Error handling.

rtv/content.py

@@ -4,6 +4,8 @@ from contextlib import contextmanager
 
 import praw
 
+from errors import SubmissionURLError, SubredditNameError
+
 def clean(unicode_string):
     """
     Convert unicode string into ascii-safe characters.
@@ -159,8 +161,12 @@ class SubmissionContent(BaseContent):
             indent_size=2,
             max_indent_level=4):
 
-        with loader():
-            submission = reddit.get_submission(url)
+        try:
+            with loader():
+                submission = reddit.get_submission(url)
+
+        except praw.errors.APIException:
+            raise SubmissionURLError(url)
 
         return cls(submission, loader, indent_size, max_indent_level)
 
@@ -273,9 +279,13 @@ class SubredditContent(BaseContent):
 
         if name == 'all':
             sub = reddit.get_subreddit(name)
+
         else:
-            with loader():
-                sub = reddit.get_subreddit(name, fetch=True)
+            try:
+                with loader():
+                    sub = reddit.get_subreddit(name, fetch=True)
+            except praw.errors.ClientException:
+                raise SubredditNameError(name)
 
         return cls('/r/'+sub.display_name, sub.get_hot(limit=None), loader)
 

rtv/errors.py

@@ -0,0 +1,12 @@
+class EscapePressed(Exception):
+    pass
+
+class SubmissionURLError(Exception):
+
+    def __init__(self, url):
+        self.url = url
+
+class SubredditNameError(Exception):
+
+    def __init__(self, name):
+        self.name = name

rtv/main.py

@@ -1,30 +1,58 @@
 import argparse
 import praw
+from requests.exceptions import ConnectionError
 
+from errors import SubmissionURLError, SubredditNameError
 from utils import curses_session
 from subreddit import SubredditPage
+from submission import SubmissionPage
 
 parser = argparse.ArgumentParser(description='Reddit Terminal Viewer')
 parser.add_argument('-s', dest='subreddit', default='front', help='subreddit name')
-parser.add_argument('-l', dest='link', help='full link to a specific submission')
+parser.add_argument('-l', dest='link', help='full link to a submission')
 group = parser.add_argument_group('authentication (optional)')
 group.add_argument('-u', dest='username', help='reddit username')
 group.add_argument('-p', dest='password', help='reddit password')
+group.add_argument('--debug', action='store_true')
 
 def main(args):
 
-    reddit = praw.Reddit(user_agent='reddit terminal viewer v0.0')
-    reddit.config.decode_html_entities = True
+    try:
+        reddit = praw.Reddit(user_agent='reddit terminal viewer v0.0')
+        reddit.config.decode_html_entities = True
 
-    if args.username and args.password:
-        reddit.login(args.username, args.password)
+        if args.username and args.password:
+            reddit.login(args.username, args.password)
 
-    with curses_session() as stdscr:
+        with curses_session() as stdscr:
 
-        page = SubredditPage(stdscr, reddit, args.subreddit)
-        page.loop()
+                if args.link:
+                    # Go directly to submission
+                    page = SubmissionPage(stdscr, reddit, url=args.link)
+                    page.loop()
+
+                page = SubredditPage(stdscr, reddit, args.subreddit)
+                page.loop()
+
+    except KeyboardInterrupt:
+        return
+
+    except ConnectionError:
+        print 'Timeout: Could not connect to website'
+
+    except SubmissionURLError as e:
+        print 'Could not reach submission URL: {}'.format(e.url)
+
+    except SubredditNameError as e:
+        print 'Could not reach subreddit: {}'.format(e.name)
+
+    # except Exception:
+    #     if not args.debug:
+    #         print 'Unhandled exception'
+    #     else:
+    #         raise
 
 if __name__ == '__main__':
 
     args = parser.parse_args()
-    main(args)
+    main(args)

rtv/page.py

@@ -75,6 +75,9 @@ class BasePage(object):
     Base terminal viewer incorperates a cursor to navigate content
     """
 
