Add web app config support.

For #177.

src/reader/_app/__init__.py

@@ -28,9 +28,9 @@
 from reader import Entry
 from reader import EntrySearchResult
 from reader import InvalidSearchQueryError
-from reader import make_reader
 from reader import ParseError
 from reader import ReaderError
+from reader._config import make_reader_from_config
 from reader._plugins import Loader
 from reader._plugins import LoaderError
 
@@ -47,9 +47,10 @@
 
 def get_reader():
     if not hasattr(g, 'reader'):
-        reader = make_reader(current_app.config['READER_DB'])
-        current_app.reader_load_plugins(reader)
-        g.reader = reader
+        g.reader = make_reader_from_config(
+            plugin_loader_cls=FlaskPluginLoader,
+            **current_app.config['READER_CONFIG']['reader'],
+        )
     return g.reader
 
 
@@ -232,8 +233,12 @@ def preview():
     # TODO: maybe redirect to the feed we have if we already have it
 
     # TODO: maybe cache stuff
-    reader = make_reader(':memory:')
-    current_app.reader_load_plugins(reader)
+
+    # TODO: config should have a helper to do this
+    kwargs = current_app.config['READER_CONFIG']['reader'].copy()
+    kwargs['url'] = ':memory:'
+    current_app.config['READER_CONFIG']['reader']
+    reader = make_reader_from_config(**kwargs, plugin_loader_cls=FlaskPluginLoader)
 
     reader.add_feed(url)
 
@@ -439,25 +444,25 @@ def handle_error(self, exception, cause):
         )
 
 
-def create_app(db_path, plugins=(), app_plugins=()):
+def create_app(config):
     app = Flask(__name__)
     app.secret_key = 'secret'
 
-    app.config['READER_DB'] = db_path
+    app.config['READER_CONFIG'] = config
     app.teardown_appcontext(close_db)
 
+    # Force reader plugins to load, so we can fail fast for import errors
+    # (although some errors may just be logged while we use FlaskPluginLoader).
+    with app.app_context():
+        get_reader()
+
     app.register_blueprint(blueprint)
 
     # NOTE: this is part of the app extension API
     app.reader_additional_enclosure_links = []
 
-    app.reader_load_plugins = FlaskPluginLoader(plugins).load_plugins
-    # Force reader plugins to load, so we can fail fast for import errors.
-    with app.app_context():
-        get_reader()
-
     # app_context() needed for logging to work.
     with app.app_context():
-        FlaskPluginLoader(app_plugins).load_plugins(app)
+        FlaskPluginLoader(config.get('app', {}).get('plugins', {})).load_plugins(app)
 
     return app

src/reader/_app/cli.py

@@ -29,9 +29,5 @@ def serve(config, host, port, plugin, verbose):
     config['app'] = merge_config(default_options, config['app'], user_options)
 
     # FIXME: once create_app knows how to work from config, change these
-    app = create_app(
-        config['reader']['url'],
-        tuple(config['reader'].get('plugins', ())),
-        tuple(config['app'].get('plugins', ())),
-    )
+    app = create_app(config)
     run_simple(host, port, app)

src/reader/_app/templates/layout.html

@@ -23,7 +23,9 @@
 position: fixed;
 bottom: 0;
 right: 0;
-"><code>{{ config.READER_DB }}</code></p>
+"
+title='{{ config.READER_CONFIG | tojson(indent=4) | escape }}'
+><code>{{ config.READER_CONFIG.reader.url }}</code></p>
 {% endif %}
 
 

src/reader/_app/wsgi.py

@@ -3,19 +3,40 @@
 To run a local development server:
 
     FLASK_DEBUG=1 FLASK_TRAP_BAD_REQUEST_ERRORS=1 \
-    FLASK_APP=src/reader/app/wsgi.py \
-    READER_DB=db.sqlite flask run -h 0.0.0.0 -p 8000
+    FLASK_APP=src/reader/_app/wsgi.py \
+    READER_CONFIG=examples/config.yaml READER_DB=db.sqlite \
+    flask run -h 0.0.0.0 -p 8000
 
