Explain why I choose Go for building large website with actual examples.

1. Why use Go for Web
development?
Weng Wei, July 2014

2. About Go

3. –Rob Pike
“Go is a programming language designed by Google to help solve
Google's (big)problems. ”

4. –Derek Collison
“ Go will become the dominant language for systems work in IaaS,
Orchestration, and PaaS in 24 months.”

5. Go looks cool！
but, it is suitable for simple web development?

6. Web? Use MVC！
• Quite a number of Go MVC web framework exist:
• Beego / Martini / Revel….
• Different approach for MC layers
• V layer are mostly the same: Go HTML Template http://golang.org/
pkg/html/template/

7. @yinwang0：Go HTML Template
• “Basically usable” template engine
• Surprisingly, logic control code in template are not Go itself
• Poor expressiveness
• Need to bind all template data into a single model
• Helper func need to be “registerd”
• Quite messy & tedious

8. –Wang Yin
“It’s better to build website with more mature frameworks from
other language”

9. Template engine must be good
for web development!

10. – Wikipedia
“PHP(PHP: Hypertext Preprocessor)…server-side scripting
language designed for web development.. PHP code can be
simply mixed with HTML code..”

11. Mix html with Go?

12. • “Not possible, Go doesn’t have interpreter”
• “Go is NOT script”

13. I think otherwise
• Go is turing complete
• No things Go can’t go
• Only thing more complicated to do with Go
• Embedding static compile language in HTML are possible:
• ASP.Net

15. Razor
• Default template/view engine for ASP.NET MVC
• Support embedding c# / vb.net in HTML
• .Net developers love it (including me):
• http://www.zhihu.com/question/19973649 (Chinese link)

16. How complicated to create
GoRazor?

17. GoRazor
• http://github.com/sipin/gorazor
• PoC in one night
• Continuous team improvement：214 commits
• Proven with internal large web project

19. • Mature template engine; sublime plug-ins for syntax highlight + auto
complete
• Able use Go directly in template; no different syntax for flow control
• Powerful expressiveness
• Rendering template is calling function; models are function
parameters
• No need to register helper func, directly import in template
• Very concise & convinient

20. Demo

21. • If you think Go is not suitable for web development because of poor
template engine
• Please try https://github.com/sipin/gorazor

22. Of cause, template engine is
only the start

23. Is Go suitable for dynamic web
development？

24. Dynamic
• web is built around string
• Go is static compiled; can it：
• Obtain object properties via string?
• Invoke package/object methods via string?
• Create object via string?

25. Reflection
• Reflection could meet most of the requirements
• Check Martini

26. Issues with Go’s reflection
• Let’s put performance aside
• Tedious & complicated
• Move compilation error to runtime error: no complier check

27. Reflection is not the only way

28. Code generation approach

29. For example
• Bind HTTP Post form values to object

34. • Generate all these methods:
• NewXXXObjByID(namespace, classname, id string)
• ReadForm(params map[string]string)
• So, 600k LoC

35. • Code generation makes static compiled language feels “dynamic”
• Go can do this, so does all other languages
• But, how about the compilation speed?

36. Full Compliation

37. Incremental compilation after editing template

38. • Go’s compilation speed is amazing!
• This is a project with 600k LoC on Mid 2011 Macbook Air
• We could keep cmd + s / cmd + tab / cmd + R development pace

39. Back to dynamic
• If complication is slow, then code-gen approach hurts produtivity
• Go compile extreme fast
• Go has unique point for dynamic

40. – Rob Pike
“interfaces.. the true Go philosophy…”

41. Go’s interface
• Define class/method first
• May define interface later
• Interface query at run-time

42. Example
• Check if object has “GetUserID” method
• If so, check if current user
• If so, allow edit

44. More example
• Check if object has “IsDistributed”、“GetPersistentNode” methods
• If so, replicate object to other nodes

46. Combine the examples

49. • Go allow querying original object’s interface
• Switch between different interfaces at runtime
• Interface could be defined in new packages
• No need to put all interface combinations for different purpose at
one place

50. However, why reinventing the
web MVC wheel?

51. But！
• Simple web pages? Pick whatever you like
• Of cause including Go
• Middle size web application, like a forum?
• php / Rails / Django / asp.net are more mature
• Go also can, if you like re-inventing the wheel
• How about large website？

52. Needs for large website
• Stability rules
• Scalability & Distributed are important
• SOA architecture
• Performance are critical
• Maintainable code (With GoRazor; even the templates are strong-
typed & compiler checked)

53. • Quick prototyping, and switch technology/platform?
• Works, but these are technical debt!
• If we could owe less debt since the beginning, why not?

54. Go is suitable to development
large website!

55. Finally, I would like to talk about
Go & startup

56. Q & A

57. Reference
• https://talks.golang.org/2012/splash.slide
• http://open.qiniudn.com/go-next-c-pptx.pdf
• http://www.csdn.net/article/2012-09-14/2809984-will-go-be-the-new-go-to-
programming-lan
• http://weibo.com/1889019865/B4nx3z6GF
• http://www.yinwang.org/blog-cn/2014/04/18/golang/
• http://zh.wikipedia.org/wiki/PHP
• http://www.ituring.com.cn/article/1339