Add filters for og & fg

src/humulus/app.py

@@ -46,4 +46,8 @@ def create_app(test_config=None):
     from . import auth
     app.register_blueprint(auth.bp)
 
+    # Register custom filters
+    from . import filters
+    filters.create_filters(app)
+
     return app

src/humulus/filters.py

@@ -0,0 +1,68 @@
+"""This module contains filters used in rendering of Jinja templates."""
+
+# Copyright 2019 Mike Shoup
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def recipe_og(recipe):
+    """Returns a recipe's Original Gravity"""
+    points = 0
+    grain_points = 0
+    # Loop through fermentables, adding up points
+    for fermentable in recipe['fermentables']:
+        if fermentable['type'] == 'Grain':
+            grain_points += (
+                float(fermentable['amount']) * float(fermentable['ppg'])
+            )
+        else:
+            points += (
+                float(fermentable['amount']) * float(fermentable['ppg'])
+            )
+    points += grain_points * float(recipe['efficiency']) / 100
+    return '{:.3f}'.format(
+        round(1 + points / (1000 * float(recipe['volume'])), 3)
+    )
+
+
+def recipe_fg(recipe):
+    """Returns a recipe's final gravity"""
+    if 'yeast' not in recipe:
+        return 0.0
+    og = float(recipe_og(recipe))
+    og_delta = 0.0
+    # Adjust original gravity by removing nonfermentables (i.e., Lactose)
+    for fermentable in recipe['fermentables']:
+        if fermentable['type'] == 'Non-fermentable':
+            og_delta += (
+                float(fermentable['amount']) * float(fermentable['ppg']) /
+                (1000 * float(recipe['volume']))
+            )
+    attenuation = (
+        (
+            float(recipe['yeast']['low_attenuation']) +
+            float(recipe['yeast']['high_attenuation'])
+        ) / 200
+    )
+    print(og - 1 - og_delta)
+    print(attenuation)
+    print(og_delta)
+    return '{:.3f}'.format(
+        round(1 + (og - 1 - og_delta)*(1 - attenuation) + og_delta, 3)
+    )
+
+
+
+def create_filters(app):
+    app.add_template_filter(recipe_og)
+    app.add_template_filter(recipe_fg)

src/humulus/templates/recipes/info.html

@@ -32,6 +32,10 @@
       <dd>{{ recipe.efficiency|int }}%</dd>
       <dt>Batch Volume</dt>
       <dd>{{ recipe.volume|float|round(1) }} gal.</dd>
+      <dt>OG</dt>
+      <dd>{{ recipe|recipe_og }}</dd>
+      <dt>FG</dt>
+      <dd>{{ recipe|recipe_fg }}</dd>
     </dl>
   </div>
   <div class="col">

tests/conftest.py

@@ -152,3 +152,68 @@ class AuthActions(object):
 @pytest.fixture
 def auth(client):
     return AuthActions(client)
+
+
+@pytest.fixture
+def sample_recipes():
+    """These sample recipes are useful for testing filters."""
+    return {
+        'blonde-ale': {
+            'efficiency': '68.00',
+            'fermentables': [
+                {
+                    'amount': '8.50',
+                    'color': '1.80',
+                    'name': 'Pale Malt, 2-row (Rahr) (US)',
+                    'ppg': '37.00',
+                    'type': 'Grain'
+                },
+                {
+                    'amount': '0.50',
+                    'color': '10.00',
+                    'name': 'Munich Malt 10L (Briess) (US)',
+                    'ppg': '35.00',
+                    'type': 'Grain'
+                }
+            ],
+            'hops': [
+                {
+                    'alpha': '9.30',
+                    'amount': '0.50',
+                    'duration': '30.00',
+                    'name': 'Cascade (US)',
+                    'use': 'Boil'
+                },
+                {
+                    'alpha': '9.30',
+                    'amount': '0.50',
+                    'duration': '15.00',
+                    'name': 'Cascade (US)',
+                    'use': 'Boil'
+                },
+                {
+                    'alpha': '9.30',
+                    'amount': '1.00',
+                    'duration': '5.00',
+                    'name': 'Cascade (US)',
+                    'use': 'Boil'
+                }
+            ],
+            'name': 'Blonde Ale Base',
+            'notes': "This is a base recipe. It's okay on its own, but"
+                     'better with other things, like fruits.',
+            'volume': '5.50',
+            'yeast': {
+                'abv_tolerance': '15.00',
+                'code': 'WLP090',
+                'flocculation': 'High',
+                'high_attenuation': '83.00',
+                'lab': 'White Labs',
+                'low_attenuation': '76.00',
+                'max_temperature': '68.00',
+                'min_temperature': '65.00',
+                'name': 'San Diego Super Yeast',
+                'type': 'Liquid'
+            }
+        }
+    }

tests/test_filters.py

@@ -0,0 +1,24 @@
+# Copyright 2019 Mike Shoup
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from humulus.filters import *
+
+
+def test_recipe_og(sample_recipes):
+    assert recipe_og(sample_recipes['blonde-ale']) == '1.041'
+
+
+def test_recipe_fg(sample_recipes):
+    assert recipe_fg(sample_recipes['blonde-ale']) == '1.008'