better code organization

function parameters should be lowercase

Fix crash on invalid labels import

Added invoice exporting and reduced duplicate code

Better exception handling

removed json module import

some more cleanup

Cleaned up some stuff

Added exporting contacts

gui/qt/contact_list.py

@@ -23,16 +23,17 @@
 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 # SOFTWARE.
 import webbrowser
+import os
 
 from electrum.i18n import _
 from electrum.bitcoin import is_address
-from electrum.util import block_explorer_URL, FileImportFailed
+from electrum.util import block_explorer_URL
 from electrum.plugins import run_hook
 from PyQt5.QtGui import *
 from PyQt5.QtCore import *
 from PyQt5.QtWidgets import (
     QAbstractItemView, QFileDialog, QMenu, QTreeWidgetItem)
-from .util import MyTreeWidget
+from .util import MyTreeWidget, import_meta_gui, export_meta_gui
 
 
 class ContactList(MyTreeWidget):
@@ -53,15 +54,10 @@ class ContactList(MyTreeWidget):
         self.parent.set_contact(item.text(0), item.text(1))
 
     def import_contacts(self):
-        wallet_folder = self.parent.get_wallet_folder()
-        filename, __ = QFileDialog.getOpenFileName(self.parent, "Select your wallet file", wallet_folder)
-        if not filename:
-            return
-        try:
-            self.parent.contacts.import_file(filename)
-        except FileImportFailed as e:
-            self.parent.show_message(str(e))
-        self.on_update()
+        import_meta_gui(self.parent, _('contacts'), self.parent.contacts.import_file, self.on_update)
+
+    def export_contacts(self):
+        export_meta_gui(self.parent, _('contacts'), self.parent.contacts.export_file)
 
     def create_menu(self, position):
         menu = QMenu()
@@ -69,6 +65,7 @@ class ContactList(MyTreeWidget):
         if not selected:
             menu.addAction(_("New contact"), lambda: self.parent.new_contact_dialog())
             menu.addAction(_("Import file"), lambda: self.import_contacts())
+            menu.addAction(_("Export file"), lambda: self.export_contacts())
         else:
             names = [item.text(0) for item in selected]
             keys = [item.text(1) for item in selected]

gui/qt/invoice_list.py

@@ -25,7 +25,7 @@
 
 from .util import *
 from electrum.i18n import _
-from electrum.util import format_time, FileImportFailed
+from electrum.util import format_time
 
 
 class InvoiceList(MyTreeWidget):
@@ -57,15 +57,10 @@ class InvoiceList(MyTreeWidget):
         self.parent.invoices_label.setVisible(len(inv_list))
 
     def import_invoices(self):
-        wallet_folder = self.parent.get_wallet_folder()
-        filename, __ = QFileDialog.getOpenFileName(self.parent, "Select your wallet file", wallet_folder)
-        if not filename:
-            return
-        try:
-            self.parent.invoices.import_file(filename)
-        except FileImportFailed as e:
-            self.parent.show_message(str(e))
-        self.on_update()
+        import_meta_gui(self.parent, _('invoices'), self.parent.invoices.import_file, self.on_update)
+
+    def export_invoices(self):
+        export_meta_gui(self.parent, _('invoices'), self.parent.invoices.export_file)
 
     def create_menu(self, position):
         menu = QMenu()

gui/qt/main_window.py

@@ -61,7 +61,7 @@ from .fee_slider import FeeSlider
 
 from .util import *
 
-from electrum.util import profiler
+from electrum.util import profiler, export_meta, import_meta
 
 class StatusBarButton(QPushButton):
     def __init__(self, icon, tooltip, func):
@@ -484,8 +484,10 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
         contacts_menu = wallet_menu.addMenu(_("Contacts"))
         contacts_menu.addAction(_("&New"), self.new_contact_dialog)
         contacts_menu.addAction(_("Import"), lambda: self.contact_list.import_contacts())
+        contacts_menu.addAction(_("Export"), lambda: self.contact_list.export_contacts())
         invoices_menu = wallet_menu.addMenu(_("Invoices"))
         invoices_menu.addAction(_("Import"), lambda: self.invoice_list.import_invoices())
+        invoices_menu.addAction(_("Export"), lambda: self.invoice_list.export_invoices())
 
