package atom

import (
	"encoding/xml"
)

type CommonAttributes struct {
	Base                IRI         `xml:"base,attr,omitempty"`
	Lang                LanguageTag `xml:"lang,attr,omitempty"`
	UndefinedAttributes []*xml.Attr `xml:",attr,omitempty"`
}

// NewCommonAttributes creates a new set of CommonAttributes. It returns a
// *CommonAttributes.
func NewCommonAttributes() *CommonAttributes {
	return new(CommonAttributes)
}

// AddExtensionAttribute adds the ExtensionAttribute to the CommonAttributes.
func (c *CommonAttributes) AddExtensionAttribute(name, value string) {
	if c.UndefinedAttributes == nil {
		c.UndefinedAttributes = make([]*xml.Attr, 1)
		c.UndefinedAttributes[0] = &xml.Attr{Name: xml.Name{Local: name}, Value: value}
	} else {
		c.UndefinedAttributes = append(c.UndefinedAttributes, &xml.Attr{Name: xml.Name{Local: name}, Value: value})
	}
}