Add redcap_version attribute to Project

On Project initialization PyCap will attempt to determine the REDCap version that the project is associated with. If it cannot it will warn the user that version information is unavailable. This implements [python-semanticversion](https://github.com/rbarrois/python-semanticversion) which allows for easy version comparison and assumes that REDCap will stick with its versioning conventions to date. If for whatever reason they differ, PyCap will simply return the string representation of the version from REDCap's API. Fixes #43.

redcap/project.py

@@ -6,9 +6,10 @@
 __copyright__ = '2014, Vanderbilt University'
 
 import json
+import warnings
 
 from .request import RCRequest, RedcapError, RequestException
-
+import semantic_version
 
 class Project(object):
     """Main class for interacting with REDCap projects"""
@@ -35,6 +36,10 @@ def __init__(self, url, token, name='', verify_ssl=True):
             self.metadata = self.__md()
         except RequestException:
             raise RedcapError("Exporting metadata failed. Check your URL and token.")
+        try:
+            self.redcap_version = self.__rcv()
+        except:
+            raise RedcapError("Determination of REDCap version failed")
         self.field_names = self.filter_metadata('field_name')
         # we'll use the first field as the default id for each row
         self.def_field = self.field_names[0]
@@ -69,6 +74,17 @@ def __basepl(self, content, rec_type='flat', format='json'):
             d['type'] = rec_type
         return d
 
+    def __rcv(self):
+        p_l = self.__basepl('version')
+        rcv = self._call_api(p_l, 'version')[0]
+        if 'error' in rcv:
+            warnings.warn('Version information not available for this REDCap instance')
+            return ''
+        if semantic_version.validate(rcv):
+            return semantic_version.Version(rcv)
+        else:
+            return rcv
+
     def is_longitudinal(self):
         """
         Returns

redcap/request.py

@@ -84,7 +84,9 @@ def validate(self):
             'exp_fem': (['format'], 'formEventMapping',
                 'Exporting form-event mappings but content != formEventMapping'),
             'exp_user': (['format'], 'user',
-                'Exporting users but content is not user')
+		'Exporting users but content is not user'),
+	    'version': (['format'], 'version',
+		'Requesting version but content != version')
         }
         extra, req_content, err_msg = valid_data[self.type]
         required.extend(extra)
@@ -127,6 +129,8 @@ def get_content(self, r):
         if self.type == 'exp_file':
             # don't use the decoded r.text
             return r.content
+	elif self.type == 'version':
+	    return r.content
         else:
             if self.fmt == 'json':
                 content = {}

requirements.txt

@@ -1,5 +1,6 @@
 Sphinx==1.2.1
 nose==1.2.1
 numpydoc==0.4
+semantic-version==2.3.1
 requests>=1.1.0
 wheel==0.22.0

setup.py

@@ -20,7 +20,10 @@ def get_version():
         exec(f.read())
         return VERSION
 
-required = ['requests>=1.0.0']
+required = [
+    'requests>=1.0.0',
+    'semantic-version==2.3.1'
+]
 
 if __name__ == '__main__':
     if os.path.exists('MANIFEST'):

test/test_project.py

@@ -2,6 +2,7 @@
 
 import unittest
 from redcap import Project, RedcapError
+import semantic_version
 
 skip_pd = False
 try:
@@ -292,3 +293,7 @@ def import_factory(date_string):
         import_mdy = import_factory('12/31/2000')
         response = self.reg_proj.import_records(import_mdy, date_format='MDY')
         self.assertEqual(response['count'], 1)
+
+    def test_get_version(self):
+	"""Testing retrieval of REDCap version associated with Project"""
+	self.assertTrue(isinstance(semantic_version.Version('1.0.0'), type(self.long_proj.redcap_version)))