+    MIN_HEIGHT = 10
+    MIN_WIDTH = 20
+
     def __init__(self, stdscr, content, **kwargs):
 
         self.stdscr = stdscr
@@ -107,21 +110,27 @@ class BasePage(object):
     def draw(self):
 
         n_rows, n_cols = self.stdscr.getmaxyx()
+        if n_rows < self.MIN_HEIGHT or n_cols < self.MIN_WIDTH:
+            return
+
         self._header_window = self.stdscr.derwin(1, n_cols, 0, 0)
         self._content_window = self.stdscr.derwin(1, 0)
 
-        self.draw_header()
-        self.draw_content()
+        self._draw_header()
+        self._draw_content()
         self.add_cursor()
 
-    def draw_header(self):
+    def draw_item(self, window, data, inverted):
+        raise NotImplementedError
+
+    def _draw_header(self):
 
         n_rows, n_cols = self._header_window.getmaxyx()
 
         self._header_window.erase()
         self._header_window.addnstr(0, 0, self.content.name, n_cols-1)
 
-    def draw_content(self):
+    def _draw_content(self):
         """
         Loop through submissions and fill up the content page.
         """
@@ -153,9 +162,6 @@ class BasePage(object):
 
         self._content_window.refresh()
 
-    def draw_item(self, window, data, inverted):
-        raise NotImplementedError
-
     def _move_cursor(self, direction):
 
         self.remove_cursor()
@@ -167,7 +173,7 @@ class BasePage(object):
         # If we don't redraw, ACS_VLINE gets screwed up when changing the
         # attr back to normal. There may be a way around this.
         if True: #if redraw
-            self.draw_content()
+            self._draw_content()
 
         self.add_cursor()
 

rtv/subreddit.py

@@ -1,10 +1,11 @@
 import curses
 import sys
 
+from errors import SubredditNameError
 from page import BasePage
 from submission import SubmissionPage
 from content import SubredditContent
-from utils import LoadScreen, text_input
+from utils import LoadScreen, text_input, display_message
 
 class SubredditPage(BasePage):
 
@@ -56,11 +57,21 @@ class SubredditPage(BasePage):
 
     def refresh_content(self, name=None):
 
-        self.nav.page_index, self.nav.cursor_index = 0, 0
-        self.nav.inverted = False
-        self.name = name if name else self.name
-        self.content = SubredditContent.from_name(self.reddit, self.name, self.loader)
-        self.stdscr.clear()
+        name = name or self.name
+
+        try:
+            self.content = SubredditContent.from_name(
+                self.reddit, name, self.loader)
+
+        except SubredditNameError:
+            display_message(self.stdscr, 'Invalid Subreddit')
+
+        else:
+            self.nav.page_index, self.nav.cursor_index = 0, 0
+            self.nav.inverted = False
+            self.name = name
+
+        #self.stdscr.clear()
         self.draw()
 
     def prompt_subreddit(self):

rtv/utils.py

@@ -5,8 +5,7 @@ import threading
 from curses import textpad
 from contextlib import contextmanager
 
-class EscapePressed(Exception):
-    pass
+from errors import EscapePressed
 
 def text_input(window):
     """
@@ -40,6 +39,27 @@ def text_input(window):
     return out
 
 
+def display_message(stdscr, message):
+    "Display a message box at the center of the screen and wait for a keypress"
+
+    message_len = len(message)
+    n_rows, n_cols = stdscr.getmaxyx()
+    s_row = (n_rows - 2) / 2
+    s_col = (n_cols - message_len - 1) / 2
+    window = stdscr.derwin(3, message_len+2, s_row, s_col)
+
+    window.erase()
+    window.border()
+    window.addstr(1, 1, message)
+    window.refresh()
+
+    stdscr.getch()
+
+    window.clear()
+    window = None
+    stdscr.refresh()
+
+
 class LoadScreen(object):
 
     def __init__(self, stdscr):