def _enableProcessing():
     loadPlugin("processing")
     startPlugin("processing")
     QtCore.QSettings().setValue('/PythonPlugins/processing', True)
     updateAvailablePlugins()
     updatePluginManager()
     assert "processing" in active_plugins

 def setUp(self):
     self.qgis_app, self.canvas, self.iface = set_up_interface()
     utils.plugin_paths = [os.path.expanduser('~/.qgis2/python/plugins')]
     utils.updateAvailablePlugins()
     utils.loadPlugin('pointsamplingtool')
     utils.iface = self.iface
     utils.startPlugin('pointsamplingtool')

  def run(self):
    plugin = currentPlugin()
    #update the plugin list first! The plugin could be removed from the list if was temporarily broken.
    updateAvailablePlugins()
    #try to load from scratch the plugin saved in QSettings if not loaded
    if plugin not in plugins:
      try:
        loadPlugin(plugin)
        startPlugin(plugin)
      except:
        pass
    updateAvailablePlugins()
    #give one chance for correct (not a loop)
    if plugin not in plugins:
      self.configure()
      plugin = currentPlugin()
    if plugin in plugins:
      state = self.iface.mainWindow().saveState()

      # Unload submodules
      for key in [key for key in sys.modules.keys()]:
        if '{}.'.format(plugin) in key:
          if hasattr(sys.modules[key], 'qCleanupResources'):
            sys.modules[key].qCleanupResources()
          del sys.modules[key]

      reloadPlugin(plugin)
      self.iface.mainWindow().restoreState(state)
      self.iface.messageBar().pushMessage("<b>{}</b> reloaded.".format(plugin), QGis.Info)

    def installFromZipFile(self, filePath):
        if not os.path.isfile(filePath):
            return

        settings = QgsSettings()
        settings.setValue(settingsGroup + '/lastZipDirectory',
                          QFileInfo(filePath).absoluteDir().absolutePath())

        error = False
        infoString = None

        with zipfile.ZipFile(filePath, 'r') as zf:
            pluginName = os.path.split(zf.namelist()[0])[0]

        pluginFileName = os.path.splitext(os.path.basename(filePath))[0]

        pluginsDirectory = qgis.utils.home_plugin_path
        if not QDir(pluginsDirectory).exists():
            QDir().mkpath(pluginsDirectory)

        # If the target directory already exists as a link,
        # remove the link without resolving
        QFile(os.path.join(pluginsDirectory, pluginFileName)).remove()

        try:
            # Test extraction. If fails, then exception will be raised
            # and no removing occurs
            unzip(str(filePath), str(pluginsDirectory))
            # Removing old plugin files if exist
            removeDir(QDir.cleanPath(os.path.join(pluginsDirectory, pluginFileName)))
            # Extract new files
            unzip(str(filePath), str(pluginsDirectory))
        except:
            error = True
            infoString = (self.tr("Plugin installation failed"),
                          self.tr("Failed to unzip the plugin package\n{}.\nProbably it is broken".format(filePath)))

        if infoString is None:
            updateAvailablePlugins()
            loadPlugin(pluginName)
            plugins.getAllInstalled(testLoad=True)
            plugins.rebuild()

            if settings.contains('/PythonPlugins/' + pluginName):
                if settings.value('/PythonPlugins/' + pluginName, False, bool):
                    startPlugin(pluginName)
                    reloadPlugin(pluginName)
                else:
                    unloadPlugin(pluginName)
                    loadPlugin(pluginName)
            else:
                if startPlugin(pluginName):
                    settings.setValue('/PythonPlugins/' + pluginName, True)
            infoString = (self.tr("Plugin installed successfully"), "")

        if infoString[0]:
            level = error and QgsMessageBar.CRITICAL or QgsMessageBar.INFO
            msg = "<b>%s:</b>%s" % (infoString[0], infoString[1])
            iface.pluginManagerInterface().pushMessage(msg, level)

def ActivatePlugins():
    ''' Loading the plugins (we avoid errors).'''
    for plugin in available_plugins:
        if not isPluginLoaded(plugin) and plugin != 'CustomToolBar':
            try:
                loadPlugin(plugin)
                startPlugin(plugin)
            except Exception:
                pass
    return

def installFromZipFile(pluginPath):
    """Install and activate plugin from the specified package
    """
    result = None

    with zipfile.ZipFile(pluginPath, 'r') as zf:
        pluginName = os.path.split(zf.namelist()[0])[0]

    pluginFileName = os.path.splitext(os.path.basename(pluginPath))[0]

    pluginsDirectory = home_plugin_path
    if not QDir(pluginsDirectory).exists():
        QDir().mkpath(pluginsDirectory)

