Call Decoder.string(), if that is implemented

docs/decoder.rst

@@ -106,3 +106,40 @@
          >>> od = OrderedDecoder()
          >>> type(od('{"foo": "bar"}'))
          <class 'collections.OrderedDict'>
+
+   .. method:: string(s)
+
+      :param s: a ``str`` instance
+      :returns: a new value
+
+      This method, when implemented, is called whenever a *JSON string* has
+      been completely parsed, and can be used to replace it with an arbitrary
+      different value:
+
+      .. doctest::
+
+         >>> class SwapStringCase(Decoder):
+         ...   def string(self, s):
+         ...     return s.swapcase()
+         ...
+         >>> ssc = SwapStringCase()
+         >>> ssc('"Hello World!"')
+         'hELLO wORLD!'
+
+      Note that it is called **after** the recognition of dates and UUIDs,
+      when `datetime_mode` and/or `uuid_mode` are specified:
+
+      .. doctest::
+
+         >>> class DDMMYYYY(Decoder):
+         ...   def string(self, s):
+         ...     if len(s) == 8 and s.isdigit():
+         ...       dd = int(s[:2])
+         ...       mm = int(s[2:4])
+         ...       yyyy = int(s[-4:])
+         ...       return (yyyy, mm, dd)
+         ...     return s
+         ...
+         >>> ddmmyyyy = DDMMYYYY(datetime_mode=DM_ISO8601)
+         >>> ddmmyyyy('["2017-08-21", "21082017"]')
+         [datetime.date(2017, 8, 21), (2017, 8, 21)]

rapidjson.cpp

@@ -40,6 +40,7 @@ static PyObject* start_object_name = NULL;
 static PyObject* end_object_name = NULL;
 static PyObject* default_name = NULL;
 static PyObject* end_array_name = NULL;
+static PyObject* string_name = NULL;
 
 static PyObject* minus_inf_string_value = NULL;
 static PyObject* nan_string_value = NULL;
@@ -157,6 +158,7 @@ struct PyHandler {
     PyObject* decoderStartObject;
     PyObject* decoderEndObject;
     PyObject* decoderEndArray;
+    PyObject* decoderString;
     PyObject* root;
     PyObject* objectHook;
     DatetimeMode datetimeMode;
@@ -168,6 +170,7 @@ struct PyHandler {
         : decoderStartObject(NULL),
           decoderEndObject(NULL),
           decoderEndArray(NULL),
+          decoderString(NULL),
           root(NULL),
           objectHook(hook),
           datetimeMode(dm),
@@ -189,13 +192,18 @@ struct PyHandler {
                 decoderEndArray = PyObject_GetAttr(decoder, end_array_name);
                 Py_INCREF(decoderEndArray);
             }
+            if (PyObject_HasAttr(decoder, string_name)) {
+                decoderString = PyObject_GetAttr(decoder, string_name);
+                Py_INCREF(decoderString);
+            }
         }
     }
 
     ~PyHandler() {
         Py_CLEAR(decoderStartObject);
         Py_CLEAR(decoderEndObject);
         Py_CLEAR(decoderEndArray);
+        Py_CLEAR(decoderString);
     }
 
     bool Handle(PyObject* value) {
@@ -912,6 +920,17 @@ struct PyHandler {
             return HandleUuid(str, length);
 
         value = PyUnicode_FromStringAndSize(str, length);
+        if (value == NULL)
+            return false;
+
+        if (decoderString != NULL) {
+            PyObject* replacement = PyObject_CallFunctionObjArgs(decoderString, value, NULL);
+            Py_DECREF(value);
+            if (replacement == NULL)
+                return false;
+            value = replacement;
+        }
+
         return Handle(value);
     }
 };
@@ -2707,6 +2726,10 @@ PyInit_rapidjson()
     if (end_array_name == NULL)
         goto error;
 
+    string_name = PyUnicode_InternFromString("string");
+    if (string_name == NULL)
+        goto error;
+
     PyObject* m;
 
     m = PyModule_Create(&module);
@@ -2772,6 +2795,7 @@ PyInit_rapidjson()
     Py_CLEAR(end_object_name);
     Py_CLEAR(default_name);
     Py_CLEAR(end_array_name);
+    Py_CLEAR(string_name);
 
     return NULL;
 }