make the service a http.Handler

README.md

@@ -4,11 +4,20 @@
 [![GoDoc](https://pkg.go.dev/badge/github.com/emicklei/structexplorer)](https://pkg.go.dev/github.com/emicklei/structexplorer)
 [![codecov](https://codecov.io/gh/emicklei/structexplorer/branch/master/graph/badge.svg)](https://codecov.io/gh/emicklei/structexplorer)
 
-A Go Struct Explorer Service that offers a remote (HTTP) inspection of any Go struct.
+A Go Struct Explorer Service (http.Handler) that offers remote inspection of any Go struct and its references.
+
+## install
+
+    go get github.com/emicklei/structexplorer
 
 ## usage
 
-    structexplorer.NewService("some structure", aStruct).Start()
+    structexplorer.NewService("some structure", yourStruct).Start()
+
+or as HTTP Handler:
+
+    s := structexplorer.NewService("some structure", yourStruct)
+    http.ListenAndServe(":8080", s)
 
 then a HTTP service will be started
 
@@ -26,7 +35,12 @@ then a HTTP service will be started
 - z : show or hide fields which currently have zero value ("",0,nil,false)
 - x : remove the struct from the page
 
+Note: if the list contains just one structural value then selecting it can be skipped for ⇊ and ⇉.
+
+## examples
+
+See folder `examples` for simple programs.
 
-## Example of exploring a [yaegi](https://github.com/traefik/yaegi) program
+### example of exploring a [yaegi](https://github.com/traefik/yaegi) program
 
 ![program](./doc/explore_yaegi.png "Yaegi explore")

examples/handler/main.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/emicklei/structexplorer"
+)
+
+func main() {
+	log.Println("use service as handler on http://localhost:8080")
+	http.ListenAndServe(":8080", structexplorer.NewService("test", time.Now()))
+}

examples/inside_test/README.md

@@ -0,0 +1 @@
+![test](../doc/testingT.png "explore the tester")

examples/inside_test/inside_test.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/emicklei/structexplorer"
+)
+
+func TestExplore(t *testing.T) {
+	// lets explore the "t" ; do it within 30 seconds before it timeouts
+	structexplorer.NewService("testing.T", t).Start()
+}

script.js

@@ -5,7 +5,7 @@ function explore(row, column, selectNode, action) {
     }
     console.log(row, column, selectNode.value, action);
     const xhr = new XMLHttpRequest();
-    xhr.open("POST", instructionURL(window.location.href));
+    xhr.open("POST", window.location.href);
     xhr.setRequestHeader("Content-Type", "application/json; charset=UTF-8")
     xhr.send(JSON.stringify({
         row: row,
@@ -15,9 +15,6 @@ function explore(row, column, selectNode, action) {
     }));
     xhr.onload = function () { window.location.reload(); }
 }
-function instructionURL(href) {
-    return href.endsWith("/") ? href + "instructions" : href + "/instructions";
-}
 // Return an array of the selected option values in the control.
 // Select is an HTML select element.
 function getSelectValues(select) {
@@ -32,5 +29,9 @@ function getSelectValues(select) {
             result.push(opt.value || opt.text);
         }
     }
+    if (result.length == 0 && options.length == 1) {
+        opt = options[0];
+        result.push(opt.value || opt.text);
+    }
     return result;
 }

service.go

@@ -85,31 +85,45 @@ type service struct {
 	indexTemplate *template.Template
 }
 
-// Service is the HTTP service to explore one or more values (structures).
+// Service is an HTTP Handler to explore one or more values (structures).
 type Service interface {
+	http.Handler
 	// Start accepts 0 or 1 Options
 	Start(opts ...Options)
 }
 
 // NewService creates a new to explore one or more values (structures).
 func NewService(labelValuePairs ...any) Service {
-	return &service{explorer: newExplorerOnAll(labelValuePairs...)}
+	s := &service{explorer: newExplorerOnAll(labelValuePairs...)}
+	s.init()
+	return s
 }
 
-// Start accepts 0 or 1 Options, implements Service
+// Start will listen and serve on the given http port and path.
+// it accepts 0 or 1 Options to override defaults.
 func (s *service) Start(opts ...Options) {
 	if len(opts) > 0 {
 		s.explorer.options = &opts[0]
 	}
-	s.init()
 	port := s.explorer.options.httpPort()
 	serveMux := s.explorer.options.serveMux()
 	rootPath := s.explorer.options.rootPath()
 	slog.Info(fmt.Sprintf("starting go struct explorer at http://localhost:%d%s on %v", port, rootPath, s.explorer.rootKeys()))
-	serveMux.HandleFunc(rootPath, s.serveIndex)
-	serveMux.HandleFunc(path.Join(rootPath, "/instructions"), s.serveInstructions)
+	serveMux.Handle(rootPath, s)
 	if err := http.ListenAndServe(fmt.Sprintf(":%d", port), nil); err != nil {
-		slog.Error("failed to start server", "err", err)
+		slog.Error("failed to start service", "err", err)
+	}
+}
+
+// ServeHTTP implements http.Handler
+func (s *service) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		s.serveIndex(w, r)
+	case http.MethodPost:
+		s.serveInstructions(w, r)
+	default:
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 	}
 }
 
@@ -130,10 +144,6 @@ type uiInstruction struct {
 }
 
 func (s *service) serveInstructions(w http.ResponseWriter, r *http.Request) {
-	if r.Method != http.MethodPost {
-		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
-		return
-	}
 	cmd := uiInstruction{}
 	if err := json.NewDecoder(r.Body).Decode(&cmd); err != nil {
 		http.Error(w, err.Error(), http.StatusBadRequest)
@@ -153,8 +163,7 @@ func (s *service) serveInstructions(w http.ResponseWriter, r *http.Request) {
 		if s.explorer.canRemoveObjectAt(cmd.Row, cmd.Column) {
 			s.explorer.removeObjectAt(cmd.Row, cmd.Column)
 		} else {
-			o := s.explorer.objectAt(cmd.Row, cmd.Column)
-			slog.Warn("cannot remove root struct", "object", o.label, "row", cmd.Row, "column", cmd.Column)
+			slog.Warn("cannot remove root struct", "object", fromAccess.label, "row", cmd.Row, "column", cmd.Column)
 		}
 		return
 	case "toggleZeros":