    # If the target directory already exists as a link,
    # remove the link without resolving
    QFile(os.path.join(pluginsDirectory, pluginFileName)).remove()

    try:
        # Test extraction. If fails, then exception will be raised
        # and no removing occurs
        unzip(unicode(pluginPath), unicode(pluginsDirectory))
        # Removing old plugin files if exist
        removeDir(QDir.cleanPath(os.path.join(pluginsDirectory, pluginFileName)))
        # Extract new files
        unzip(unicode(pluginPath), unicode(pluginsDirectory))
    except:
        result = QCoreApplication.translate('BoundlessConnect',
            'Failed to unzip the plugin package\n{}.\nProbably it is broken'.format(pluginPath))

    if result is None:
        updateAvailablePlugins()
        loadPlugin(pluginName)
        plugins.getAllInstalled(testLoad=True)
        plugins.rebuild()
        plugin = plugins.all()[pluginName]

        settings = QSettings()
        if settings.contains('/PythonPlugins/' + pluginName):
            if settings.value('/PythonPlugins/' + pluginName, False, bool):
                startPlugin(pluginName)
                reloadPlugin(pluginName)
            else:
                unloadPlugin(pluginName)
                loadPlugin(pluginName)
        else:
            if startPlugin(pluginName):
                settings.setValue('/PythonPlugins/' + pluginName, True)

    return result

    def __init__(self):
        """ Initialize data objects, starts fetching if appropriate, and warn about/removes obsolete plugins """

        QObject.__init__(self)  # initialize QObject in order to to use self.tr()
        repositories.load()
        plugins.getAllInstalled()

        if repositories.checkingOnStart() and repositories.timeForChecking() and repositories.allEnabled():
            # start fetching repositories
            self.statusLabel = QLabel(self.tr("Looking for new plugins...") + " ", iface.mainWindow().statusBar())
            iface.mainWindow().statusBar().insertPermanentWidget(0, self.statusLabel)
            self.statusLabel.linkActivated.connect(self.showPluginManagerWhenReady)
            repositories.checkingDone.connect(self.checkingDone)
            for key in repositories.allEnabled():
                repositories.requestFetching(key)
        else:
            # no fetching at start, so mark all enabled repositories as requesting to be fetched.
            for key in repositories.allEnabled():
                repositories.setRepositoryData(key, "state", 3)

        # look for obsolete plugins (the user-installed one is newer than core one)
        for key in plugins.obsoletePlugins:
            plugin = plugins.localCache[key]
            msg = QMessageBox()
            msg.setIcon(QMessageBox.Warning)
            msg.setWindowTitle(self.tr("QGIS Python Plugin Installer"))
            msg.addButton(self.tr("Uninstall (recommended)"), QMessageBox.AcceptRole)
            msg.addButton(self.tr("I will uninstall it later"), QMessageBox.RejectRole)
            msg.setText(
                "%s <b>%s</b><br/><br/>%s"
                % (
                    self.tr("Obsolete plugin:"),
                    plugin["name"],
                    self.tr(
                        "QGIS has detected an obsolete plugin that masks its more recent version shipped with this copy of QGIS. This is likely due to files associated with a previous installation of QGIS. Do you want to remove the old plugin right now and unmask the more recent version?"
                    ),
                )
            )
            msg.exec_()
            if not msg.result():
                # uninstall, update utils and reload if enabled
                self.uninstallPlugin(key, quiet=True)
                updateAvailablePlugins()
                settings = QSettings()
                if settings.value("/PythonPlugins/" + key, False, type=bool):
                    settings.setValue("/PythonPlugins/watchDog/" + key, True)
                    loadPlugin(key)
                    startPlugin(key)
                    settings.remove("/PythonPlugins/watchDog/" + key)

def upgradeInstalledPlugins():
    installer = pyplugin_installer.instance()
    initPluginManager(installer)

