version-based mobile app upgrade

lms/djangoapps/mobile_api/mobile_platform.py

@@ -0,0 +1,69 @@
+"""
+Platform related Operations for Mobile APP
+"""
+import abc
+import re
+
+
+class MobilePlatform:
+    """
+    MobilePlatform class creates an instance of platform based on user agent and supports platform
+    related operations.
+    """
+    __metaclass__ = abc.ABCMeta
+    version = None
+
+    def __init__(self, version):
+        self.version = version
+
+    @classmethod
+    def get_user_app_platform(cls, user_agent, user_agent_regex):
+        """
+        Returns platform instance if user_agent matches with USER_AGENT_REGEX
+
+        Arguments:
+            user_agent (str): user-agent for mobile app making the request.
+            user_agent_regex (regex str): Regex for user-agent valid for any type pf mobile platform.
+
+        Returns:
+           An instance of class passed (which would be one of the supported mobile platform
+           classes i.e. PLATFORM_CLASSES) if user_agent matches regex of that class else returns None
+        """
+        match = re.search(user_agent_regex, user_agent)
+        if match:
+            return cls(match.group('version'))
+
+    @classmethod
+    def get_instance(cls, user_agent):
+        """
+        It creates an instance of one of the supported mobile platforms (i.e. iOS, Android) by regex comparison
+        of user-agent.
+
+        Parameters:
+            user_agent: user_agent of mobile app
+
+        Returns:
+            instance of one of the supported mobile platforms (i.e. iOS, Android)
+        """
+        for subclass in PLATFORM_CLASSES.values():
+            instance = subclass.get_user_app_platform(user_agent, subclass.USER_AGENT_REGEX)
+            if instance:
+                return instance
+
+
+class IOS(MobilePlatform):
+    """ iOS platform """
+    USER_AGENT_REGEX = (r'\((?P<version>[0-9]+.[0-9]+.[0-9]+(.[0-9a-zA-Z]*)?); OS Version [0-9.]+ '
+                        r'\(Build [0-9a-zA-Z]*\)\)')
+    NAME = "iOS"
+
+
+class Android(MobilePlatform):
+    """ Android platform """
+    USER_AGENT_REGEX = (r'Dalvik/[.0-9]+ \(Linux; U; Android [.0-9]+; (.*) Build/[0-9a-zA-Z]*\) '
+                        r'(.*)/(?P<version>[0-9]+.[0-9]+.[0-9]+(.[0-9a-zA-Z]*)?)')
+    NAME = "Android"
+
+
+# a list of all supported mobile platforms
+PLATFORM_CLASSES = {IOS.NAME: IOS, Android.NAME: Android}