json support: better import logic (#831)

1 files changed, 19 insertions, 13 deletions

diff --git a/cherrypy/lib/jsontools.py b/cherrypy/lib/jsontools.py
index 17cd8a1e..e71874a8 100644
--- a/cherrypy/lib/jsontools.py
+++ b/cherrypy/lib/jsontools.py
@@ -1,13 +1,24 @@
 import cherrypy
 
-json_codecs = {}
+try:
+    # Python 2.6: simplejson is part of the standard library
+    import json
+except ImportError:
+    try:
+        import simplejson as json
+    except ImportError:
+        json = None
+
+if json is None:
+    def json_decode(s):
+        raise ValueError('No JSON library is available')
+    def json_encode(s):
+        raise ValueError('No JSON library is available')
+else:
+    json_decode = json.JSONDecoder().decode
+    json_encode = json.JSONEncoder().iterencode
 
 def json_in(*args, **kwargs):
-    if 'decoder' not in json_codecs:
-        # we don't want to import simplejson until we're sure we need it
-        from simplejson import JSONDecoder
-        json_codecs['decoder'] = JSONDecoder()
-
     request = cherrypy.request
     _h = request.headers
     if ('Content-Type' not in _h
@@ -18,18 +29,13 @@ def json_in(*args, **kwargs):
     body = request.body.read(length)
 
     try:
-        json = json_codecs['decoder'].decode(body)
+        json = json_decode(body)
     except ValueError:
         raise cherrypy.HTTPError(400, 'Invalid JSON document')
 
     request.json = json
 
 def json_out(*args, **kwargs):
-    if 'encoder' not in json_codecs:
-        # we don't want to import simplejson until we're sure we need it
-        from simplejson import JSONEncoder
-        json_codecs['encoder'] = JSONEncoder()
-
     request = cherrypy.request
     response = cherrypy.response
 
@@ -37,5 +43,5 @@ def json_out(*args, **kwargs):
     def json_handler(*args, **kwargs):
         response.headers['Content-Type'] = 'application/json'
         value = real_handler(*args, **kwargs)
-        return json_codecs['encoder'].iterencode(value)
+        return json_encode(value)
     request.handler = json_handler