Function NewTag

pkg/name/tag.go:77–116

NewTag returns a new Tag representing the given name, according to the given strictness.

(name string, opts ...Option)

// NewTag returns a new Tag representing the given name, according to the given strictness.
func NewTag(name string, opts ...Option) (Tag, error) {
	opt := makeOptions(opts...)
	base := name
	tag := ""

	// Split on ":"
	parts := strings.Split(name, tagDelim)
	// Verify that we aren't confusing a tag for a hostname w/ port for the purposes of weak validation.
	if len(parts) > 1 && !strings.Contains(parts[len(parts)-1], regRepoDelimiter) {
		base = strings.Join(parts[:len(parts)-1], tagDelim)
		tag = parts[len(parts)-1]
		if tag == "" {
			return Tag{}, newErrBadName("%s must specify a tag name after the colon", name)
		}
	}

	// We don't require a tag, but if we get one check it's valid,
	// even when not being strict.
	// If we are being strict, we want to validate the tag regardless in case
	// it's empty.
	if tag != "" || opt.strict {
		if err := checkTag(tag); err != nil {
			return Tag{}, err
		}
	}

	if tag == "" {
		tag = opt.defaultTag
	}

	repo, err := NewRepository(base, opts...)
	if err != nil {
		return Tag{}, err
	}
	return Tag{
		Repository: repo,
		tag:        tag,
		original:   name,
	}, nil
}

// MarshalJSON formats the Tag into a string for JSON serialization.
func (t Tag) MarshalJSON() ([]byte, error) { return json.Marshal(t.String()) }