A technical track talk given by Episerver EMVP's (Me + Khurram Khan) about WebHooks at Episerver Ascend London 2015 (27th October)

1. EMVP Session
Mark Everard (@ev2000)
Khurram Khan
27th October 2015

2. Exposing /retrieving content via
publisher /subscriber
integrations using EPiServer

3. …Because I want to prove to
my boss that I’m actually
presenting today… Could any
Instagram users please post a
photo of the talk with the hashtag
#ascend15 thanks 

4. ASP.NET
SQL
EPiServer CMS /
Commerce
HTML / Pages
RSS / ATOM
Web-services (SOAP /
REST)
Custom implementation
ServiceAPI
FTP / CSV
Triggers / Mirroring
How can expose my content?
Websites
Mobile
Search
PIM
DAM
Translation
Backup
Reporting
DR
In-process or batch

5. ServiceAPI
Service Layer available to allow update and retrieval of
information from EPiServer (Commerce + CMS)
• EPiServer implementation of ASP.NET WebAPI
• Primary function to enable Commerce integrations (Catalog and
Media)
- Catalog
- Media
- CMS (bulk upload of .episerverdata files)
http://world.episerver.com/documentation/items/episerver-service-api

6. Publish / Subscribe
A messaging pattern allowing a system to publish a message to
all interested receivers.
• Loose coupling (publishers know nothing about subscribers)
• Scalable (though publisher accepts load)
• Flexibility (agree to one contract)
Loose coupling means that message delivery
guarantees are more difficult though can be achieved,
perhaps via an intermediary message broker or a convention.
Publisher
Subscribe
r
Subscribe
r
Subscribe
r

7. RSS / ATOM Feeds
RSS / ATOM is a web scale pub-sub implementation.
A system subscribes to a feed to which the publisher adds updates /
messages. Requires a polling approach from a subscriber.
Coincidentally, there’s a new version of Chief2moro.SyndicationFeeds
• Allows editors to create flexible feeds from EPiServer content
• Filter by ContentType – new feature
• Filter by Category – new feature
• Further developer extension points (filtering and item summary)
• Available as a Nuget package for CMS 9
https://github.com/markeverard/Chief2moro.SyndicationFeeds

8. WebHooks
“User defined HTTP callbacks”
Simple subscriber / publisher
notification system for web based
clients.
Notification delivery rather than
polling
Available on many services
already – social, cloud, payments
etc

9. …Captain Hook on the screen.
How AMAZING! I really should post
that to my Instagram with the
hashtag #ascend15 

10. WebHooks
A subscriber sends a payload to subscribe
to a particular notification. There is often
basic authentication involved (app secrets
and Id’s)
After a event the publisher looks at all
relevant subscriptions and delivers
message to all subscribers.
Messages are often lightweight containing
notification of events rather than
themselves detail about the events.
Publisher
Subscribe
r
Subscribe
r
Subscribe
r
POST
I want to
subscribe
Subscription
store
Publisher
Subscription
store
Event
Notifications
POST

11. ASP.NET WebHooks
Lightweight framework gives you a pattern for building:
• Handling subscriptions from interested subscribers
• Sending subscriptions to publishers
• Sending published messages to subscribers
• Handling publisher messages from subscribed services (via Receivers)
https://github.com/aspnet/WebHooks/
• Subscriptions gives you a way to manage and store subscriptions, and
to make call-backs to all subscribed urls (hooks) at the right time.
• Receivers accept a defined HTTP payload from an external service
(HTTP POST)

12. ASP.NET WebHooks
Along with a basic framework for sending and handling
subscriptions and publishing and receiving notifications, the
ASP.NET implementation also provides some fleshed out
integrations for the following services. Less work for you!
• Azure Alerts, Dropbox, GitHub, Kudu, Instagram, MailChimp,
PayPal, Pusher, Salesforce, Slack, Stripe, Trello, and
WordPress

13. What abour Signalr?
Signalr is also a messaging technology that also allows for non-polling
communications between systems.
So what’s the difference?
• Signalr is for client to server communication, for example between
browsers and webservers, allowing efficient and real-time data
exchange
• WebHooks are for server to server communication relying on HTTP
requests to Urls, for example GitHub notifying Azure to deploy a
branch after a commit.

14. EPiServer WebHooks
What would an EPiServer implementation / usage of WebHooks
look like?
• Publish content events to subscribers (system to system
integration)
• Publish Form data inputs to external systems
• Publish / Subscribe to Catalog events and changes from
integrated commerce systems (Stock control and pricing)
• Subscribe to events from external systems (Payments)
• Subscribe to external content events – Instagram anyone?

15. Code – Example Inventory /
Pricing WebHooks in Commerce

16. “Asacontenteditor,Iwantimagesthatare
uploadedonasocialchannel(Instagram)
andtaggedwith‘ascend15’tobeavailablein
mycontentmanagement systemsoIcan
usethemonmyawesomewebsite”
Have you posted your picture tagged with
‘ascend15’ yet? Live demo coming soon

17. Code – Instagram WebHooks
with EPiServer CMS

18. Thanks