server_assets.go

package main

import (
	"encoding/json"
	"fmt"
	"github.com/gin-gonic/gin"
	"html/template"
	"io/ioutil"
	"net/http"
	"path"
	"strings"
)

var functionMap = template.FuncMap{
	"raw": func(b []byte) template.HTML {
		return template.HTML(b)
	},
	"stringify": func(input interface{}) string {
		buffer, err := json.Marshal(input)
		if err != nil {
			return `""`
		}
		return string(buffer)
	},
	"keycombo": func(input string) string {
		if len(input) > 0 {
			return strings.Replace(input, ",", " + ", -1)
		}
		return "Not Assigned"
	},
}

func loadEmbedded() (*template.Template, error) {
	t := template.New("")
	for name, file := range Assets.Files {
		if file.IsDir() || !strings.HasSuffix(name, ".tmpl") {
			continue
		}
		h, err := ioutil.ReadAll(file)
		if err != nil {
			return nil, err
		}
		t, err = t.New(path.Base(name)).Funcs(functionMap).Parse(string(h))
		if err != nil {
			return nil, err
		}
	}
	return t, nil
}

func loadAsset(file string) ([]byte, error) {
	asset, err := Assets.Open("/assets/static/" + file)
	if err != nil {
		return nil, nil
	}
	content, err := ioutil.ReadAll(asset)
	if err != nil {
		return nil, err
	}
	return content, nil
}

func setupTemplate(assets string, router *gin.Engine) (string, string) {
	var static, templates string
	if len(assets) > 0 {
		fmt.Println("debugging assets.")
		static = path.Join(assets, "static")
		templates = path.Join(assets, "templates", "*")
		router.SetFuncMap(functionMap)
		router.LoadHTMLGlob(templates)
	} else {
		templates, err := loadEmbedded()
		if err != nil {
			panic(err)
		}
		router.SetHTMLTemplate(templates)
	}
	return static, templates
}

func serverAddAssets(root *gin.RouterGroup, assets, static, templates string) {
	if len(assets) > 0 {
		root.GET("/favicon.ico", func(c *gin.Context) {
			c.Redirect(302, "/static/favicon.ico")
		})
		root.Static("/static", static)
	} else {
		root.GET("/favicon.ico", func(c *gin.Context) {
			content, err := loadAsset("favicon.ico")
			if content == nil && err == nil {
				c.Status(404)
				return
			} else if err != nil {
				c.Status(500)
				fmt.Println("[Assets]", err)
				return
			}
			c.Data(200, "image/x-icon", content)
		})
		root.GET("/static/:file", func(c *gin.Context) {
			file := c.Param("file")
			content, err := loadAsset(file)
			if content == nil && err == nil {
				c.Status(404)
				return
			} else if err != nil {
				c.Status(500)
				fmt.Println("[Assets]", err)
				return
			}
			var contentType = "text/plain"
			if strings.HasSuffix(file, ".css") {
				contentType = "text/css"
			} else if strings.HasSuffix(file, ".js") {
				contentType = "text/javascript"
			} else {
				contentType = http.DetectContentType(content)
			}
			c.Data(200, contentType, content)
		})
	}
}