[core/module] Add error widgets if a module throws

Module should have to care less about thrown exceptions.

bumblebee-status

@@ -46,7 +46,7 @@ def main():
 
     config = core.config.Config(sys.argv[1:])
     theme = core.theme.Theme(config.theme(), config.iconset())
-    output = core.output.i3(theme)
+    output = core.output.i3(theme, config)
     modules = []
 
     input_thread = threading.Thread(target=handle_input, args=(output,))

core/module.py

@@ -38,6 +38,14 @@ class Module(core.input.Object):
     def update(self):
         pass
 
+    def update_wrapper(self):
+        try:
+            self.update()
+        except Exception as e:
+            module = Error(self._config, 'error', str(e))
+            self._widgets = [module.widgets()[0]]
+            self.update = module.update
+
     def name(self):
         return self._name if self._name else self.module_name()
 

core/output.py

@@ -6,14 +6,20 @@ import core.theme
 import core.event
 
 class i3(object):
-    def __init__(self, theme=core.theme.Theme()):
+    def __init__(self, theme=core.theme.Theme(), config=None):
         self._modules = []
         self._status = {}
         self._theme = theme
+        self._config = config
         core.event.register('start', self.draw, 'start')
         core.event.register('update', self.draw, 'statusline')
         core.event.register('stop', self.draw, 'stop')
 
+    def theme(self, new_theme=None):
+        if new_theme:
+            self._theme = new_theme
+        return self._theme
+
     def modules(self, modules=None):
         if not modules:
             return self._modules
@@ -96,7 +102,7 @@ class i3(object):
         for module in self._modules:
             if affected_modules and not module.id() in affected_modules:
                 continue
-            module.update()
+            module.update_wrapper()
             for widget in module.widgets():
                 self._status[widget] = widget.full_text()
 

core/widget.py

@@ -1,4 +1,5 @@
 import core.input
+import core.decorators
 import util.store
 
 class Widget(util.store.Store, core.input.Object):

doc/NOTES.md

@@ -23,5 +23,5 @@
 
 ## Improvements
 - pango output (improve - maybe autodetect? see #531)
-- only update specific, affected modules when clicking
 - allow handlers to specify whether to update or not (e.g. scroll)
+- error handling: don't catch too many exceptions in a module (pulseaudio!), instead, propagate them as error widgets

tests/core/test_module.py

@@ -26,11 +26,20 @@ class module(unittest.TestCase):
         module = core.module.load(module_name=self.validModuleName)
         self.assertEqual('modules.{}'.format(self.validModuleName), module.__class__.__module__, 'module must be a modules.<name> object')
         self.assertEqual('Module', module.__class__.__name__, 'a valid module must have a Module class')
+        self.assertEqual([], module.state(None), 'default state of module is empty')
 
     def test_empty_widgets(self):
         module = core.module.Module(widgets=[])
         self.assertEqual([], module.widgets())
 
+    def test_error_widget(self):
+        cfg = core.config.Config(shlex.split('-p test_module.foo=5'))
+        module = core.module.Error(cfg, 'test-mod', 'xyz')
+        self.assertEqual(['critical'], module.state(None), 'error module must have critical state')
+        full_text = module.full_text(module.widgets()[0])
+        self.assertTrue('test-mod' in full_text)
+        self.assertTrue('xyz' in full_text)
+
     def test_single_widget(self):
         module = core.module.Module(widgets=self.someWidget)
         self.assertEqual([self.someWidget], module.widgets())

tests/core/test_output.py

@@ -13,6 +13,9 @@ class i3(unittest.TestCase):
         widget = unittest.mock.MagicMock()
         widget.full_text.return_value = "test"
         self.someModule = TestModule(widgets=[widget, widget, widget])
+        self.paddedTheme = core.theme.Theme(raw_data = {
+            'defaults': { 'padding': ' ' }
+        });
 
     def test_start(self):
         core.event.clear()
@@ -55,4 +58,9 @@ class i3(unittest.TestCase):
         data = self.i3.statusline()
         self.assertEqual(len(self.someModule.widgets())*3, len(data['data']), 'wrong number of widgets')
 
+    def test_padding(self):
+        self.i3.theme(self.paddedTheme)
+        result = self.i3.__pad(self.someModule, self.someModule.widgets()[0], 'abc')
+        self.assertEqual(' abc ', result)
+
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