PyQGIS AttributeError – ‘NoneType’ Object Has No Attribute ‘pushButton’

attributeerrorpyqgispyqtqgis-plugins

I am using PyQt5 working in QGIS to create a simple plugin. I started by creating a pushButton with QtCreator and create an event using this code:

from PyQt5.QtCore import QSettings, QTranslator, qVersion, QCoreApplication, Qt
from PyQt5.QtGui import QIcon
from PyQt5.QtWidgets import QAction,QFileDialog
from PyQt5 import QtWidgets
from qgis.core import QgsProject
from .resources import *

from .GISIFE_dockwidget import GIS_IFEDockWidget
import os.path


class GIS_IFE:
    """QGIS Plugin Implementation."""

    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',
            'GIS_IFE_{}.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'&CAD_PyGIS')
        # TODO: We are going to let the user set this up in a future iteration
        self.toolbar = self.iface.addToolBar(u'GIS_IFE')
        self.toolbar.setObjectName(u'GIS_IFE')

        #print "** INITIALIZING GIS_IFE"

        self.pluginIsActive = False
        self.dockwidget = None

        # Test

        self.dockwidget.pushButton.clicked.connect(self.Find())


    # 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('GIS_IFE', 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/GISIFE/icon.png'
        self.add_action(
            icon_path,
            text=self.tr(u'CAD_PyGIS'),
            callback=self.run,
            parent=self.iface.mainWindow())

    #--------------------------------------------------------------------------

    def onClosePlugin(self):
        """Cleanup necessary items here when plugin dockwidget is closed"""

        #print "** CLOSING GIS_IFE"

        # 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 GIS_IFE"

        for action in self.actions:
            self.iface.removePluginMenu(
                self.tr(u'&CAD_PyGIS'),
                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 GIS_IFE"

            # 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 = GIS_IFEDockWidget()

            # 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()


    def Find(self):
        """Localisation des R/T/PLLE"""
        red=comboBox.get()
        self.dockwidget.lineEdit.setText(red)

I got this Error :

AttributeError: 'NoneType' object has no attribute 'pushButton'

Best Answer

You set self.dockwidget=None, And then you connect a method to "the click event of the push button item of None object". So that you get that error.

 self.dockwidget = None
 # Now, self.dockwidget is None and None object has no any pushButton item.
 self.dockwidget.pushButton.clicked.connect(self.Find()) # <- CUT THIS LINE

You should add self.dockwidget.pushButton.clicked.connect(self.Find()) line, after creating a QDockWidget object which has QPushButton object. (GIS_IFEDockWidget() in your case ).

So add that line after self.dockwidget = GIS_IFEDockWidget() line within run method:

def run(self):
    """Run method that loads and starts the plugin"""

    if not self.pluginIsActive:
        self.pluginIsActive = True

        #print "** STARTING GIS_IFE"
        if self.dockwidget == None:
            # Create the dockwidget (after translation) and keep reference
            self.dockwidget = GIS_IFEDockWidget()

        self.dockwidget.pushButton.clicked.connect(self.Find()) # <- ADD RIGHT HERE

        # connect to provide cleanup on closing of dockwidget
        self.dockwidget.closingPlugin.connect(self.onClosePlugin)
        .
        .
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