    errors = []
    pluginsList = plugins.all().copy()
    for plugin in pluginsList:
        if isBoundlessPlugin(pluginsList[plugin]):
            if pluginsList[plugin]['installed'] and pluginsList[plugin]['status'] == 'upgradeable':
                dlg = QgsPluginInstallerInstallingDialog(iface.mainWindow(), plugins.all()[plugin])
                dlg.exec_()
                if dlg.result():
                    errors.append(dlg.result())
                else:
                    updateAvailablePlugins()
                    loadPlugin(plugins.all()[plugin]['id'])
                    plugins.getAllInstalled(testLoad=True)
                    plugins.rebuild()
                    if not plugins.all()[plugin]["error"]:
                        if startPlugin(plugins.all()[plugin]['id']):
                            settings = QSettings()
                            settings.setValue('/PythonPlugins/' + plugins.all()[plugin]['id'], True)

    installer.exportPluginsToManager()
    return errors

def installAllFromRepository():
    """Install Boundless plugins from remote repository
    """
    installer = pyplugin_installer.instance()
    initPluginManager(installer)

    errors = []
    pluginsList = plugins.all().copy()
    for plugin in pluginsList:
        if isBoundlessPlugin(pluginsList[plugin]):
            if (pluginsList[plugin]['installed'] and pluginsList[plugin]['deprecated']) or \
                    not pluginsList[plugin]['deprecated'] and \
                    pluginsList[plugin]["zip_repository"] != '':
                dlg = QgsPluginInstallerInstallingDialog(iface.mainWindow(), plugins.all()[plugin])
                dlg.exec_()
                if dlg.result():
                    errors.append(dlg.result())
                else:
                    updateAvailablePlugins()
                    loadPlugin(plugins.all()[plugin]['id'])
                    plugins.getAllInstalled(testLoad=True)
                    plugins.rebuild()
                    if not plugins.all()[plugin]["error"]:
                        if startPlugin(plugins.all()[plugin]['id']):
                            settings = QSettings()
                            settings.setValue('/PythonPlugins/' + plugins.all()[plugin]['id'], True)

    installer.exportPluginsToManager()
    return errors

 def run(self):
   plugin = currentPlugin()
   #update the plugin list first! The plugin could be removed from the list if was temporarily broken.
   updateAvailablePlugins()
   #try to load from scratch the plugin saved in QSettings if not loaded
   if not plugins.has_key(plugin):
     try:
       loadPlugin(plugin)
       startPlugin(plugin)
     except:
       pass
   updateAvailablePlugins()
   #give one chance for correct (not a loop)
   if not plugins.has_key(plugin):
     self.configure()
     plugin = currentPlugin()
   if plugins.has_key(plugin):
     reloadPlugin(plugin)

def applyPlugins(profile):
    if profile.plugins is None:
        return
    toInstall = [p  for p in profile.plugins if p not in utils.available_plugins]
    pluginErrors = []
    for p in toInstall:
        error = installPlugin(p)
        if error:
            pluginErrors.append(error)

    settings = QSettings()

    ignore = list(pluginsToIgnore)
    layers = QgsMapLayerRegistry.instance().mapLayers().values()
    for lyr in layers:
        if lyr.type() == QgsMapLayer.PluginLayer:
            ignore.extend(pluginsWithLayers)
            break

    tounload = [p for p in utils.active_plugins if p not in ignore]
    for p in tounload:
        try:
            unloadPlugin(p)
        except:
            pass
        settings.setValue('/PythonPlugins/' + p, False)

    updateAvailablePlugins()

    for p in profile.plugins:
        if p not in utils.active_plugins and p in utils.available_plugins:
            loadPlugin(p)
            startPlugin(p)
            settings.setValue('/PythonPlugins/' + p, True)
    updateAvailablePlugins()
    updatePluginManager()

    return pluginErrors

    def installPlugin(self, key, quiet=False):
        """ Install given plugin """
        error = False
        infoString = ('', '')
        plugin = plugins.all()[key]
        previousStatus = plugin["status"]
        if not plugin:
            return
        if plugin["status"] == "newer" and not plugin["error"]:  # ask for confirmation if user downgrades an usable plugin
            if QMessageBox.warning(iface.mainWindow(), self.tr("QGIS Python Plugin Installer"), self.tr("Are you sure you want to downgrade the plugin to the latest available version? The installed one is newer!"), QMessageBox.Yes, QMessageBox.No) == QMessageBox.No:
                return

        dlg = QgsPluginInstallerInstallingDialog(iface.mainWindow(), plugin)
        dlg.exec_()