         wallet_menu.addSeparator()
         wallet_menu.addAction(_("Find"), self.toggle_search).setShortcut(QKeySequence("Ctrl+F"))
@@ -2417,29 +2419,23 @@ class ElectrumWindow(QMainWindow, MessageBoxMixin, PrintError):
                 f.write(json.dumps(pklist, indent = 4))
 
     def do_import_labels(self):
-        labelsFile = self.getOpenFileName(_("Open labels file"), "*.json")
-        if not labelsFile: return
-        try:
-            with open(labelsFile, 'r') as f:
-                data = f.read()
-            for key, value in json.loads(data).items():
+        def import_labels(path):
+            #TODO: Import labels validation
+            def import_labels_validate(data):
+                return data
+            def import_labels_assign(data):
+                for key, value in data.items():
                     self.wallet.set_label(key, value)
-            self.show_message(_("Your labels were imported from") + " '%s'" % str(labelsFile))
-        except (IOError, os.error) as reason:
-            self.show_critical(_("Electrum was unable to import your labels.") + "\n" + str(reason))
+            import_meta(path, import_labels_validate, import_labels_assign)
+        def on_import():
             self.address_list.update()
             self.history_list.update()
+        import_meta_gui(self, _('labels'), import_labels, on_import)
 
     def do_export_labels(self):
-        labels = self.wallet.labels
-        try:
-            fileName = self.getSaveFileName(_("Select file to save your labels"), 'electrum_labels.json', "*.json")
-            if fileName:
-                with open(fileName, 'w+') as f:
-                    json.dump(labels, f, indent=4, sort_keys=True)
-                self.show_message(_("Your labels were exported to") + " '%s'" % str(fileName))
-        except (IOError, os.error) as reason:
-            self.show_critical(_("Electrum was unable to export your labels.") + "\n" + str(reason))
+        def export_labels(filename):
+            export_meta(self.wallet.labels, filename)
+        export_meta_gui(self, _('labels'), export_labels)
 
     def sweep_key_dialog(self):
         d = WindowModalDialog(self, title=_('Sweep private keys'))

gui/qt/util.py

@@ -11,6 +11,7 @@ from PyQt5.QtGui import *
 from PyQt5.QtCore import *
 from PyQt5.QtWidgets import *
 
+from electrum.util import FileImportFailed, FileExportFailed
 if platform.system() == 'Windows':
     MONOSPACE_FONT = 'Lucida Console'
 elif platform.system() == 'Darwin':
@@ -674,6 +675,28 @@ class AcceptFileDragDrop:
     def onFileAdded(self, fn):
         raise NotImplementedError()
 
+def import_meta_gui(electrum_window, title, importer, on_success):
+    filename = electrum_window.getOpenFileName(_("Open {} file").format(title)  , "*.json")
+    if not filename:
+       return
+    try:
+       importer(filename)
+    except FileImportFailed as e:
+       electrum_window.show_critical(str(e))
+    else:
+       electrum_window.show_message(_("Your {} were successfully imported" ).format(title))
+       on_success()
+
+def export_meta_gui(electrum_window, title, exporter):
+    filename = electrum_window.getSaveFileName(_("Select file to save your {}").format(title), 'electrum_{}.json'.format(title), "*.json")
+    if  not filename:
+        return
+    try:
+        exporter(filename)
+    except FileExportFailed as e:
+        electrum_window.show_critical(str(e))
+    else:
+        electrum_window.show_message(_("Your {0} were exported to '{1}'").format(title,str(filename)))
 
 if __name__ == "__main__":
     app = QApplication([])

lib/contacts.py

@@ -25,10 +25,11 @@ import dns
 import json
 import traceback
 import sys
+import os
 
 from . import bitcoin
 from . import dnssec
-from .util import FileImportFailed, FileImportFailedEncrypted
+from .util import export_meta, import_meta
 
 
 class Contacts(dict):
@@ -51,18 +52,15 @@ class Contacts(dict):
         self.storage.put('contacts', dict(self))
 
     def import_file(self, path):
-        try:
-            with open(path, 'r') as f:
-                d = self._validate(json.loads(f.read()))
-        except json.decoder.JSONDecodeError:
-            traceback.print_exc(file=sys.stderr)
-            raise FileImportFailedEncrypted()
-        except BaseException:
-            traceback.print_exc(file=sys.stdout)
-            raise FileImportFailed()
-        self.update(d)
+        import_meta(path, self.validate, self.load_meta)
+
+    def load_meta(self, data):
+        self.update(data)
         self.save()
 
