feat: implement caldav search

vendor/github.com/dolanor/caldav-go/icalendar/values/url.go

@@ -0,0 +1,49 @@
+package values
+
+import (
+	"github.com/dolanor/caldav-go/icalendar/properties"
+	"github.com/dolanor/caldav-go/utils"
+	"net/url"
+)
+
+// a representation of duration for iCalendar
+type Url struct {
+	u url.URL
+}
+
+// encodes the URL into iCalendar format
+func (u *Url) EncodeICalValue() (string, error) {
+	return u.u.String(), nil
+}
+
+// encodes the url params for the iCalendar specification
+func (u *Url) EncodeICalParams() (params properties.Params, err error) {
+	params = properties.Params{
+		properties.ValuePropertyName: "URI",
+	}
+	return
+}
+
+// decodes the URL from iCalendar format
+func (u *Url) DecodeICalValue(value string) error {
+	if parsed, err := url.Parse(value); err != nil {
+		return utils.NewError(u.ValidateICalValue, "unable to parse url", u, err)
+	} else {
+		u.u = *parsed
+		return nil
+	}
+}
+
+// validates the URL for iCalendar format
+func (u *Url) ValidateICalValue() error {
+	if _, err := url.Parse(u.u.String()); err != nil {
+		return utils.NewError(u.ValidateICalValue, "invalid URL object", u, err)
+	} else {
+		return nil
+	}
+}
+
+// creates a new iCalendar duration representation
+func NewUrl(u url.URL) *Url {
+	return &Url{u: u}
+}