// FailureReason makes CSRF validation errors available in the request context.
// This is useful when you want to log the cause of the error or report it to
// client.
func FailureReason(r *http.Request) error {
if val, ok := context.GetOk(r, ErrorKey); ok {
if err, ok := val.(error); ok {
return err
}
}
return nil
}
// Token returns a masked CSRF token ready for passing into HTML template or
// a JSON response body. An empty token will be returned if the middleware
// has not been applied (which will fail subsequent validation).
func Token(r *http.Request) string {
if val, ok := context.GetOk(r, TokenKey); ok {
if maskedToken, ok := val.(string); ok {
return maskedToken
}
}
return ""
}
// TemplateField is a template helper for html/template that provides an <input> field
// populated with a CSRF token.
//
// Example:
//
// // The following tag in our form.tmpl template:
// {{ .csrfField }}
//
// // ... becomes:
// <input type="hidden" name="gorilla.csrf.Token" value="<token>">
//
func TemplateField(r *http.Request) template.HTML {
name, ok := context.GetOk(r, FormKey)
if ok {
fragment := fmt.Sprintf(`<input type="hidden" name="%s" value="%s">`,
name, Token(r))
return template.HTML(fragment)
}
return template.HTML("")
}