Refactor IdeHandler

tfw/components/ide/ide_handler.py

@@ -1,5 +1,4 @@
 import logging
-from os.path import isfile
 
 from tfw.internals.networking import Scope
 from tfw.internals.inotify import InotifyObserver
@@ -36,10 +35,10 @@ class IdeHandler:
     keys = ['ide']
     type_id = 'ControlEventHandler'
 
-    def __init__(self, *, patterns, initial_file=''):
+    def __init__(self, *, patterns, initial_file=None):
         self.connector = None
         self.filemanager = FileManager(patterns)
-        self._initial_file = initial_file
+        self._initial_file = initial_file or ''
 
         self.monitor = InotifyObserver(
             path=self.filemanager.parents,
@@ -53,46 +52,48 @@ class IdeHandler:
             'ide.write' : self.write
         }
 
-    @property
-    def initial_file(self):
-        if not isfile(self._initial_file):
-            self._initial_file = self.filemanager.files[0]
-        return self._initial_file
-
     def _reload_frontend(self, event):  # pylint: disable=unused-argument
         self.send_message({'key': 'ide.reload'})
 
+    @property
+    def initial_file(self):
+        if not self.filemanager.is_allowed(self._initial_file):
+            self._initial_file = self.filemanager.files[0]
+        return self._initial_file
+
     def send_message(self, message):
         self.connector.send_message(message, scope=Scope.WEBSOCKET)
 
-    def read(self, message):
-        if message.get('files'):
-            self.filemanager.patterns = message['files']
-        try:
-            message['content'] = self.filemanager.read_file(message['filename'])
-        except PermissionError:
-            message['content'] = 'You have no permission to open that file :('
-        except FileNotFoundError:
-            message['content'] = 'This file was removed :('
-        except Exception: # pylint: disable=broad-except
-            message['content'] = 'Failed to read file :('
-
-    def write(self, message):
-        try:
-            self.filemanager.write_file(message['filename'], message['content'])
-        except Exception: # pylint: disable=broad-except
-            LOG.exception('Error writing file!')
-        del message['content']
-
     def handle_event(self, message, _):
         try:
-            if message['filename'] == '':
-                message['filename'] = self.initial_file
             self.commands[message['key']](message)
             message['files'] = self.filemanager.files
             self.send_message(message)
         except KeyError:
             LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)
 
+    def read(self, message):
+        if message.get('files'):
+            self.filemanager.patterns = message['files']
+        try:
+            message['filename'] = message.get('filename') or self.initial_file
+            message['content'] = self.filemanager.read_file(message['filename'])
+        except (PermissionError, ValueError):
+            message['content'] = 'You have no permission to open that file :('
+        except FileNotFoundError:
+            message['content'] = 'This file does not exist :('
+        except Exception: # pylint: disable=broad-except
+            message['content'] = 'Failed to read file :('
+            LOG.exception('Error reading file!')
+
+    def write(self, message):
+        try:
+            self.filemanager.write_file(message['filename'], message['content'])
+        except KeyError:
+            LOG.error('You must provide a filename to write!')
+        except Exception: # pylint: disable=broad-except
+            LOG.exception('Error writing file!')
+        del message['content']
+
     def cleanup(self):
         self.monitor.stop()