[Qgis-developer] qgis+python bindings: failed to load vector layer

[Luca Mandolesi]

Hi,
and thanks a lot for reply. I'm sorry for my many questions but I'm
little "disperate"!
My first problem is how to set under UNIX the LD_LIBRARY_PATH (exist
it, under Mac OS X?!!!).
The code is the same of your 2nd tutorial: 2_basic_main_window, and
I've modified the python path and the qgis_prefix variable.

# Original sources Copyright (c) 2006 by Tim Sutton
#
# ported to Python by Martin Dobias
#
# licensed under the terms of GNU GPL 2
import sys
sys.path.append('/Users/heywoodstock/apps/Contents/MacOS/share/qgis/python/')
from PyQt4 import QtCore, QtGui
from mainwindow_ui import Ui_MainWindow
from qgis.core import *
from qgis.gui import *
import sys

qgis_prefix = "/Users/heywoodstock/apps/Contents/MacOS/"

class MainWindow(QtGui.QMainWindow, Ui_MainWindow):

  def __init__(self):
    QtGui.QMainWindow.__init__(self)

    # required by Qt4 to initialize the UI
    self.setupUi(self)

    # create map canvas
    self.canvas = QgsMapCanvas()
    self.canvas.setCanvasColor(QtGui.QColor(255,255,255))
    self.canvas.enableAntiAliasing(True)
    self.canvas.useQImageToRender(False)
    self.canvas.show()

    # lay our widgets out in the main window
    self.layout = QtGui.QVBoxLayout(self.frameMap)
    self.layout.addWidget(self.canvas)

    # create the actions behaviours
    self.connect(self.mpActionAddLayer, QtCore.SIGNAL("triggered()"),
self.addLayer)
    self.connect(self.mpActionZoomIn, QtCore.SIGNAL("triggered()"), self.zoomIn)
    self.connect(self.mpActionZoomOut, QtCore.SIGNAL("triggered()"),
self.zoomOut)
    self.connect(self.mpActionPan, QtCore.SIGNAL("triggered()"), self.pan)

    # create a little toolbar
    self.toolbar = self.addToolBar("File");
    self.toolbar.addAction(self.mpActionAddLayer);
    self.toolbar.addAction(self.mpActionZoomIn);
    self.toolbar.addAction(self.mpActionZoomOut);
    self.toolbar.addAction(self.mpActionPan);

    # create the map tools
    self.toolPan = QgsMapToolPan(self.canvas)
    self.toolPan.setAction(self.mpActionPan)
    self.toolZoomIn = QgsMapToolZoom(self.canvas, False) # false = in
    self.toolZoomIn.setAction(self.mpActionZoomIn)
    self.toolZoomOut = QgsMapToolZoom(self.canvas, True) # true = out
    self.toolZoomOut.setAction(self.mpActionZoomOut)


  def zoomIn(self):
    self.canvas.setMapTool(self.toolZoomIn)

  def zoomOut(self):
    self.canvas.setMapTool(self.toolZoomOut)

  def pan(self):
    self.canvas.setMapTool(self.toolPan)

  def addLayer(self):
    """add a (hardcoded) layer and zoom to its extent"""

    layerPath = "../data/test.shp"
    layerName = "test"
    layerProvider = "ogr"

    # create layer
    layer = QgsVectorLayer(layerPath, layerName, layerProvider)

    if not layer.isValid():
      return

    # add layer to the registry
    QgsMapLayerRegistry.instance().addMapLayer(layer);

    # set extent to the extent of our layer
    self.canvas.setExtent(layer.extent())

    # set the map canvas layer set
    cl = QgsMapCanvasLayer(layer)
    layers = [cl]
    self.canvas.setLayerSet(layers)

def main(argv):
  # create Qt application
  app = QtGui.QApplication(argv)

  # initialize qgis libraries
  QgsApplication.setPrefixPath(qgis_prefix, True)
  QgsApplication.initQgis()

  # create main window
  wnd = MainWindow()
  wnd.show()

  # run!
  retval = app.exec_()

  # exit
  QgsApplication.exitQgis()
  sys.exit(retval)


if __name__ == "__main__":
  main(sys.argv)

Also, during the installation I've recived these warning about ld
lybrary and GDAL:

[ 81%] Building CXX object
src/plugins/grid_maker/CMakeFiles/gridmakerplugin.dir/qrc_gridmaker_plugin.o
Linking CXX shared module libgridmakerplugin.so
/usr/bin/ld: warning multiple definitions of symbol _DBFCreate
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFCreate in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFCreate
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteStringAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteStringAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteStringAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteNULLAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteNULLAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteNULLAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteLogicalAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteLogicalAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteLogicalAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteIntegerAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteIntegerAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteIntegerAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFClose
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFClose in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFClose
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteDoubleAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteDoubleAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteDoubleAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteAttributeDirectly
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFWriteAttributeDirectly in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteAttributeDirectly
/usr/bin/ld: warning multiple definitions of symbol _DBFUpdateHeader
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFUpdateHeader in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFUpdateHeader
/usr/bin/ld: warning multiple definitions of symbol _DBFReadTuple
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFReadTuple
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFReadTuple
/usr/bin/ld: warning multiple definitions of symbol _DBFReadStringAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFReadStringAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFReadStringAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFReadLogicalAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFReadLogicalAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFReadLogicalAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFReadIntegerAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFReadIntegerAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFReadIntegerAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFReadDoubleAttribute
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFReadDoubleAttribute in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFReadDoubleAttribute
/usr/bin/ld: warning multiple definitions of symbol _DBFOpen
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFOpen in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFOpen
/usr/bin/ld: warning multiple definitions of symbol _DBFMarkRecordDeleted
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFMarkRecordDeleted in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFMarkRecordDeleted
/usr/bin/ld: warning multiple definitions of symbol _DBFCloneEmpty
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFCloneEmpty
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFCloneEmpty
/usr/bin/ld: warning multiple definitions of symbol _DBFAddNativeFieldType
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFAddNativeFieldType in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFAddNativeFieldType
/usr/bin/ld: warning multiple definitions of symbol _DBFAddField
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFAddField in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFAddField
/usr/bin/ld: warning multiple definitions of symbol _DBFIsRecordDeleted
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFIsRecordDeleted in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFIsRecordDeleted
/usr/bin/ld: warning multiple definitions of symbol _DBFIsAttributeNULL
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFIsAttributeNULL in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFIsAttributeNULL
/usr/bin/ld: warning multiple definitions of symbol _DBFGetRecordCount
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFGetRecordCount in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFGetRecordCount
/usr/bin/ld: warning multiple definitions of symbol _DBFGetNativeFieldType
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFGetNativeFieldType in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFGetNativeFieldType
/usr/bin/ld: warning multiple definitions of symbol _DBFGetFieldInfo
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFGetFieldInfo in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFGetFieldInfo
/usr/bin/ld: warning multiple definitions of symbol _DBFGetFieldIndex
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFGetFieldIndex in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFGetFieldIndex
/usr/bin/ld: warning multiple definitions of symbol _DBFGetFieldCount
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of
_DBFGetFieldCount in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFGetFieldCount
/usr/bin/ld: warning multiple definitions of symbol _DBFWriteTuple
CMakeFiles/gridmakerplugin.dir/dbfopen.o definition of _DBFWriteTuple
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _DBFWriteTuple
/usr/bin/ld: warning multiple definitions of symbol _SHPTypeName
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPTypeName in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPTypeName
/usr/bin/ld: warning multiple definitions of symbol _SHPRewindObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPRewindObject in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPRewindObject
/usr/bin/ld: warning multiple definitions of symbol _SHPCreateSimpleObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPCreateSimpleObject in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPCreateSimpleObject
/usr/bin/ld: warning multiple definitions of symbol _SHPOpen
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPOpen in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPOpen
/usr/bin/ld: warning multiple definitions of symbol _SHPClose
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPClose in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPClose
/usr/bin/ld: warning multiple definitions of symbol _SHPCreateObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPCreateObject in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPCreateObject
/usr/bin/ld: warning multiple definitions of symbol _SHPDestroyObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPDestroyObject in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPDestroyObject
/usr/bin/ld: warning multiple definitions of symbol _SHPGetInfo
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPGetInfo in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPGetInfo
/usr/bin/ld: warning multiple definitions of symbol _SHPReadObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPReadObject
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPReadObject
/usr/bin/ld: warning multiple definitions of symbol _SHPCreate
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPCreate in
section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPCreate
/usr/bin/ld: warning multiple definitions of symbol _SHPWriteHeader
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPWriteHeader
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPWriteHeader
/usr/bin/ld: warning multiple definitions of symbol _SHPWriteObject
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of _SHPWriteObject
in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPWriteObject
/usr/bin/ld: warning multiple definitions of symbol _SHPComputeExtents
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPComputeExtents in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPComputeExtents
/usr/bin/ld: warning multiple definitions of symbol _SHPPartTypeName
CMakeFiles/gridmakerplugin.dir/shpopen.o definition of
_SHPPartTypeName in section (__TEXT,__text)
/Library/Frameworks/GDAL.framework/unix/lib/libgdal.dylib(single
module) definition of _SHPPartTypeName


I guess that it's here my problem!

Thank you very very much and compliments for your good job with qgis
and python bindings!!! I'm enthusiastic for this!!!


bye bye