        if dlg.result():
            error = True
            infoString = (self.tr("Plugin installation failed"), dlg.result())
        elif not QDir(qgis.utils.home_plugin_path + "/" + key).exists():
            error = True
            infoString = (self.tr("Plugin has disappeared"), self.tr("The plugin seems to have been installed but I don't know where. Probably the plugin package contained a wrong named directory.\nPlease search the list of installed plugins. I'm nearly sure you'll find the plugin there, but I just can't determine which of them it is. It also means that I won't be able to determine if this plugin is installed and inform you about available updates. However the plugin may work. Please contact the plugin author and submit this issue."))
            QApplication.setOverrideCursor(Qt.WaitCursor)
            plugins.getAllInstalled()
            plugins.rebuild()
            self.exportPluginsToManager()
            QApplication.restoreOverrideCursor()
        else:
            QApplication.setOverrideCursor(Qt.WaitCursor)
            # update the list of plugins in plugin handling routines
            updateAvailablePlugins()
            # try to load the plugin
            loadPlugin(plugin["id"])
            plugins.getAllInstalled(testLoad=True)
            plugins.rebuild()
            plugin = plugins.all()[key]
            if not plugin["error"]:
                if previousStatus in ["not installed", "new"]:
                    infoString = (self.tr("Plugin installed successfully"), "")
                    if startPlugin(plugin["id"]):
                        settings = QSettings()
                        settings.setValue("/PythonPlugins/" + plugin["id"], True)
                else:
                    settings = QSettings()
                    if settings.value("/PythonPlugins/" + key, False, type=bool):  # plugin will be reloaded on the fly only if currently loaded
                        reloadPlugin(key)  # unloadPlugin + loadPlugin + startPlugin
                        infoString = (self.tr("Plugin reinstalled successfully"), "")
                    else:
                        unloadPlugin(key)  # Just for a case. Will exit quietly if really not loaded
                        loadPlugin(key)
                        infoString = (self.tr("Plugin reinstalled successfully"), self.tr("Python plugin reinstalled.\nYou need to restart QGIS in order to reload it."))
                if quiet:
                    infoString = (None, None)
                QApplication.restoreOverrideCursor()
            else:
                QApplication.restoreOverrideCursor()
                if plugin["error"] == "incompatible":
                    message = self.tr("The plugin is not compatible with this version of QGIS. It's designed for QGIS versions:")
                    message += " <b>" + plugin["error_details"] + "</b>"
                elif plugin["error"] == "dependent":
                    message = self.tr("The plugin depends on some components missing on your system. You need to install the following Python module in order to enable it:")
                    message += "<b> " + plugin["error_details"] + "</b>"
                else:
                    message = self.tr("The plugin is broken. Python said:")
                    message += "<br><b>" + plugin["error_details"] + "</b>"
                dlg = QgsPluginInstallerPluginErrorDialog(iface.mainWindow(), message)
                dlg.exec_()
                if dlg.result():
                    # revert installation
                    pluginDir = qgis.utils.home_plugin_path + "/" + plugin["id"]
                    result = removeDir(pluginDir)
                    if QDir(pluginDir).exists():
                        error = True
                        infoString = (self.tr("Plugin uninstall failed"), result)
                        try:
                            exec ("sys.path_importer_cache.clear()")
                            exec ("import %s" % plugin["id"])
                            exec ("reload (%s)" % plugin["id"])
                        except:
                            pass
                    else:
                        try:
                            exec ("del sys.modules[%s]" % plugin["id"])
                        except:
                            pass
                    plugins.getAllInstalled()
                    plugins.rebuild()

            self.exportPluginsToManager()

        if infoString[0]:
            level = error and QgsMessageBar.CRITICAL or QgsMessageBar.INFO
            msg = "<b>%s:</b>%s" % (infoString[0], infoString[1])
            iface.pluginManagerInterface().pushMessage(msg, level)

    def installFromZipFile(self, filePath):
        if not os.path.isfile(filePath):
            return

        settings = QgsSettings()
        settings.setValue(settingsGroup + '/lastZipDirectory',
                          QFileInfo(filePath).absoluteDir().absolutePath())

        with zipfile.ZipFile(filePath, 'r') as zf:
            pluginName = os.path.split(zf.namelist()[0])[0]

        pluginFileName = os.path.splitext(os.path.basename(filePath))[0]

        pluginsDirectory = qgis.utils.home_plugin_path
        if not QDir(pluginsDirectory).exists():
            QDir().mkpath(pluginsDirectory)

        pluginDirectory = QDir.cleanPath(os.path.join(pluginsDirectory, pluginName))

