Overview of the Elixir based Phoenix Framework highlighting what it makes it so productive, fast and different from the other web framework. Second part describse my experience using Phoenix as a contributor to some of the open source projects leaded by evercam.io http://evercam.io, an exciting new start-up based in Dublin that specialises in Apps and Developer tools to manage IP based cameras.

1. Manage PTZ Cameras with Phoenix
José C García-Sacristán
@jgsacristan

3. “Phoenix is a framework for building
HTML5 apps, API backends and
distributed systems to take on the
modern Web.”
“Written in Elixir, you get beautiful
syntax, productive tooling and a fast
runtime”

4. 2 million connections per server
400 million users, 30 engineers

6. Erlang
• Created in 1986
- Windows in 1985
- Linux in 1991
• Handles 50% of the worlds telecom traffic
• Reported 99.9999999% availability (nine
nines)

8. Elixir
Elixir is a functional, concurrent, general-
purpose programming language that runs on the
Erlang virtual machine (BEAM). Elixir builds on
top of Erlang to provide distributed, fault-
tolerant, soft real-time, non-stop applications
but also extends it to support metaprogramming
with macros and polymorphism via protocols.

9. Productivity in Phoenix
• Short term productivity
- Documentation / Guides / Generators
- Eliminates trivial choices
• Long term productivity
- Maintainability
- Introspection

10. Easy installation
• $mix local.hex
• $ mix archive.install
https://github.com/phoenixframework/phoen
ix/releases/download/v1.0.2/phoenix_new-
1.0.2.ez
• $mix phoenix.new my_app

11. Endpoints

12. Routers

13. Controllers

16. Generators
$ mix phoenix.gen.html
$ mix phoenix.gen.json
$ mix phoenix.gen.channel

17. Views & Templates
• Precompiled. Fast
• Views render templates.
• Views serve as a presentation layer
• Beyond HTML

18. Performance

19. Robust Concurrency Model
• “processes” – extreme lightweight units of
concurrency
• Garbage collection is per process
- No global pauses
• Load balances on IO and CPU

20. Channels
Trivial realtime communication for
connected devices

27. But there is more ..
• Form builders
• Static build tools with ES6 by default
• Live reloading
• First class test tools
• Packages via hex.pm (+2MM downloads)

28. Applications
• Package and run our code
• Can be started and stopped as a unit
• Provide unified configuration
• Hold processes and state in the
supervision tree

29. :observer.start

30. :observer.start

34. • The ONVIF specification defines a common
protocol for the exchange of information
between network video devices including
automatic device discovery, video streaming
and intelligence metadata.

35. Onvif Specification
Based on relevant Web Services standards including security
and IP configuration requirements. Areas covered:
• IP configuration
• Device discovery
• Device management
• Media configuration
• Real time viewing
• Event handling
• PTZ camera control
• Video analytics
• Security

36. http://www.onvif.org/onvif/ver20/util/operationIndex.html

37. Integration with evercam-media
Problems:
• Poor SOAP support in Erlang/Elixir.
• WS-Security not implemented.
• SOAP operations return XML.
• evercam-media needs JSON responses.

38. Integration with evercam-media
Solution:
• HTTPotion for HTTP requests

40. Integration with evercam-media
Solution:
• HTTPotion for HTTP requests
• Own implementation of SOAP Envelope and
WS-Security headers.

43. Integration with evercam-media
Solution:
• HTTPotion for HTTP requests
• Own implementation of SOAP Envelope and
WS-Security headers.
• Own implementation of XML to Elixir Map
transformations using Erlang xmerl library

45. Integration with evercam-media
• Definition of needed operations using
onvif_client methods.

47. Integration with evercam-media
• Definition of needed operations using
onvif_client methods.
• Add REST routes to web/router.ex

50. Integration with evercam-media
• Definition of needed operations using
onvif_client methods.
• Add REST routes to web/router.ex
• Implement controllers that will invoke ONVIF
operations and return the responses as Elixir
Map structures.

52. Integration with evercam-media
• Definition of needed operations using
onvif_client methods.
• Add REST routes to web/router.ex
• Implement controllers that will invoke ONVIF
operations and return the responses as Elixir
Map structures.
• Phoenix translate these Maps into JSON
structures without the need of extra coding

54. Demo