template.go
func (tmpl *Template) funcMapMaker(req *http.Request, writer http.ResponseWriter) template.FuncMap {
	var funcMap = template.FuncMap{}

	for key, fc := range tmpl.render.funcMaps {
		funcMap[key] = fc
	}

	if tmpl.render.Config.FuncMapMaker != nil {
		for key, fc := range tmpl.render.Config.FuncMapMaker(tmpl.render, req, writer) {
			funcMap[key] = fc
		}
	}

	for key, fc := range tmpl.funcMap {
		funcMap[key] = fc
	}
	return funcMap
}
func (tmpl *Template) funcMapMaker(req *http.Request, writer http.ResponseWriter) template.FuncMap {
	var funcMap = template.FuncMap{}

	for key, fc := range tmpl.render.funcMaps {
		funcMap[key] = fc
	}

	if tmpl.render.Config.FuncMapMaker != nil {
		for key, fc := range tmpl.render.Config.FuncMapMaker(tmpl.render, req, writer) {
			funcMap[key] = fc
		}
	}

	for key, fc := range tmpl.funcMap {
		funcMap[key] = fc
	}
	return funcMap
}
// FuncMap get func maps from tmpl