This document summarizes a high level web framework called go-start that was created for the Go programming language. Some key points: - It aims to provide a high level framework like Django or Rails that is easy to setup and deploy while staying true to Go conventions. - It uses MVC architecture and prefers Go syntax over template languages for views. It includes HTML5 Boilerplate, jQuery and handles external dependencies. - Views can be defined using Go syntax and DOM representations on the server. Common widgets like lists, tables and forms are provided at a higher level. - Models are Go structs with validation via reflection and shared between forms and the MongoDB database. - Routing

1. go-start
A high level web-framework for Go

2. Goals
• Create a high level web-framework for Go,
like Django for Python or Rails for Ruby
• Be Go-ish
• Don’t make stuff more complicated than it
has to be
• Convention over configuration
• Easy setup and deployment

3. Current status
• In development for 10 months
• Work sponsored by STARTeurope
• Used in production for http://startuplive.in
• Go v1.0

4. What’s in it?
• MVC
• Prefer Go syntax to template languages
• HTML5 Boilerplate out of the box
• MongoDB
• All batteries included

5. All batteries included
• HTML5 Boilerplate
• jQuery
• External dependencies fetched
automatically:
go get -u github.com/ungerik/go-start

6. Views

7. Philosophy
• Why learn another template language if you
can use Go syntax?
• DOM tree has a 1:1 Go object
representation on the server
• Every element has an ID to enable sync of
DOM tree and server view representation

8. Higher level abstractions
• view.List • view.Menu
• view.Table • view.Video
• view.Form • view.Page
• view.ModelView
• view.If

9. HTML Tags / Shortcuts
• H1, H2, ... • Br
•P • B, I, Q
• Pre • Em, Strong
• A, A_blank • Ul, Ol
• Img

10. So how does a view look
like?

11. view := Views{
! NewDiv("myclass",
! ! H1("Example HTML structure"),
! ! P("This is a paragraph"),
! ! P(
! ! ! HTML("Some unescaped HTML:<br/>"),
! ! ! Printf("The number of the beast: %d", 666),
! ! ! Escape("Will be escaped: 666 < 999"),
! ! ),
! ! A_blank("http://go-lang.org", "A very simple link"),
! ),
! Hr(),
! Pre("! <- pre formated text, followed by a list:"),
! Ul("red", "green", "blue"),
! &Template{
! ! Filename: "mytemplate.html",
! ! GetContext: func(ctx *Context) (interface{}, error) {
! ! ! return map[string]string{"Key": "Value"}, nil
! ! },
! },
}

12. Yes, templates are
supported

13. But I ended up using them
only for the HTML5
Boilerplate Page template

14. Dynamic Views

15. view := NewDynamicView(
! func(context *Context) (view View, err error) {
! ! var names []string
! ! i := models.Users.Sort("Name.First").Sort("Name.Last").Iterator();
! ! for doc := i.Next(); doc != nil; doc = i.Next() {
! ! ! names = append(names, doc.(*models.User).Name.String())
! ! }
! ! if i.Err() != nil {
! ! ! return nil, i.Err()
! ! }! ! !
! ! return &List{! // List = higher level abstraction, Ul() = shortcut
! ! ! Class: "my-ol",
! ! ! Ordered: true,
! ! ! Model: EscapeStringsListModel(names),
! ! }, nil
! },
)

16. view := &ModelView{
! GetModelIterator: func(context *Context) model.Iterator {
! ! return models.Users.Sort("Name.First").Sort("Name.Last").Iterator()
! },
! GetModelView: func(model interface{}, context *Context) (view View, err error) {
! ! user := model.(*models.User)
! ! return PrintfEscape("%s, ", user.Name), nil
! },
}

17. HTML Pages

18. Homepage := &Page{
! OnPreRender: func(page *Page, context *Context) (err error) {
! ! context.Data = &PerPageData{...} // Set global page data at request context
! },
! WriteTitle: func(context *Context, writer io.Writer) (err error) {
! ! writer.Write([]byte(context.Data.(*PerPageData).DynamicTitle))
! ! return nil
! },
! CSS: HomepageCSS,
! WriteHeader: RSS("go-start.org RSS Feed", &RssFeed)
! WriteScripts: PageWriters(
! ! Config.Page.DefaultWriteScripts,
! ! JQuery, // jQuery/UI is built-in
! ! JQueryUI,
! ! JQueryUIAutocompleteFromURL(".select-username", IndirectURL(&API_Usernames), 2),
! ! GoogleAnalytics(GoogleAnalyticsID), // Google Analytics is built-in
! )
! Content: Views{},
}

