %s-f %s' % (options, lwpostgis_file)
+    if verbosity >= 1: print cmd
+    status, output = getstatusoutput(cmd)
+    if status != 0:
+        raise Exception, 'Error in loading PostGIS lwgeometry routines.'
+
+    # Now trying to load up the Spatial Reference System table
+    cmd = 'psql %s-f %s' % (options, srefsys_file)
+    if verbosity >= 1: print cmd
+    status, output = getstatusoutput(cmd)
+    if status !=0:
+        raise Exception, 'Error in loading PostGIS spatial_ref_sys table.'
+