go-start @ Google DevFest Vienna 2012

http://www.devfest.at/session/the-go-start-web-framework

Transcript

1. go-start A high level web-framework for Go Mittwoch, 14. November 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, 14. November 12
3. Current status • In development for over a year • Work sponsored by STARTeurope • Used in production for http://startuplive.in • Go v1.0 Mittwoch, 14. November 12
4. What’s in it? • MVC • Prefer Go syntax to template languages • HTML5 Boilerplate out of the box • MongoDB • All batteries included Mittwoch, 14. November 12
5. All batteries included • HTML5 Boilerplate • jQuery • External dependencies fetched automatically: go get -u github.com/ungerik/go-start Mittwoch, 14. November 12
6. Views Mittwoch, 14. November 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, 14. November 12
8. Higher level abstractions •view.List •view.Table •view.Form •view.ModelView •view.If •view.Menu •view.Video •view.Page Mittwoch, 14. November 12
9. HTML Tags / Shortcuts •H1, H2, ... •P •Pre •A, A_blank •Img •Br •B, I, Q •Em, Strong •Ul, Ol Mittwoch, 14. November 12
10. So how does a view look like? Mittwoch, 14. November 12
11. view := Views{ ! DIV("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, 14. November 12
12. Yes, templates are supported Mittwoch, 14. November 12
13. But I ended up using them only for the HTML5 Boilerplate Page template Mittwoch, 14. November 12
14. Dynamic Views Mittwoch, 14. November 12
15. view := DynamicView( ! func(ctx *Context) (View, error) { ! ! if ctx.Request.RequestURI == "/" { ! ! ! // return nil, so nothing will be rendered ! ! ! return nil, nil ! ! } ! ! return A("/", HTML("&larr; Back to the homepage")), nil ! }, ) Mittwoch, 14. November 12
16. HTML Pages Mittwoch, 14. November 12
17. Homepage := &Page{ ! OnPreRender: func(page *Page, context *Context) (err error) { ! ! context.Data = &PerPageData{...} // Set global page data at request context ! }, ! Title: func(context *Context, writer io.Writer) (err error) { ! ! writer.Write([]byte(context.Data.(*PerPageData).DynamicTitle)) ! ! return nil ! }, ! CSS: HomepageCSS, ! AdditionalHead: RSS("go-start.org RSS Feed", &RssFeed) ! Scripts: Renderers{ ! ! 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, 14. November 12
18. URL structure Mittwoch, 14. November 12
19. var ( ! CSS View ! Homepage ViewWithURL ! ... ) func Paths() *ViewPath { ! return &ViewPath{View: Homepage, Sub: []ViewPath{ ! ! media.ViewPath("media"), ! ! {Name: "style.css", View: CSS}, ! ! ... ! }} } Mittwoch, 14. November 12
20. Models Mittwoch, 14. November 12
21. 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, 14. November 12
22. FormModel Mittwoch, 14. November 12
23. 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, 14. November 12
24. Where to get it • go get github.com/ungerik/go-start • Tutorial: https://github.com/ungerik/go-start/tree/master/ examples/FullTutorial • Documentation: http://go.pkgdoc.org/github.com/ungerik/go-start Mittwoch, 14. November 12
25. The End Questions? • erik@erikunger.com • Twitter: @ungerik • Skype: ungerik Mittwoch, 14. November 12