added templating structure

ninnemana · ninnemana · commit 920e13d11bca · 2013-09-12T10:52:25.000-05:00
diff --git a/templates.go b/templates.go
@@ -0,0 +1,224 @@
+package web
+
+import (
+	"errors"
+	"html/template"
+	"log"
+	"net/http"
+	"os"
+)
+
+var (
+	tmpl *Template
+)
+
+type Template struct {
+	Layout       string
+	Template     string
+	Bag          map[string]interface{}
+	Writer       http.ResponseWriter
+	FuncMap      template.FuncMap
+	HtmlTemplate *template.Template
+}
+
+/* Templating |-- Using html/template library built into golang http://golang.org/pkg/html/template/ --|
+   ------------------------------ */
+
+func CreateTemplate(w http.ResponseWriter) (templ *Template, err error) {
+	if w == nil {
+		log.Printf("Template Error: %v", err.Error())
+		return
+	}
+	templ = &Template{
+		Writer:  w,
+		Bag:     make(map[string]interface{}),
+		FuncMap: template.FuncMap{},
+	}
+
+	return
+}
+
+func (t Template) SinglePage(file_path string) (err error) {
+
+	dir, err := os.Getwd()
+	if err != nil {
+		return
+	}
+
+	if t.Bag == nil {
+		t.Bag = make(map[string]interface{})
+	}
+	if len(file_path) != 0 {
+		t.Template = dir + "/" + file_path
+	}
+
+	tmpl, err := template.ParseFiles(t.Template)
+	if err != nil {
+		return err
+	}
+	tmpl.Funcs(t.FuncMap)
+	err = tmpl.Execute(t.Writer, t.Bag)
+	if err != nil {
+		log.Println(err)
+	}
+
+	return
+}
+
+func (t Template) DisplayTemplate() (err error) {
+
+	dir, err := os.Getwd()
+	if err != nil {
+		return
+	}
+
+	if t.Layout == "" {
+		t.Layout = "layout.html"
+	}
+	// ensure proper pathing for layout layout files
+	t.Layout = dir + "/" + t.Layout
+	t.Template = dir + "/" + t.Template
+
+	if t.Bag == nil {
+		t.Bag = make(map[string]interface{})
+	}
+
+	templ, err := template.ParseFiles(t.Layout, t.Template)
+	if err != nil {
+		return err
+	}
+	templ.Funcs(t.FuncMap)
+
+	err = templ.Execute(t.Writer, t.Bag)
+	if err != nil {
+		log.Println(err)
+	}
+
+	return
+}
+
+func (t Template) DisplayMultiple(templates []string) (err error) {
+
+	dir, err := os.Getwd()
+	if err != nil {
+		return
+	}
+
+	if t.Layout == "" {
+		t.Layout = "layout.html"
+	}
+	// ensure proper pathing for layout layout files
+	t.Layout = t.Layout
+
+	templ, err := template.ParseFiles(dir + "/" + t.Layout)
+	if err != nil {
+		return err
+	}
+	templ.Funcs(t.FuncMap)
+	for _, filename := range templates {
+		_, err = templ.ParseFiles(dir + "/" + filename)
+	}
+
+	err = templ.Execute(t.Writer, t.Bag)
+	if err != nil {
+		log.Println(err)
+	}
+
+	return
+}
+
+func SetTemplate(t *Template) {
+	tmpl = t
+}
+
+func (t *Template) ParseFile(file string, override bool) error {
+	dir := ""
+	var err error
+	if !override {
+		dir, err = os.Getwd()
+		if err != nil {
+			return err
+		}
+	}
+	var tmpl *template.Template
+	if t.HtmlTemplate == nil {
+
+		tmpl, err = template.New(file).Funcs(t.FuncMap).ParseFiles(dir + "/" + file)
+		if err != nil {
+			return err
+		}
+		tmpl.Funcs(t.FuncMap)
+	} else {
+		// Make sure the FuncMap is added to the template before parsing the new file
+		t.HtmlTemplate.Funcs(t.FuncMap)
+		tmpl, err = t.HtmlTemplate.ParseFiles(dir + "/" + file)
+		if err != nil {
+			return err
+		}
+	}
+	t.HtmlTemplate = tmpl
+
+	if err != nil {
+		log.Println(err)
+	}
+
+	return err
+}
+
+func (t Template) Display(w http.ResponseWriter) error {
+
+	t.Writer = w
+	if t.HtmlTemplate == nil {
+		if t.Template == "" {
+			return errors.New("No template files defined")
+		}
+
+		dir, err := os.Getwd()
+		if err != nil {
+			return err
+		}
+
+		tmpl, err := template.ParseFiles(dir + "/" + t.Template)
+
+		if err != nil {
+			log.Println(err)
+			return err
+		}
+		tmpl.Funcs(t.FuncMap)
+
+		t.HtmlTemplate = tmpl
+		return nil
+	}
+
+	err := tmpl.HtmlTemplate.Execute(t.Writer, t.Bag)
+	if err != nil {
+		log.Println(err)
+	}
+
+	return err
+}
+
+func GetTemplate() (*Template, error) {
+	if tmpl != nil {
+		return tmpl, nil
+	}
+	err := errors.New("No template defined")
+	if err != nil {
+		log.Println(err)
+	}
+
+	return nil, err
+}
+
+func NewTemplate(w http.ResponseWriter) *Template {
+
+	tmpl, err := GetTemplate()
+	if err != nil {
+		tmpl, err = CreateTemplate(w)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return tmpl
+		}
+	}
+	return tmpl
+}
