From: Leandro Lucarella <llucax@gmail.com>
Date: Mon, 30 Aug 2010 23:14:32 +0000 (-0300)
Subject: Allow custom sorting when displaying several articles
X-Git-Url: https://git.llucax.com/software/blitiri.git/commitdiff_plain/2635e6fa99f5b3e693262307437fe5d71c78fb38?ds=sidebyside

Allow custom sorting when displaying several articles

A new form variable is accepted, "sort", to allow custom sorting when
several articles are rendered (default view, atom feed or list view).

The sort variable uses a very simple sort specification format:

[+-]?<field>?

Where "-" means reverse order, while "+" is regular, ascending, order.
Field specifies what article field will be used when sorting; title,
author, created, updated and uuid are accepted.

Both values are optional, and when one is omitted, a default will be used
according to the type of view being rendered.

Note: since "+" is used to encode " " in URLs, " " is accepted as an alias
for "+" to make easier to write URLs with sort specification manually.
---

diff --git a/blitiri.cgi b/blitiri.cgi
index 7816599..d709f30 100755
--- a/blitiri.cgi
+++ b/blitiri.cgi
@@ -869,20 +869,6 @@ class Article (object):
 			self.load()
 		return self._comments
 
-	def __cmp__(self, other):
-		if self.path == other.path:
-			return 0
-		if not self.created:
-			return 1
-		if not other.created:
-			return -1
-		if self.created < other.created:
-			return -1
-		return 1
-
-	def title_cmp(self, other):
-		return cmp(self.title, other.title)
-
 
 	def add_comment(self, author, raw_content, link = ''):
 		c = Comment(self, len(self.comments))
@@ -1154,6 +1140,37 @@ def render_style():
 	print 'Content-type: text/css\r\n\r\n',
 	print default_css
 
+# Get a dictionary with sort() arguments (key and reverse) by parsing the sort
+# specification format:
+# [+-]?<key>?
+# Where "-" is used to specify reverse order, while "+" is regular, ascending,
+# order (reverse = False). The key value is an Article's attribute name (title,
+# author, created, updated and uuid are accepted), and will be used as key for
+# sorting. If a value is omitted, that value is taken from the default, which
+# should be provided using the same format specification, with the difference
+# that all values must be provided for the default.
+def get_sort_args(sort_str, default):
+	def parse(s):
+		d = dict()
+		if not s:
+			return d
+		key = None
+		if len(s) > 0:
+			# accept ' ' as an alias of '+' since '+' is translated
+			# to ' ' in URLs
+			if s[0] in ('+', ' ', '-'):
+				key = s[1:]
+				d['reverse'] = (s[0] == '-')
+			else:
+				key = s
+		if key in ('title', 'author', 'created', 'updated', 'uuid'):
+			d['key'] = lambda a: getattr(a, key)
+		return d
+	args = parse(default)
+	assert args['key'] is not None and args['reverse'] is not None
+	args.update(parse(sort_str))
+	return args
+
 def handle_cgi():
 	import cgitb; cgitb.enable()
 
@@ -1162,6 +1179,7 @@ def handle_cgi():
 	month = int(form.getfirst("month", 0))
 	day = int(form.getfirst("day", 0))
 	tags = set(form.getlist("tag"))
+	sort_str = form.getfirst("sort", None)
 	uuid = None
 	atom = False
 	style = False
@@ -1220,7 +1238,7 @@ def handle_cgi():
 	db = ArticleDB(os.path.join(data_path, 'db'))
 	if atom:
 		articles = db.get_articles(tags = tags)
-		articles.sort(reverse = True)
+		articles.sort(**get_sort_args(sort_str, '-created'))
 		render_atom(articles[:index_articles])
 	elif style:
 		render_style()
@@ -1232,7 +1250,7 @@ def handle_cgi():
 		render_html( [article], db, year, enable_comments )
 	elif artlist:
 		articles = db.get_articles()
-		articles.sort(cmp = Article.title_cmp)
+		articles.sort(**get_sort_args(sort_str, '+title'))
 		render_artlist(articles, db)
 	elif comment and enable_comments:
 		form_data = CommentFormData(author.strip().replace('\n', ' '),
@@ -1282,7 +1300,7 @@ def handle_cgi():
 				form_data )
 	else:
 		articles = db.get_articles(year, month, day, tags)
-		articles.sort(reverse = True)
+		articles.sort(**get_sort_args(sort_str, '-created'))
 		if not year and not month and not day and not tags:
 			articles = articles[:index_articles]
 		render_html(articles, db, year)