Strip non-numeric characters from phone number

Allows user to type in phone number in whichever
format they prefer.

openedx/core/djangoapps/user_api/accounts/serializers.py

@@ -5,6 +5,7 @@ Django REST Framework serializers for the User API Accounts sub-application
 
 import json
 import logging
+import re
 
 from django.conf import settings
 from django.contrib.auth.models import User
@@ -37,6 +38,15 @@ PROFILE_IMAGE_KEY_PREFIX = 'image_url'
 LOGGER = logging.getLogger(__name__)
 
 
+class PhoneNumberSerializer(serializers.BaseSerializer):
+    """
+    Class to serialize phone number into a digit only representation
+    """
+    def to_internal_value(self, data):
+        """Remove all non numeric characters in phone number"""
+        return re.sub("[^0-9]", "", data) or None
+
+
 class LanguageProficiencySerializer(serializers.ModelSerializer):
     """
     Class that serializes the LanguageProficiency model for account
@@ -223,6 +233,7 @@ class AccountLegacyProfileSerializer(serializers.HyperlinkedModelSerializer, Rea
     requires_parental_consent = serializers.SerializerMethodField()
     language_proficiencies = LanguageProficiencySerializer(many=True, required=False)
     social_links = SocialLinkSerializer(many=True, required=False)
+    phone_number = PhoneNumberSerializer(required=False)
 
     class Meta(object):
         model = UserProfile