From c425d5533116cc5a623ee2c614a68bf8e13513f6 Mon Sep 17 00:00:00 2001
From: Ethan Dalool <git@voussoir.net>
Date: Wed, 9 Sep 2020 13:23:16 -0700
Subject: [PATCH] Use decorators in jinja_filters to automatically register
 them.

---
 frontends/etiquette_flask/backend/common.py   |  9 +------
 .../etiquette_flask/backend/jinja_filters.py  | 26 +++++++++++++++++++
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/frontends/etiquette_flask/backend/common.py b/frontends/etiquette_flask/backend/common.py
index 2fa24d4..0c6befc 100644
--- a/frontends/etiquette_flask/backend/common.py
+++ b/frontends/etiquette_flask/backend/common.py
@@ -32,14 +32,7 @@ site.config.update(
 site.jinja_env.add_extension('jinja2.ext.do')
 site.jinja_env.trim_blocks = True
 site.jinja_env.lstrip_blocks = True
-site.jinja_env.filters['bytestring'] = jinja_filters.bytestring
-site.jinja_env.filters['comma_join'] = jinja_filters.comma_join
-site.jinja_env.filters['file_link'] = jinja_filters.file_link
-site.jinja_env.filters['sort_tags'] = jinja_filters.sort_tags
-site.jinja_env.filters['timestamp_to_8601'] = jinja_filters.timestamp_to_8601
-site.jinja_env.filters['timestamp_to_naturaldate'] = jinja_filters.timestamp_to_naturaldate
-site.jinja_env.filters['users_to_usernames'] = jinja_filters.users_to_usernames
-site.jinja_env.globals['make_attributes'] = jinja_filters.make_attributes
+jinja_filters.register_all(site)
 site.debug = True
 
 P = etiquette.photodb.PhotoDB()
diff --git a/frontends/etiquette_flask/backend/jinja_filters.py b/frontends/etiquette_flask/backend/jinja_filters.py
index c68e875..e2f035d 100644
--- a/frontends/etiquette_flask/backend/jinja_filters.py
+++ b/frontends/etiquette_flask/backend/jinja_filters.py
@@ -3,24 +3,45 @@ import jinja2.filters
 
 import voussoirkit.bytestring
 
+filter_functions = []
+global_functions = []
 
+def filter_function(function):
+    filter_functions.append(function)
+    return function
+
+def global_function(function):
+    global_functions.append(function)
+    return function
+
+def register_all(site):
+    for function in filter_functions:
+        site.jinja_env.filters[function.__name__] = function
+
+    for function in global_functions:
+        site.jinja_env.globals[function.__name__] = function
+
+@filter_function
 def bytestring(x):
     try:
         return voussoirkit.bytestring.bytestring(x)
     except Exception as e:
         return '??? b'
 
+@filter_function
 def comma_join(l):
     if not l:
         return ''
     return ', '.join(l)
 
+@filter_function
 def file_link(photo, short=False):
     if short:
         return f'/file/{photo.id}{photo.dot_extension}'
     basename = jinja2.filters.do_urlencode(photo.basename)
     return f'/file/{photo.id}/{basename}'
 
+@global_function
 def make_attributes(*booleans, **keyvalues):
     keyvalues = {key: value for (key, value) in keyvalues.items() if value is not None}
     attributes = [f'{key}="{jinja2.filters.escape(value)}"' for (key, value) in keyvalues.items()]
@@ -28,20 +49,25 @@ def make_attributes(*booleans, **keyvalues):
     attributes = ' '.join(attributes)
     return attributes
 
+@filter_function
 def sort_tags(tags):
     tags = sorted(tags, key=lambda x: x.name)
     return tags
 
+@filter_function
 def timestamp_to_8601(timestamp):
     return datetime.datetime.utcfromtimestamp(timestamp).isoformat(' ') + ' UTC'
 
+@filter_function
 def timestamp_to_string(timestamp, format):
     date = datetime.datetime.utcfromtimestamp(timestamp)
     return date.strftime(format)
 
+@filter_function
 def timestamp_to_naturaldate(timestamp):
     return timestamp_to_string(timestamp, '%B %d, %Y')
 
+@filter_function
 def users_to_usernames(users):
     if not users:
         return []