+    def export_file(self, fileName):
+        export_meta(self, fileName)
+
     def __setitem__(self, key, value):
         dict.__setitem__(self, key, value)
         self.save()
@@ -119,7 +117,7 @@ class Contacts(dict):
         except AttributeError:
             return None
             
-    def _validate(self, data):
+    def validate(self, data):
         for k,v in list(data.items()):
             if k == 'contacts':
                 return self._validate(v)

lib/paymentrequest.py

@@ -40,7 +40,7 @@ except ImportError:
 from . import bitcoin
 from . import util
 from .util import print_error, bh2u, bfh
-from .util import FileImportFailed, FileImportFailedEncrypted
+from .util import export_meta, import_meta
 from . import transaction
 from . import x509
 from . import rsakey
@@ -468,27 +468,31 @@ class InvoiceStore(object):
                 continue
 
     def import_file(self, path):
-        try:
-            with open(path, 'r') as f:
-                d = json.loads(f.read())
-                self.load(d)
-        except json.decoder.JSONDecodeError:
-            traceback.print_exc(file=sys.stderr)
-            raise FileImportFailedEncrypted()
-        except BaseException:
-            traceback.print_exc(file=sys.stdout)
-            raise FileImportFailed()
+        import_meta(path, self.validate, self.on_import)
+
+    #TODO: Invoice import validation
+    def validate(self, data):
+        return data
+
+    def on_import(self, data):
+        self.load(data)
         self.save()
 
-    def save(self):
-        l = {}
+    def export_file(self, fileName):
+        export_meta(self.before_save(), fileName)
+
+    def before_save(self):
+        l= {}
         for k, pr in self.invoices.items():
             l[k] = {
                 'hex': bh2u(pr.raw),
                 'requestor': pr.requestor,
                 'txid': pr.tx
             }
-        self.storage.put('invoices', l)
+        return l
+
+    def save(self):
+        self.storage.put('invoices', self.before_save())
 
     def get_status(self, key):
         pr = self.get(key)

lib/util.py

@@ -60,16 +60,18 @@ class InvalidPassword(Exception):
 
 
 class FileImportFailed(Exception):
+    def __init__(self, message=''):
+        self.message = str(message)
+
     def __str__(self):
-        return _("Failed to import file.")
+        return _("Failed to import from file.") + "\n" + self.message
 
+class FileExportFailed(Exception):
+    def __init__(self, reason=''):
+        self.message = str(reason)
 
-class FileImportFailedEncrypted(FileImportFailed):
     def __str__(self):
-        return (_('Failed to import file.') + ' ' +
-                _('Perhaps it is encrypted...') + '\n' +
-                _('Importing encrypted files is not supported.'))
-
+        return( _("Failed to export to file.") + "\n" + self.message )
 
 # Throw this exception to unwind the stack like when an error occurs.
 # However unlike other exceptions the user won't be informed.
@@ -785,3 +787,24 @@ def setup_thread_excepthook():
 
 def versiontuple(v):
     return tuple(map(int, (v.split("."))))
+
+def import_meta(path, validater, load_meta):
+    try:
+        with open(path, 'r') as f:
+            d = validater(json.loads(f.read()))
+        load_meta(d)
+    #backwards compatibility for JSONDecodeError
+    except ValueError:
+        traceback.print_exc(file=sys.stderr)
+        raise FileImportFailed(_("Invalid JSON code."))
+    except BaseException as e:
+         traceback.print_exc(file=sys.stdout)
+         raise FileImportFailed(e)
+
+def export_meta(meta, fileName):
+     try:
+         with open(fileName, 'w+') as f:
+            json.dump(meta, f, indent=4, sort_keys=True)
+     except (IOError, os.error) as reason:
+         traceback.print_exc(file=sys.stderr)
+         raise FileExportFailed(str(reason))