Add basic Linkedin messaging provider

For now, this provider only supports basic publishing of entries as
post. It does not support any polling, and it does not support
collecting sponsor/speaker id's and highlighting them in notices. This
can be added later, but it can't be done properly without linkedin app
credentials that are not rate limited (the default), and you can't get
those credentials without already having an app.

As linkedin doesn't support the offline code flow for logins, this also
implements an oauth endpoint for incoming oauth flows for messaging
provider.

Finally, unlike the other messaging providers, linkedin actually expire
their oauth tokens - 2 months for the access token and 12 months for the
refresh token. To handle that, implement token refresh as part of the
validation flow, and simply flag that one as failed if the login doesn't
work.

1 files changed, 28 insertions, 0 deletions

diff --git a/postgresqleu/util/views.py b/postgresqleu/util/views.py
index 5d36d310..9ec82e0b 100644
--- a/postgresqleu/util/views.py
+++ b/postgresqleu/util/views.py
@@ -26,6 +26,34 @@ def markdown_preview(request):
 
 
 @csrf_exempt
+def oauth_return(request, providerid):
+    if 'code' not in request.GET:
+        raise Http404('Code missing')
+
+    provider = get_object_or_404(MessagingProvider, id=providerid)
+    impl = get_messaging(provider)
+    if hasattr(impl, 'oauth_return'):
+        err = impl.oauth_return(request)
+        if err:
+            return HttpResponse(err)
+        else:
+            if povider.series__id:
+                return HttpResponseRedirect('{}/events/admin/_series/{}/messaging/{}/'.format(
+                    settings.SITEBASE,
+                    provider.series_id,
+                    provider.id,
+                ))
+            else:
+                return HttpResponseRedirect('{}/events/admin/news/messagingproviders/{}/'.format(
+                    settings.SITEBASE,
+                    provider.id,
+                ))
+
+    else:
+        return HttpResponse('Unconfigured')
+
+
+@csrf_exempt
 def messaging_webhook(request, providerid, token):
     provider = get_object_or_404(MessagingProvider, id=providerid, config__webhook__token=token)
     impl = get_messaging(provider)