add a missing desired_matches function to mimeparse (was removed upstream, but still used in paste)

1 files changed, 34 insertions, 11 deletions

diff --git a/paste/util/mimeparse.py b/paste/util/mimeparse.py
index 0fd91e7..a8793b2 100644
--- a/paste/util/mimeparse.py
+++ b/paste/util/mimeparse.py
@@ -1,7 +1,7 @@
 """MIME-Type Parser
 
 This module provides basic functions for handling mime-types. It can handle
-matching mime-types against a list of media-ranges. See section 14.1 of 
+matching mime-types against a list of media-ranges. See section 14.1 of
 the HTTP specification [RFC 2616] for a complete explanation.
 
    http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.1
@@ -11,7 +11,7 @@ Contents:
     - parse_media_range(): Media-ranges are mime-types with wild-cards and a 'q' quality parameter.
     - quality():           Determines the quality ('q') of a mime-type when compared against a list of media-ranges.
     - quality_parsed():    Just like quality() except the second parameter must be pre-parsed.
-    - best_match():        Choose the mime-type with the highest quality ('q') from a list of candidates. 
+    - best_match():        Choose the mime-type with the highest quality ('q') from a list of candidates.
 """
 
 __version__ = "0.1.2"
@@ -47,7 +47,7 @@ def parse_media_range(range):
 
        ('application', '*', {'q', '0.5'})
 
-       In addition this function also guarantees that there 
+       In addition this function also guarantees that there
        is a value for 'q' in the params dictionary, filling it
        in with a proper default if necessary.
        """
@@ -59,14 +59,14 @@ def parse_media_range(range):
     return (type, subtype, params)
 
 def fitness_and_quality_parsed(mime_type, parsed_ranges):
-    """Find the best match for a given mime-type against 
-       a list of media_ranges that have already been 
+    """Find the best match for a given mime-type against
+       a list of media_ranges that have already been
        parsed by parse_media_range(). Returns a tuple of
        the fitness value and the value of the 'q' quality
        parameter of the best match, or (-1, 0) if no match
        was found. Just as for quality_parsed(), 'parsed_ranges'
        must be a list of parsed media ranges. """
-    best_fitness = -1 
+    best_fitness = -1
     best_fit_q = 0
     (target_type, target_subtype, target_params) =\
             parse_media_range(mime_type)
@@ -82,7 +82,7 @@ def fitness_and_quality_parsed(mime_type, parsed_ranges):
             if fitness > best_fitness:
                 best_fitness = fitness
                 best_fit_q = params['q']
-            
+
     return best_fitness, float(best_fit_q)
 
 def quality_parsed(mime_type, parsed_ranges):
@@ -101,18 +101,18 @@ def quality(mime_type, ranges):
 
     >>> quality('text/html','text/*;q=0.3, text/html;q=0.7, text/html;level=1, text/html;level=2;q=0.4, */*;q=0.5')
     0.7
-    
-    """ 
+
+    """
     parsed_ranges = [parse_media_range(r) for r in ranges.split(",")]
     return quality_parsed(mime_type, parsed_ranges)
 
 def best_match(supported, header):
     """Takes a list of supported mime-types and finds the best
     match for all the media-ranges listed in header. The value of
-    header must be a string that conforms to the format of the 
+    header must be a string that conforms to the format of the
     HTTP Accept: header. The value of 'supported' is a list of
     mime-types.
-    
+
     >>> best_match(['application/xbel+xml', 'text/xml'], 'text/*;q=0.5,*/*; q=0.1')
     'text/xml'
     """
@@ -121,3 +121,26 @@ def best_match(supported, header):
             for mime_type in supported]
     weighted_matches.sort()
     return weighted_matches[-1][0][1] and weighted_matches[-1][1] or ''
+
+def desired_matches(desired, header):
+    """Takes a list of desired mime-types in the order the server prefers to
+    send them regardless of the browsers preference.
+
+    Browsers (such as Firefox) technically want XML over HTML depending on how
+    one reads the specification. This function is provided for a server to
+    declare a set of desired mime-types it supports, and returns a subset of
+    the desired list in the same order should each one be Accepted by the
+    browser.
+
+    >>> sorted_match(['text/html', 'application/xml'], \
+    ...     'text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png')
+    ['text/html', 'application/xml']
+    >>> sorted_match(['text/html', 'application/xml'], 'application/xml,application/json')
+    ['application/xml']
+    """
+    matches = []
+    parsed_ranges = [parse_media_range(r) for r in header.split(",")]
+    for mimetype in desired:
+        if quality_parsed(mimetype, parsed_ranges):
+            matches.append(mimetype)
+    return matches