htmx-demo/web/web.go

package web

import (
	"errors"
	"fmt"
	"html/template"
	"net/http"
	"net/url"
	"path/filepath"
	"strconv"
	"strings"
)

var (
	counter int = 1
)

func getContacts() map[string]any {
	return map[string]any{
		"Joe":   "joe@example.com",
		"Sarah": "sarah@example.com",
		"Fred":  "fred@example.com",
	}
}

func makeContacts1(templates *template.Template) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		templates.ExecuteTemplate(w, "contacts", map[string]any{
			"contacts": getContacts(),
			"counter":  counter,
		})
		counter++
	}
}

func makeNav(templates *template.Template) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		path := strings.SplitAfterN(r.URL.Path, "/", 3)[2]
		htmlPath := r.Header.Get("Hx-Current-Url")
		u, err := url.Parse(htmlPath)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}
		htmlPath = strings.SplitAfterN(u.Path, "/", 2)[1]
		htmlPath = htmlPath[0 : len(htmlPath)-len(filepath.Ext(htmlPath))]
		num, err := strconv.Atoi(htmlPath)
		if err != nil {
			http.Error(w, err.Error(), http.StatusBadRequest)
			return
		}
		switch path {
		case "nav":
			templates.ExecuteTemplate(w, "nav", map[string]any{
				"num":  num,
				"prev": fmt.Sprintf("%02d", num-1),
				"curr": fmt.Sprintf("%2d", num),
				"next": fmt.Sprintf("%02d", num+1),
			})
		default:
			http.Error(w, path, http.StatusNotFound)
			return
		}
	}
}

func makeSearch4(templates *template.Template) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		q := r.FormValue("q")
		state := r.FormValue("state")
		raw := getContacts()
		filtered := map[string]any{}
		for k, v := range raw {
			if strings.Contains(strings.ToUpper(k), strings.ToUpper(q)) {
				filtered[k] = v
			}
		}
		templates.ExecuteTemplate(w, "contacts", map[string]any{
			"contacts": filtered,
			"state":    state,
		})
	}
}

func SetupRoutes(mux *http.ServeMux, templates *template.Template) {
	mux.Handle("/", http.FileServer(http.Dir("./web/public/")))
	mux.HandleFunc("/autonum/", makeNav(templates))
	mux.HandleFunc("/contacts", makeContacts1(templates))
	mux.HandleFunc("/search", makeSearch4(templates))
}

func UI(addr string) error {
	templates := template.Must(template.ParseGlob("./web/public/*.gohtml"))
	mux := http.NewServeMux()
	SetupRoutes(mux, templates)
	if err := http.ListenAndServe(addr, mux); err != nil {
		if !errors.Is(err, http.ErrServerClosed) {
			return fmt.Errorf("http server error %w", err)
		}
	}
	return nil
}