pgenr/render.go

package pgenr

import (
	"bytes"
	"git.nspix.com/golang/pgenr/theme"
	"github.com/vanng822/go-premailer/premailer"
	"net/http"
	"text/template"
)

const (
	Name = "pgenr"
)

type (
	RenderOption func(o *RenderOptions)

	Template struct {
		Page *Page
	}

	RenderOptions struct {
		Theme     theme.Theme
		InlineCss bool
	}
)

func Render(page *Page, cbs ...RenderOption) (str string, err error) {
	var (
		tpl     *template.Template
		buffer  bytes.Buffer
		cssProc premailer.Premailer
	)
	opts := &RenderOptions{
		Theme:     &theme.Default{},
		InlineCss: false,
	}
	for _, cb := range cbs {
		cb(opts)
	}
	if tpl, err = template.New(Name).Parse(opts.Theme.Template()); err != nil {
		return
	}
	if err = tpl.Execute(&buffer, Template{page}); err != nil {
		return
	}
	if !opts.InlineCss {
		str = buffer.String()
		return
	}
	if cssProc, err = premailer.NewPremailerFromBytes(buffer.Bytes(), premailer.NewOptions()); err != nil {
		return
	}
	str, err = cssProc.Transform()
	return
}

func Response(page *Page, w http.ResponseWriter, cbs ...RenderOption) (err error) {
	var (
		html string
	)
	if html, err = Render(page, cbs...); err == nil {
		_, err = w.Write([]byte(html))
	}
	return
}