Quickstart

A Simple Application

To get started with a simple Golf application, create a file named app.go:

package main

import "github.com/dinever/golf"

func helloWorldHandler(ctx *Golf.Context) {
    ctx.Write("Hello World!")
}

func main() {
    app := Golf.New()
    app.Get("/", helloWorldHandler)
    app.Run(":9000")
}

And run the application by using the go compiler:

$ go run main.go

Then you should be able to see the result if you take a look at http://localhost:9000.

Routing

Routing in Golf is easy. Here are some examples:

App.Get("/", HomeHandler)
App.Get("/p/:page/?", PageHandler)
App.Post("/comment/:id/", CommentHandler)

In the above example, we added 3 routing rules. They are:

• HTTP GET method on the path /. If user visits http://example.com/, the request will be passed to HomeHandler.
• HTTP GET method on the path /p/:page/?. Every request with a path matching this routing rule, e.g. /p/1/, /p/101/ or /p/12345 will be passed to PageHandler, and what user inputed in the page field will be stored in ctx.Params. Please notice that the last question mark ? in the routing rule means that the previous / is optional, and both /p/123/ and /p/123 can be matched.
• HTTP POST method on the path /comment/:id/. This is similar to the previous one. The only difference is that this one matches a POST method.

The parameters will be passed in ctx.Params, and can be get by this:

p, ok := ctx.Params["page"]

Other than GET and POST, you can use methods App.Put and App.Delete to handle PUT and DELETE requests.

Static Files

Static files, like stylesheets and javascript files can be handled easily by calling App.Static:

App.Static("/static/", "static")
App.Static("/static/", "resources")

The first argument is the URL path for static files, the second argument is the path of the folder holding static files on your filesystem. Please notice that Golf supports serving multiple folders into one URL root PATH, which means that if you set Golf like the above example, when user requested /static/style.css, Golf will firstly lookup the file style.css in the folder static, and continue looking up the same file in the folder resources if it is not found in the previous folder.

Rendering Templates

If you are familiar with the Django/Jinja2 style template syntax, it may not comfortable for you to get in touch with the Go style template, especially the template inheritence part. However, using Golf you can handle it like a charm. Let’s take a look at an example:

main.go:

package main

import (
  "github.com/dinever/golf"
)

func homeHandler(ctx *Golf.Context) {
  data := map[string]interface{}{
    "Title": "Hello World",
  }
  ctx.Loader("template").Render("index.html", data)
}

func main() {
  App := Golf.New()
  App.View.SetTemplateLoader("template", "templates/")
  App.Get("/", homeHandler)
  App.Run(":9000")
}

templates/index.html:

<h1>{{ .Title }}</h1>

The first step is to indicating a template loader for App.View. The first argument is the name of the template loader, the second argument is the path of the template folder. Golf allows you to indicating multiple template loaders, e.g., one for the templates of admin panel and another one for the templates of front-end.

After the template loader is set, you can render templates inside the loader by calling ctx.Loader("loader_name").Render("file_name", data). Indicating a template loader before calling Render is necessary, otherwise Golf can not find out the template file.

Redirection

Simple call ctx.Redirect with the path as an argument. By default Golf set the status code to 301. If you want a 302 Redirection, please manually set the header as 302 after calling ctx.Redirect.

ctx.Redirect("/foo")

Error Handling

You can use Golf.Error to set handlers for different type of errors like the following:

App.Error(401, unauthorizedHandler)
App.Error(404, notFoundHandler)

To raise an error inside context, please use the method Context.Abort:

func homeHandler(ctx *Golf.Context) {
  user, e := getUser()
  if e != nil {
    ctx.Abort(401)
    return
  }
  ctx.Loader("template").Render("index.html", data)
}

Golf will find the corresponding error handler in the error handler map. If the error handler for this status code is not set, golf calls App.DefaultErrorHandler.

You can also indicate a DefaultErrorHandler by yourself.

App.DefaultErrorHandler = errorHandler