render.go

package page

import (
	"html/template"
	"io"
)

// HTML render some html with added template functions to support components. This
// passes the component state to be rendered.
//
// Template functions
// - "Event" takes an event string and scopes it for the component.
func HTML(layout string, c *Component) RenderFunc {
	t := template.Must(template.New("").Funcs(templateFuncs(c)).Parse(layout))
	return RenderFunc(func(w io.Writer) error {
		if err := t.Execute(w, c.State); err != nil {
			return err
		}
		return nil
	})
}

func templateFuncs(c *Component) template.FuncMap {
	return template.FuncMap{
		"Event": c.Event,
	}
}

// RenderFunc a helper function to ease the rendering of nodes.
type RenderFunc func(io.Writer) error

// Render take a writer and render the func.
func (r RenderFunc) Render(w io.Writer) error {
	return r(w)
}

// RenderComponent wrap a component and provide a RenderFunc.
func RenderComponent(c Component) RenderFunc {
	return RenderFunc(func(w io.Writer) error {
		return c.Render(w, &c)
	})
}