redirects.go

package main

import (
	"bytes"
	"log"
	"net/http"
)

var redirectPages = map[[2]string][2]string{
	{"fundamentals", "go-sdk.html"}:     {"fundamentals", "go-toolchain.html"},
	{"fundamentals", "tools.html"}:      {"apps-and-libs", "101.html"},
	{"fundamentals", "tool-gold.html"}:  {"apps-and-libs", "golds.html"},
	{"fundamentals", "tool-golds.html"}: {"apps-and-libs", "golds.html"},
}

func (go101 *Go101) RedirectArticlePage(w http.ResponseWriter, r *http.Request, group, file string) bool {
	redirectPage, ok := redirectPages[[2]string{group, file}]
	if ok {
		page, isLocal := go101.articlePages.Get(group, file), go101.IsLocalServer()
		if page == nil {
			pageParams := map[string]interface{}{
				"RedirectPage": "/" + redirectPage[0] + "/" + redirectPage[1],
				//"IsLocalServer": isLocal,

				//"Value": func() func(string, ...interface{}) interface{} {
				//	var kvs = map[string]interface{}{}
				//	return func(k string, v ...interface{}) interface{} {
				//		if len(v) == 0 {
				//			return kvs[k]
				//		}
				//		kvs[k] = v[0]
				//		return ""
				//	}
				//}(),
			}

			t := retrievePageTemplate(Template_Redirect, !isLocal)
			var buf bytes.Buffer
			if err := t.Execute(&buf, pageParams); err == nil {
				page = buf.Bytes()
			} else {
				page = []byte(err.Error())
			}

			if !isLocal {
				go101.articlePages.Set(group, file, page)
			}
		}

		if len(page) == 0 { // blank page means page not found.
			log.Printf("article page %s/%s is not found", group, file)
			//w.Header().Set("Cache-Control", "no-cache, private, max-age=0")
			http.Redirect(w, r, "/article/101.html", http.StatusNotFound)
		} else if isLocal {
			w.Header().Set("Cache-Control", "no-cache, private, max-age=0")
		} else {
			w.Header().Set("Cache-Control", "max-age=50000") // about 14 hours
		}
		w.Write(page)
	}

	return ok
}