refactor to introduce a simplistic URL router, logging, and html templates with a data driven table

johnpfeiffer · johnpfeiffer · commit c8636ee4f54f · 2018-05-08T22:33:08.000-07:00
diff --git a/hexcolors.go b/hexcolors.go
@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"html/template"
+	"net/http"
+)
+
+// HexColors wraps a list of colors as hexadecimal strings
+type HexColors struct {
+	Colors []string
+}
+
+// GetHexTemplate returns the parsed file as a template object
+func GetHexTemplate() *template.Template {
+	return template.Must(template.ParseFiles("hexcolorstemplate.html"))
+}
+
+func hexController(w http.ResponseWriter, r *http.Request) {
+	colors := []string{}
+	for i := 255; i <= 16711680; i = i * 256 {
+		s := fmt.Sprintf("%06X", i)
+		colors = append(colors, s)
+	}
+	data := HexColors{colors}
+	hexTemplate.Execute(w, data)
+}
diff --git a/hexcolorstemplate.html b/hexcolorstemplate.html
@@ -0,0 +1,16 @@
+<html>
+  <head><style>
+        table, th, td {
+    border: 2px solid black;
+  }
+  </style></head>
+  <body>
+  <table>
+    {{range .Colors}}
+    <tr>
+      <td>{{.}}</td><td style="background-color: {{.}}; ">__</td>
+    </tr>
+    {{end}}
+    </table>
+</body>
+</html>
diff --git a/indextemplate.go b/indextemplate.go
@@ -19,7 +19,7 @@ body{
 </style>
 </head>
 <body>
-hi
+hi , try <a href="/hexcolors">hexcolors</a>
 </body>
 </html>
 `))
diff --git a/main.go b/main.go
@@ -4,18 +4,28 @@ import (
 	"log"
 	"net/http"
 	"os"
+	"strings"
 )
 
+// TODO: globals are evil - there is a better way
 var indexTemplate = GetIndexTemplate()
+var hexTemplate = GetHexTemplate()
 
-func myHandler(w http.ResponseWriter, r *http.Request) {
-	indexTemplate.Execute(w, NoData{})
+func myRouter(w http.ResponseWriter, r *http.Request) {
+	if !strings.Contains(r.URL.Path, "favicon") {
+		log.Println(r.URL.Path)
+	}
+	if strings.ToLower(r.URL.Path) == "/hexcolors" {
+		hexController(w, r)
+	} else {
+		indexTemplate.Execute(w, NoData{})
+	}
 }
 
 func main() {
 	port := getEnvOrDefault("PORT", "8080")
 	log.Println("Listening on port", port)
-	http.HandleFunc("/", myHandler)
+	http.HandleFunc("/", myRouter)
 	http.ListenAndServe(":"+port, nil)
 }
 
