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643dca0071
This means we can cache them forever, and only invalidate the cache when the image changes.
49 lines
1.4 KiB
Python
49 lines
1.4 KiB
Python
import hashlib
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class AssetFingerprinter(object):
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"""
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Get a unique hash for an asset file, so that it doesn't stay cached
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when it changes
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Usage:
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in the application
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template_data.asset_fingerprinter = AssetFingerprinter()
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where template data is how you pass variables to every template.
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in template.html:
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{{ asset_fingerprinter.get_url('stylesheets/application.css') }}
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* 'app/static' is assumed to be the root for all asset files
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"""
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def __init__(self, asset_root='/static/', filesystem_path='app/static/'):
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self._cache = {}
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self._asset_root = asset_root
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self._filesystem_path = filesystem_path
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def get_url(self, asset_path):
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if asset_path not in self._cache:
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self._cache[asset_path] = (
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self._asset_root +
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asset_path +
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'?' +
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self.get_asset_fingerprint(self._filesystem_path + asset_path)
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)
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return self._cache[asset_path]
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def get_asset_fingerprint(self, asset_file_path):
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return hashlib.md5(
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self.get_asset_file_contents(asset_file_path)
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).hexdigest()
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def get_asset_file_contents(self, asset_file_path):
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with open(asset_file_path, 'rb') as asset_file:
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contents = asset_file.read()
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return contents
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asset_fingerprinter = AssetFingerprinter()
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