more updates and renaming

Former-commit-id: 8c194821906b2170df92672fe9dfb9d710640659

page/functions.go

@@ -0,0 +1,47 @@
+package page
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"html/template"
+	"log"
+	"reflect"
+)
+
+// Create the functions map, then the template, check for erros and
+// execute the template if there aren't errors
+var functionMap = template.FuncMap{
+	"Defined":      defined,
+	"CSS":          css,
+	"Marshal":      marshal,
+	"EncodeBase64": encodeBase64,
+}
+
+// defined checks if variable is defined in a struct
+func defined(data interface{}, field string) bool {
+	t := reflect.Indirect(reflect.ValueOf(data)).Type()
+
+	if t.Kind() != reflect.Struct {
+		log.Print("Non-struct type not allowed.")
+		return false
+	}
+
+	_, b := t.FieldByName(field)
+	return b
+}
+
+// css returns the sanitized and safe css
+func css(s string) template.CSS {
+	return template.CSS(s)
+}
+
+// marshal converts an interface to json and sanitizes it
+func marshal(v interface{}) template.JS {
+	a, _ := json.Marshal(v)
+	return template.JS(a)
+}
+
+// encodeBase64 encodes a string in base 64
+func encodeBase64(s string) string {
+	return base64.StdEncoding.EncodeToString([]byte(s))
+}