19. URL structure

20. Admin_Auth := NewBasicAuth("go-start.org", "admin", "password123")
func Paths() *ViewPath {
! return &ViewPath{View: Homepage, Sub: []ViewPath{ // /
! ! {Name: "style.css", View: HomepageCSS}, // /style.css
! ! {Name: "feed", View: RssFeed}, // /feed/
! ! {Name: "admin", View: Admin, Auth: Admin_Auth, Sub: []ViewPath{ // /admin/
! ! ! {Name: "user", Args: 1, View: Admin_User, Auth: Admin_Auth},// /admin/user/<ID>/
! ! }},
! ! {Name: "api", Sub: []ViewPath{ // 404 because no view defined
! ! ! {Name: "users.json", View: API_Usernames}, // /api/users.json
! ! }},
! }
}

21. Running the server

22. view.Init("go-start.org", CookieSecret, "pkg/myproject", "pkg/
gostart")
view.Config.RedirectSubdomains = []string{"www"}
view.Config.Page.DefaultMetaViewport = "width=960px"
view.RunConfigFile(Paths(), "run.config")

23. Models

24. Models
• Models are Go structs
(marshaling via reflection)
• Meta information for validation and display
is added via tags
• Forms and DB share the same model and
validation mechanism
• MongoDB is the default database

25. FormModel

26. type SignupFormModel struct {
! Email model.Email `gostart:"required"`
! Password1 model.Password `gostart:"required|label=Password|minlen=6"`
! Password2 model.Password `gostart:"label=Repeat password"`
}
func (self *SignupFormModel) Validate(metaData model.MetaData) []*model.ValidationError {
! if self.Password1 != self.Password2 {
! ! return model.NewValidationErrors(os.NewError("Passwords don't match"), metaData)
! }
! return model.NoValidationErrors
}
form := &Form{
! ButtonText: "Signup",
! FormID: "user_signup",
! GetModel: func(form *Form, context *Context) (interface{}, error) {
! ! return &SignupFormModel{}, nil
! },
! OnSubmit: func(form *Form, formModel interface{}, context *Context) (err error) {
! ! m := formModel.(*SignupFormModel)
! ! // ... create user in db and send confirmation email ...
! ! return err
! },
}

27. mongo.Document

28. type ExampleDoc struct {
! mongo.DocumentBase `bson:",inline"` // Give it a Mongo ID
! Person mongo.Ref `gostart:"to=people"` // Mongo ID ref to a document in
"people" collection
! LongerText model.Text `gostart:"rows=5|cols=80|maxlen=400"`
! Integer model.Int `gostart:"min=1|max=100"`
! Email model.Email // Normalization + special treament in forms
! PhoneNumber model.Phone // Normalization + special treament in forms
! Password model.Password // Hashed + special treament in forms
! SubDoc struct {
! ! Day model.Date
! ! RealFloat model.Float `gostart:"valid"
! ! Drinks []mongo.Choice `gostart:"options=Beer,Wine,Water"`
! }
}

29. mongo.Collection

30. var ExampleDocs *mongo.Collection = mongo.NewCollection("exampledocs", (*ExampleDoc)(nil))

31. mongo.Query

32. i := models.Users.Filter("Name.Last", "Smith").Sort("Name.First").Iterator();
for doc := i.Next(); doc != nil; doc = i.Next() {
! user := doc.(*models.User)
! // ...
}
// Err() returns any error after Next() returned nil:
if i.Err() != nil {
! panic(i.Err())
}

33. Create, modify, save a
mongo.Document

34. user := models.Users.NewDocument().(*models.User)
user.Name.First.Set("Erik")
user.Name.Last.Set("Unger")
doc, err := models.Groups.Filter(“Name”, “testgroup”).One()
group := doc.(*models.Group)
user.Group.Set(group) // sets a mongo.Ref to the group
!
err := user.Save()

35. Additional packages
• Email (message creation missing in standard
mail package + Google Mail defaults)
• Gravatar
• RSS parsing
• Amiando event management
(used by http://startuplive.in)

36. Where to get it
• go get -u github.com/ungerik/go-start
• Documentation: http://go-start.org/

37. One more thing ;-)

40. We are hiring!
STARTeurope

41. Go+Javascript Pioneers
(Vienna)

42. The End
Questions?
• erik.unger@starteurope.at
• Twitter: @ungerik
• Skype: ungerik