# render [](https://app.wercker.com/project/bykey/fcf6b26a1b41f53540200b1949b48dec)
Martini middleware/handler for easily rendering serialized JSON, XML, and HTML template responses.
[API Reference](http://godoc.org/github.com/martini-contrib/render)
## Usage
render uses Go's [html/template](http://golang.org/pkg/html/template/) package to render html templates.
~~~ go
// main.go
package main
import (
"github.com/go-martini/martini"
"github.com/martini-contrib/render"
)
func main() {
m := martini.Classic()
// render html templates from templates directory
m.Use(render.Renderer())
m.Get("/", func(r render.Render) {
r.HTML(200, "hello", "jeremy")
})
m.Run()
}
~~~
~~~ html
Hello {{.}}!
~~~
### Options
`render.Renderer` comes with a variety of configuration options:
~~~ go
// ...
m.Use(render.Renderer(render.Options{
Directory: "templates", // Specify what path to load the templates from.
Layout: "layout", // Specify a layout template. Layouts can call {{ yield }} to render the current template.
Extensions: []string{".tmpl", ".html"}, // Specify extensions to load for templates.
Funcs: []template.FuncMap{AppHelpers}, // Specify helper function maps for templates to access.
Delims: render.Delims{"{[{", "}]}"}, // Sets delimiters to the specified strings.
Charset: "UTF-8", // Sets encoding for json and html content-types. Default is "UTF-8".
IndentJSON: true, // Output human readable JSON
IndentXML: true, // Output human readable XML
HTMLContentType: "application/xhtml+xml", // Output XHTML content type instead of default "text/html"
}))
// ...
~~~
### Loading Templates
By default the `render.Renderer` middleware will attempt to load templates with a '.tmpl' extension from the "templates" directory. Templates are found by traversing the templates directory and are named by path and basename. For instance, the following directory structure:
~~~
templates/
|
|__ admin/
| |
| |__ index.tmpl
| |
| |__ edit.tmpl
|
|__ home.tmpl
~~~
Will provide the following templates:
~~~
admin/index
admin/edit
home
~~~
### Layouts
`render.Renderer` provides a `yield` function for layouts to access:
~~~ go
// ...
m.Use(render.Renderer(render.Options{
Layout: "layout",
}))
// ...
~~~
~~~ html
Martini Plz
{{ yield }}
~~~
`current` can also be called to get the current template being rendered.
~~~ html
Martini Plz
This is the {{ current }} page.
~~~
### Character Encodings
The `render.Renderer` middleware will automatically set the proper Content-Type header based on which function you call. See below for an example of what the default settings would output (note that UTF-8 is the default):
~~~ go
// main.go
package main
import (
"encoding/xml"
"github.com/go-martini/martini"
"github.com/martini-contrib/render"
)
type Greeting struct {
XMLName xml.Name `xml:"greeting"`
One string `xml:"one,attr"`
Two string `xml:"two,attr"`
}
func main() {
m := martini.Classic()
m.Use(render.Renderer())
// This will set the Content-Type header to "text/html; charset=UTF-8"
m.Get("/", func(r render.Render) {
r.HTML(200, "hello", "world")
})
// This will set the Content-Type header to "application/json; charset=UTF-8"
m.Get("/api", func(r render.Render) {
r.JSON(200, map[string]interface{}{"hello": "world"})
})
// This will set the Content-Type header to "text/xml; charset=UTF-8"
m.Get("/xml", func(r render.Render) {
r.XML(200, Greeting{One: "hello", Two: "world"})
})
// This will set the Content-Type header to "text/plain; charset=UTF-8"
m.Get("/text", func(r render.Render) {
r.Text(200, "hello, world")
})
m.Run()
}
~~~
In order to change the charset, you can set the `Charset` within the `render.Options` to your encoding value:
~~~ go
// main.go
package main
import (
"encoding/xml"
"github.com/go-martini/martini"
"github.com/martini-contrib/render"
)
type Greeting struct {
XMLName xml.Name `xml:"greeting"`
One string `xml:"one,attr"`
Two string `xml:"two,attr"`
}
func main() {
m := martini.Classic()
m.Use(render.Renderer(render.Options{
Charset: "ISO-8859-1",
}))
// This will set the Content-Type header to "text/html; charset=ISO-8859-1"
m.Get("/", func(r render.Render) {
r.HTML(200, "hello", "world")
})
// This will set the Content-Type header to "application/json; charset=ISO-8859-1"
m.Get("/api", func(r render.Render) {
r.JSON(200, map[string]interface{}{"hello": "world"})
})
// This will set the Content-Type header to "text/xml; charset=ISO-8859-1"
m.Get("/xml", func(r render.Render) {
r.XML(200, Greeting{One: "hello", Two: "world"})
})
// This will set the Content-Type header to "text/plain; charset=ISO-8859-1"
m.Get("/text", func(r render.Render) {
r.Text(200, "hello, world")
})
m.Run()
}
~~~
## Authors
* [Jeremy Saenz](http://github.com/codegangsta)
* [Cory Jacobsen](http://github.com/unrolled)