I try developing a QGIS plugin for the first time and I am stuck trying to connect the python code to the dockwidget and it's contents created in QT Designer. I created a QListView inside the dockwidget and I called it "attributeList". I try connecting it with
self.dockwidget.attributeList.clear()
If I start the plugin in QGIS I get the error "'NoneType' object has no attribute 'attributeList'"
My full code is the following:
def __init__(self, iface):
"""Constructor.
:param iface: An interface instance that will be passed to this class
which provides the hook by which you can manipulate the QGIS
application at run time.
:type iface: QgsInterface
"""
# Save reference to the QGIS interface
self.iface = iface
# initialize plugin directory
self.plugin_dir = os.path.dirname(__file__)
# initialize locale
locale = QSettings().value('locale/userLocale')[0:2]
locale_path = os.path.join(
self.plugin_dir,
'i18n',
'Selektion_{}.qm'.format(locale))
if os.path.exists(locale_path):
self.translator = QTranslator()
self.translator.load(locale_path)
if qVersion() > '4.3.3':
QCoreApplication.installTranslator(self.translator)
# Declare instance attributes
self.actions = []
self.menu = self.tr(u'&Selektion')
# TODO: We are going to let the user set this up in a future iteration
self.toolbar = self.iface.addToolBar(u'Selektion')
self.toolbar.setObjectName(u'Selektion')
#print "** INITIALIZING Selektion"
self.pluginIsActive = False
self.dockwidget = None
# noinspection PyMethodMayBeStatic
def tr(self, message):
"""Get the translation for a string using Qt translation API.
We implement this ourselves since we do not inherit QObject.
:param message: String for translation.
:type message: str, QString
:returns: Translated version of message.
:rtype: QString
"""
# noinspection PyTypeChecker,PyArgumentList,PyCallByClass
return QCoreApplication.translate('Selektion', message)
def add_action(
self,
icon_path,
text,
callback,
enabled_flag=True,
add_to_menu=True,
add_to_toolbar=True,
status_tip=None,
whats_this=None,
parent=None):
"""Add a toolbar icon to the toolbar.
:param icon_path: Path to the icon for this action. Can be a resource
path (e.g. ':/plugins/foo/bar.png') or a normal file system path.
:type icon_path: str
:param text: Text that should be shown in menu items for this action.
:type text: str
:param callback: Function to be called when the action is triggered.
:type callback: function
:param enabled_flag: A flag indicating if the action should be enabled
by default. Defaults to True.
:type enabled_flag: bool
:param add_to_menu: Flag indicating whether the action should also
be added to the menu. Defaults to True.
:type add_to_menu: bool
:param add_to_toolbar: Flag indicating whether the action should also
be added to the toolbar. Defaults to True.
:type add_to_toolbar: bool
:param status_tip: Optional text to show in a popup when mouse pointer
hovers over the action.
:type status_tip: str
:param parent: Parent widget for the new action. Defaults None.
:type parent: QWidget
:param whats_this: Optional text to show in the status bar when the
mouse pointer hovers over the action.
:returns: The action that was created. Note that the action is also
added to self.actions list.
:rtype: QAction
"""
icon = QIcon(icon_path)
action = QAction(icon, text, parent)
action.triggered.connect(callback)
action.setEnabled(enabled_flag)
if status_tip is not None:
action.setStatusTip(status_tip)
if whats_this is not None:
action.setWhatsThis(whats_this)
if add_to_toolbar:
self.toolbar.addAction(action)
if add_to_menu:
self.iface.addPluginToMenu(
self.menu,
action)
self.actions.append(action)
return action
def initGui(self):
"""Create the menu entries and toolbar icons inside the QGIS GUI."""
icon_path = ':/plugins/selektion/icon.png'
self.add_action(
icon_path,
text=self.tr(u'selektion'),
callback=self.run,
parent=self.iface.mainWindow())
self.attributes()
def attributes(self):
self.dockwidget.attributeList.clear()
#--------------------------------------------------------------------------
def onClosePlugin(self):
"""Cleanup necessary items here when plugin dockwidget is closed"""
#print "** CLOSING Selektion"
# disconnects
self.dockwidget.closingPlugin.disconnect(self.onClosePlugin)
# remove this statement if dockwidget is to remain
# for reuse if plugin is reopened
# Commented next statement since it causes QGIS crashe
# when closing the docked window:
# self.dockwidget = None
self.pluginIsActive = False
def unload(self):
"""Removes the plugin menu item and icon from QGIS GUI."""
#print "** UNLOAD Selektion"
for action in self.actions:
self.iface.removePluginMenu(
self.tr(u'&Selektion'),
action)
self.iface.removeToolBarIcon(action)
# remove the toolbar
del self.toolbar
#--------------------------------------------------------------------------
def run(self):
"""Run method that loads and starts the plugin"""
if not self.pluginIsActive:
self.pluginIsActive = True
#print "** STARTING Selektion"
# dockwidget may not exist if:
# first run of plugin
# removed on close (see self.onClosePlugin method)
if self.dockwidget == None():
# Create the dockwidget (after translation) and keep reference
self.dockwidget = SelektionDockWidget()
# connect to provide cleanup on closing of dockwidget
self.dockwidget.closingPlugin.connect(self.onClosePlugin)
# show the dockwidget
# TODO: fix to allow choice of dock location
self.iface.addDockWidget(Qt.RightDockWidgetArea, self.dockwidget)
self.dockwidget.show()
You can find the line I mentioned right after the def initGui