 """
 import os
 
 import reader._app
+import reader._config
 
-app = reader._app.create_app(
-    os.environ[reader._DB_ENVVAR],
-    os.environ.get(reader._PLUGIN_ENVVAR, '').split(),
-    os.environ.get(reader._APP_PLUGIN_ENVVAR, '').split(),
+
+# TODO: this if is for compatibility only, remove after config is released
+if reader._CONFIG_ENVVAR in os.environ:
+    with open(os.environ[reader._CONFIG_ENVVAR]) as file:
+        config = reader._config.load_config(file)
+else:
+    config = reader._config.load_config({'reader': {}, 'app': {}})
+
+
+# TODO: this is for compatibility only, remove after config is released
+user_config = {'reader': {}, 'app': {}}
+if reader._DB_ENVVAR in os.environ:
+    user_config['reader']['url'] = os.environ[reader._DB_ENVVAR]
+user_config['reader']['plugins'] = dict.fromkeys(
+    os.environ.get(reader._PLUGIN_ENVVAR, '').split()
 )
+user_config['app']['plugins'] = dict.fromkeys(
+    os.environ.get(reader._APP_PLUGIN_ENVVAR, '').split()
+)
+for key in 'reader', 'app':
+    config[key] = reader._config.merge_config(config[key], user_config[key])
+
+
+app = reader._app.create_app(config)
 app.config['TRAP_BAD_REQUEST_ERRORS'] = bool(
     os.environ.get('FLASK_TRAP_BAD_REQUEST_ERRORS', '')
 )

src/reader/_config.py

@@ -15,7 +15,7 @@
 MERGE_KWARGS = ('plugins',)
 
 
-def make_reader_from_config(*, plugins=None, **kwargs):
+def make_reader_from_config(*, plugins=None, plugin_loader_cls=Loader, **kwargs):
     """Like reader.make_reader(), but:
 
     * If *_cls arguments are str, import them.
@@ -32,7 +32,7 @@ def make_reader_from_config(*, plugins=None, **kwargs):
     reader = make_reader(**kwargs)
 
     try:
-        Loader(plugins).load_plugins(reader)
+        plugin_loader_cls(plugins).load_plugins(reader)
     except Exception:
         reader.close()
         raise

tests/test_app.py

@@ -8,11 +8,12 @@
 
 from reader import make_reader
 from reader._app import create_app
+from reader._config import make_reader_from_config
 
 
 @pytest.fixture
 def browser(db_path):
-    app = create_app(db_path)
+    app = create_app({'reader': {'url': db_path}})
     session = requests.Session()
     session.mount('http://app/', wsgiadapter.WSGIAdapter(app))
     browser = mechanicalsoup.StatefulBrowser(session)
@@ -99,15 +100,15 @@ def test_add_delete_feed(db_path, browser, monkeypatch):
     feed = parser.feed(1, datetime(2010, 1, 1))
     entry = parser.entry(1, 1, datetime(2010, 1, 1))
 
-    def app_make_reader(db_path):
-        reader = make_reader(db_path)
+    def app_make_reader(**kwargs):
+        reader = make_reader_from_config(**kwargs)
         reader._parser = parser
         return reader
 
     # this is brittle, it may break if we change how we use make_reader in app
-    monkeypatch.setattr('reader._app.make_reader', app_make_reader)
+    monkeypatch.setattr('reader._app.make_reader_from_config', app_make_reader)
 
-    reader = app_make_reader(db_path)
+    reader = app_make_reader(url=db_path)
 
     browser.open('http://app/')
     response = browser.follow_link(browser.find_link(text='feeds'))

tests/test_cli.py

@@ -174,14 +174,16 @@ def test_cli_serve_calls_create_app(db_path, monkeypatch):
 
     exception = Exception("create_app error")
 
-    def create_app(*args):
-        assert args == (db_path, (), ())
+    def create_app(config):
+        create_app.config = config
         raise exception
 
     monkeypatch.setattr('reader._app.create_app', create_app)
 
     runner = CliRunner()
-    result = runner.invoke(cli, ['--db', db_path, 'serve'])
 
-    assert result.exit_code != 0
-    assert result.exception == exception
+    with pytest.raises(Exception) as excinfo:
+        runner.invoke(cli, ['--db', db_path, 'serve'], catch_exceptions=False)
+
+    assert excinfo.value is exception
+    assert create_app.config == {'reader': {'url': db_path}, 'app': {}, 'cli': {}}