Add AUTO_RELOAD option to WebpackLoader

README.md

@@ -86,6 +86,7 @@ module.exports = {
 WEBPACK_LOADER = {
  'DEFAULT': {
  'CACHE': not DEBUG,
+ 'AUTO_RELOAD': False,
  'BUNDLE_DIR_NAME': 'webpack_bundles/', # must end with slash
  'STATS_FILE': os.path.join(BASE_DIR, 'webpack-stats.json'),
  'POLL_INTERVAL': 0.1,
@@ -101,11 +102,15 @@ WEBPACK_LOADER = {
 ```python
 WEBPACK_LOADER = {
  'DEFAULT': {
- 'CACHE': not DEBUG
+ 'CACHE': not DEBUG,
+ 'AUTO_RELOAD': True
  }
 }
 ```
-When `CACHE` is set to True, webpack-loader will read the stats file only once and cache the result. This means web workers need to be restarted in order to pick up any changes made to the stats files.
+When `CACHE` and `AUTO_RELOAD` are set to True, webpack-loader will read the stats file only once and cache the result. Wepback will watch the stats file for any changes (based on the modification time of the file). If the file is changed webpack-loader will automatically pick up any changes made to the stats files but otherwise use the cache.
+
+When `AUTO_RELOAD` is set to False, webpack-loader will read the stats file only once and cache the result. This means web workers need to be restarted in order to pick up any changes made to the stats files.
+
 
 <br>
 

tests/app/tests/test_webpack.py

@@ -16,8 +16,13 @@
  WebpackLoaderTimeoutError,
  WebpackBundleLookupError
 )
+from webpack_loader.loader import WebpackLoader
 from webpack_loader.utils import get_loader
 
+try:
+ import unittest.mock as mock
+except ImportError:
+ import mock
 
 BUNDLE_PATH = os.path.join(settings.BASE_DIR, 'assets/bundles/')
 DEFAULT_CONFIG = 'DEFAULT'
@@ -246,3 +251,95 @@ def test_request_blocking(self):
  result.rendered_content
  elapsed = time.time() - then
  self.assertTrue(elapsed < wait_for)
+
+ def test_no_shared_state_between_loader_instances(self):
+ self.compile_bundles('webpack.config.simple.js')
+
+ loader = WebpackLoader()
+ loader.config['CACHE'] = True
+
+ try:
+ assets = loader.get_assets()
+
+ self.assertIn('chunks', assets)
+
+ # A new instance of the WebpackLoader should now start with an empty
+ # cache
+ with mock.patch(
+ 'webpack_loader.loader.open', mock.mock_open(read_data='{}')):
+ loader = WebpackLoader()
+ loader.config['CACHE'] = True
+ assets = loader.get_assets()
+ self.assertNotIn('chunks', assets)
+ finally:
+ loader.config['CACHE'] = False
+
+ def test_caching_disabled(self):
+ self.compile_bundles('webpack.config.simple.js')
+
+ # Don't use get_loader to prevent sharing state with other tests
+ loader = WebpackLoader()
+ assets = loader.get_assets()
+
+ self.assertIn('chunks', assets)
+
+ # Caching is disabled so another call to get_assets should trigger
+ # a reload of the bundle, mock open to change the contents
+ with mock.patch(
+ 'webpack_loader.loader.open', mock.mock_open(read_data='{}')):
+ assets = loader.get_assets()
+ self.assertEqual(assets, {})
+
+ def test_caching_enabled(self):
+ self.compile_bundles('webpack.config.simple.js')
+
+ # Don't use get_loader to prevent sharing state with other tests
+ loader = WebpackLoader()
+ loader.config['CACHE'] = True
+ try:
+ assets = loader.get_assets()
+
+ self.assertIn('chunks', assets)
+
+ # Caching is enabled so another call to get_assets should not trigger
+ # a reload of the bundle
+ with mock.patch(
+ 'webpack_loader.loader.open', mock.mock_open(read_data='{}')):
+ assets = loader.get_assets()
+ self.assertIn('chunks', assets)
+ finally:
+ loader.config['CACHE'] = False
+
+ def test_caching_enabled_with_auto_reload(self):
+ self.compile_bundles('webpack.config.simple.js')
+
+ # Don't use get_loader to prevent sharing state with other tests
+ loader = WebpackLoader()
+ loader.config['CACHE'] = True
+ loader.config['AUTO_RELOAD'] = True
+
+ try:
+ assets = loader.get_assets()
+
+ self.assertIn('chunks', assets)
+
+ # If file has same mtime, hit cache
+ with mock.patch(
+ 'webpack_loader.loader.open', mock.mock_open(read_data='{}')):
+ assets = loader.get_assets()
+ self.assertIn('chunks', assets)
+
+ assets = loader.get_assets()
+
+ self.assertIn('chunks', assets)
+
+ # When mtime changes, auto reload
+ os.utime(loader.config['STATS_FILE'], None)
+
+ with mock.patch(
+ 'webpack_loader.loader.open', mock.mock_open(read_data='{}')):
+ assets = loader.get_assets()
+ self.assertEqual(assets, {})
+ finally:
+ loader.config['CACHE'] = False
+ loader.config['AUTO_RELOAD'] = False

tests/tox.ini

@@ -26,5 +26,6 @@ deps =
  django19: django>=1.9.0,<1.10.0
  django110: django>=1.10.0,<1.11.0
  django111: django>=1.11.0,<2.0
+ {py26,py27}: mock
 commands =
  coverage run --source=webpack_loader manage.py test {posargs}

webpack_loader/config.py

@@ -9,6 +9,7 @@
 DEFAULT_CONFIG = {
  'DEFAULT': {
  'CACHE': not settings.DEBUG,
+ 'AUTO_RELOAD': False,
  'BUNDLE_DIR_NAME': 'webpack_bundles/',
  'STATS_FILE': 'webpack-stats.json',
  # FIXME: Explore usage of fsnotify

webpack_loader/loader.py

@@ -1,4 +1,5 @@
 import json
+import os
 import time
 from io import open
 
@@ -15,9 +16,10 @@
 
 
 class WebpackLoader(object):
- _assets = {}
 
  def __init__(self, name='DEFAULT'):
+ self._assets = {}
+ self._mtimes = {}
  self.name = name
  self.config = load_config(self.name)
 
@@ -31,10 +33,27 @@ def _load_assets(self):
  'the file and the path is correct?'.format(
  self.config['STATS_FILE']))
 
+ def _reload_assets_on_change(self):
+ # If no entry yet in _mtimes then this is the initial load
+ # set mtime and leave cache untouched
+ if self.name not in self._mtimes:
+ self._mtimes[self.name] = os.path.getmtime(
+ self.config['STATS_FILE'])
+ return
+
+ mtime = os.path.getmtime(self.config['STATS_FILE'])
+ if self._mtimes[self.name] < mtime:
+ self._assets[self.name] = self._load_assets()
+ self._mtimes[self.name] = mtime
+
  def get_assets(self):
  if self.config['CACHE']:
  if self.name not in self._assets:
  self._assets[self.name] = self._load_assets()
+
+ if self.config['AUTO_RELOAD']:
+ self._reload_assets_on_change()
+
  return self._assets[self.name]
  return self._load_assets()