go-start - A high level webframework for Go

GTUG Vienna 27.3.2012 presentation

go get github.com/ungerik/go-start

Transcript

1. go-start A high level web-framework for Go Mittwoch, 28. März 12
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 Mittwoch, 28. März 12
3. Current status • In development for 10 months • Work sponsored by STARTeurope • Used in production for http://startuplive.in • Go v1.0 Mittwoch, 28. März 12
4. What’s in it? • MVC • Prefer Go syntax to template languages • HTML5 Boilerplate out of the box • MongoDB • All batteries included Mittwoch, 28. März 12
5. All batteries included • HTML5 Boilerplate • jQuery • External dependencies fetched automatically: go get -u github.com/ungerik/go-start Mittwoch, 28. März 12
6. Views Mittwoch, 28. März 12
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 Mittwoch, 28. März 12
8. Higher level abstractions •view.List •view.Table •view.Form •view.ModelView •view.If •view.Menu •view.Video •view.Page Mittwoch, 28. März 12
9. HTML Tags / Shortcuts •H1, H2, ... •P •Pre •A, A_blank •Img •Br •B, I, Q •Em, Strong •Ul, Ol Mittwoch, 28. März 12
10. So how does a view look like? Mittwoch, 28. März 12
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 ! ! }, ! }, } Mittwoch, 28. März 12
12. Yes, templates are supported Mittwoch, 28. März 12
13. But I ended up using them only for the HTML5 Boilerplate Page template Mittwoch, 28. März 12
14. Dynamic Views Mittwoch, 28. März 12
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 ! }, ) Mittwoch, 28. März 12
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 ! }, } Mittwoch, 28. März 12
17. HTML Pages Mittwoch, 28. März 12
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{}, } Mittwoch, 28. März 12
19. URL structure Mittwoch, 28. März 12
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 ! ! }}, ! } } Mittwoch, 28. März 12
21. Running the server Mittwoch, 28. März 12
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") Mittwoch, 28. März 12
23. Models Mittwoch, 28. März 12
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 Mittwoch, 28. März 12
25. FormModel Mittwoch, 28. März 12
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 ! }, } Mittwoch, 28. März 12
27. mongo.Document Mittwoch, 28. März 12
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"` ! } } Mittwoch, 28. März 12
29. mongo.Collection Mittwoch, 28. März 12
30. var ExampleDocs *mongo.Collection = mongo.NewCollection("exampledocs", (*ExampleDoc)(nil)) Mittwoch, 28. März 12
31. mongo.Query Mittwoch, 28. März 12
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()) } Mittwoch, 28. März 12
33. Create, modify, save a mongo.Document Mittwoch, 28. März 12
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() Mittwoch, 28. März 12
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) Mittwoch, 28. März 12
36. Where to get it • go get -u github.com/ungerik/go-start • Documentation: http://go-start.org/ Mittwoch, 28. März 12
37. One more thing ;-) Mittwoch, 28. März 12
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40. We are hiring! STARTeurope Mittwoch, 28. März 12
41. Go+Javascript Pioneers (Vienna) Mittwoch, 28. März 12
42. The End Questions? • erik.unger@starteurope.at • Twitter: @ungerik • Skype: ungerik Mittwoch, 28. März 12