        # If the target directory already exists as a link,
        # remove the link without resolving
        QFile(pluginDirectory).remove()

        password = None
        infoString = None
        success = False
        keepTrying = True

        while keepTrying:
            try:
                # Test extraction. If fails, then exception will be raised and no removing occurs
                unzip(filePath, pluginsDirectory, password)
                # Removing old plugin files if exist
                removeDir(pluginDirectory)
                # Extract new files
                unzip(filePath, pluginsDirectory, password)
                keepTrying = False
                success = True
            except Exception as e:
                success = False
                if 'password' in str(e):
                    infoString = self.tr('Aborted by user')
                    if 'Bad password' in str(e):
                        msg = self.tr('Wrong password. Please enter a correct password to the zip file.')
                    else:
                        msg = self.tr('The zip file is encrypted. Please enter password.')
                    # Display a password dialog with QgsPasswordLineEdit
                    dlg = QDialog()
                    dlg.setWindowTitle(self.tr('Enter password'))
                    buttonBox = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel, Qt.Horizontal)
                    buttonBox.rejected.connect(dlg.reject)
                    buttonBox.accepted.connect(dlg.accept)
                    lePass = QgsPasswordLineEdit()
                    layout = QVBoxLayout()
                    layout.addWidget(QLabel(msg))
                    layout.addWidget(lePass)
                    layout.addWidget(buttonBox)
                    dlg.setLayout(layout)
                    keepTrying = dlg.exec_()
                    password = lePass.text()
                else:
                    infoString = self.tr("Failed to unzip the plugin package\n{}.\nProbably it is broken".format(filePath))
                    keepTrying = False

        if success:
            updateAvailablePlugins()
            loadPlugin(pluginName)
            plugins.getAllInstalled()
            plugins.rebuild()
            self.exportPluginsToManager()

            if settings.contains('/PythonPlugins/' + pluginName):
                if settings.value('/PythonPlugins/' + pluginName, False, bool):
                    startPlugin(pluginName)
                    reloadPlugin(pluginName)
                else:
                    unloadPlugin(pluginName)
                    loadPlugin(pluginName)
            else:
                if startPlugin(pluginName):
                    settings.setValue('/PythonPlugins/' + pluginName, True)

            msg = "<b>%s</b>" % self.tr("Plugin installed successfully")
        else:
            msg = "<b>%s:</b> %s" % (self.tr("Plugin installation failed"), infoString)

        level = Qgis.Info if success else Qgis.Critical
        iface.pluginManagerInterface().pushMessage(msg, level)

  def installPlugin(self, key, quiet=False):
    """ install currently selected plugin """
    infoString = ('','')
    plugin = plugins.all()[key]
    previousStatus = plugin["status"]
    if not plugin:
      return
    if plugin["status"] == "newer" and not plugin["error"]: # ask for confirmation if user downgrades an usable plugin
      if QMessageBox.warning(self, self.tr("QGIS Python Plugin Installer"), self.tr("Are you sure you want to downgrade the plugin to the latest available version? The installed one is newer!"), QMessageBox.Yes, QMessageBox.No) == QMessageBox.No:
        return
    
    dlg = QgsPluginInstallerInstallingDialog(self,plugin)
    dlg.exec_()

