Refactor generate.go to make it easier to generate more files if needed.

dmitshur · dmitshur · commit be56600c05af · 2015-10-17T18:18:42.000-07:00
Also use text/template to generate the output. It scales better than
calls to io.WriteString, etc.
diff --git a/generate.go b/generate.go
@@ -4,38 +4,59 @@ package main
 
 import (
 	"bytes"
-	"io"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"net/http"
+	"text/template"
 )
 
-func gen() error {
-	resp, err := http.Get("https://raw.githubusercontent.com/gopherjs/gopherjs/master/README.md")
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		return err
-	}
+func t(text string) *template.Template {
+	return template.Must(template.New("").Parse(text))
+}
 
-	var buf bytes.Buffer
-	io.WriteString(&buf, `---
+// Filename -> Template.
+var templates = map[string]*template.Template{
+
+	"index.md": t(`---
 # generated by generate.go; DO NOT EDIT
 layout: index
 title: Home
 permalink: /
 ---
 
-`)
-	_, err = buf.Write(body)
+{{.HTTPGet "https://raw.githubusercontent.com/gopherjs/gopherjs/master/README.md"}}`),
+}
+
+type data struct{}
+
+// HTTPGet fetches the contents at the given url.
+func (data) HTTPGet(url string) (string, error) {
+	resp, err := http.Get(url)
 	if err != nil {
-		return err
+		return "", err
 	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	return string(body), nil
+}
 
-	ioutil.WriteFile("index.md", buf.Bytes(), 0644)
+func gen() error {
+	for filename, t := range templates {
+		var buf bytes.Buffer
+		err := t.Execute(&buf, data{})
+		if err != nil {
+			return err
+		}
+		fmt.Println("writing", filename)
+		err = ioutil.WriteFile(filename, buf.Bytes(), 0644)
+		if err != nil {
+			return err
+		}
+	}
 
 	return nil
 }