    if dlg.result():
      infoString = (self.tr("Plugin installation failed"), dlg.result())
    elif not QDir(QDir.cleanPath(QgsApplication.qgisSettingsDirPath() + "/python/plugins/" + key)).exists():
      infoString = (self.tr("Plugin has disappeared"), self.tr("The plugin seems to have been installed but I don't know where. Probably the plugin package contained a wrong named directory.\nPlease search the list of installed plugins. I'm nearly sure you'll find the plugin there, but I just can't determine which of them it is. It also means that I won't be able to determine if this plugin is installed and inform you about available updates. However the plugin may work. Please contact the plugin author and submit this issue."))
      QApplication.setOverrideCursor(Qt.WaitCursor)
      plugins.getAllInstalled()
      plugins.rebuild()
      QApplication.restoreOverrideCursor()
    else:
      if QGIS_14:
        if QGIS_15: # update the list of plugins in plugin handling routines
          updateAvailablePlugins()
        # try to load the plugin
        loadPlugin(plugin["localdir"])
      else: # QGIS < 1.4
        try:
          exec ("sys.path_importer_cache.clear()")
          exec ("import %s" % plugin["localdir"])
          exec ("reload (%s)" % plugin["localdir"])
        except:
          pass
      plugins.getAllInstalled(testLoad=True)
      plugins.rebuild()
      plugin = plugins.all()[key]
      if not plugin["error"]:
        if previousStatus in ["not installed", "new"]:
          if QGIS_14: # plugins can be started in python from QGIS >= 1.4
            infoString = (self.tr("Plugin installed successfully"), self.tr("Plugin installed successfully"))
            settings = QSettings()
            settings.setValue("/PythonPlugins/"+plugin["localdir"], QVariant(True))
            startPlugin(plugin["localdir"])
          else: infoString = (self.tr("Plugin installed successfully"), self.tr("Python plugin installed.\nNow you need to enable it in Plugin Manager."))
        else:
          if QGIS_15: # plugins can be reloaded on the fly in QGIS  >= 1.5
            settings = QSettings()
            if key != 'plugin_installer' and settings.value("/PythonPlugins/"+key).toBool(): # plugin will be reloaded on the fly only if currently loaded
              infoString = (self.tr("Plugin reinstalled successfully"), self.tr("Plugin reinstalled successfully"))
              reloadPlugin(key)
            else:
              infoString = (self.tr("Plugin reinstalled successfully"), self.tr("Python plugin reinstalled.\nYou need to restart Quantum GIS in order to reload it."))
          else: infoString = (self.tr("Plugin reinstalled successfully"), self.tr("Python plugin reinstalled.\nYou need to restart Quantum GIS in order to reload it."))
        if quiet:
          infoString = (None, None)
      else:
        if plugin["error"] == "incompatible":
          message = self.tr("The plugin is designed for a newer version of Quantum GIS. The minimum required version is:")
          message += " <b>" + plugin["error_details"] + "</b>"
        elif plugin["error"] == "dependent":
          message = self.tr("The plugin depends on some components missing on your system. You need to install the following Python module in order to enable it:")
          message += "<b> " + plugin["error_details"] + "</b>"
        else:
          message = self.tr("The plugin is broken. Python said:")
          message += "<br><b>" + plugin["error_details"] + "</b>"
        dlg = QgsPluginInstallerPluginErrorDialog(self,message)
        dlg.exec_()
        if dlg.result():
          # revert installation
          plugins.getAllInstalled()
          plugins.rebuild()
          pluginDir = QFileInfo(QgsApplication.qgisUserDbFilePath()).path() + "/python/plugins/" + plugin["localdir"]
          removeDir(pluginDir)
          if QDir(pluginDir).exists():
            infoString = (self.tr("Plugin uninstall failed"), result)
            try:
              exec ("sys.path_importer_cache.clear()")
              exec ("import %s" % plugin["localdir"])
              exec ("reload (%s)" % plugin["localdir"])
            except:
              pass
          else:
            try:
              exec ("del sys.modules[%s]" % plugin["localdir"])
            except:
              pass
          plugins.getAllInstalled()
          plugins.rebuild()
    if plugins.all().has_key(key) and not plugins.all()[key]["status"] in ["not installed", "new"]:
      if previousStatus in ["not installed", "new"]:
        history.markChange(key,'A')
      else:
        history.markChange(key,'R')

    self.populatePluginTree()
    if infoString[0]:
      QMessageBox.information(self, infoString[0], infoString[1])

# Sample script for QGIS Init Script
# This script will install the HelloWorld plugin into user space (if not yet installed)
# The plugin will also be enabled.

import os
import zipfile

from qgis.PyQt.QtCore import QSettings
from qgis.utils import home_plugin_path, loadPlugin, startPlugin, plugins
from qgis.core import QgsMessageLog, Qgis
QgsMessageLog.logMessage("Init script: %s" % __file__, tag="Init script", level=Qgis.Info)

if "HelloWorld" not in plugins:
    # Installing
    zip_ref = zipfile.ZipFile(os.path.join(os.path.dirname(os.path.realpath(__file__)), 'test_data', 'helloworld.zip'), 'r')
    zip_ref.extractall(home_plugin_path)
    zip_ref.close()
    loadPlugin('HelloWorld')
    startPlugin('HelloWorld')
    QgsMessageLog.logMessage("Plugin HelloWorld has been successfully installed", tag="Init script", level=Qgis.Info)
else:
    QgsMessageLog.logMessage("Plugin HelloWorld has been already installed", tag="Init script", level=Qgis.Info)