feat: implement caldav search

vendor/github.com/dolanor/caldav-go/webdav/request.go

@@ -0,0 +1,56 @@
+package webdav
+
+import (
+	"bytes"
+	"encoding/xml"
+	"github.com/dolanor/caldav-go/http"
+	"github.com/dolanor/caldav-go/utils"
+	"io"
+	"io/ioutil"
+	"log"
+	"strings"
+)
+
+var _ = log.Print
+
+// an WebDAV request object
+type Request http.Request
+
+// downcasts the request to the local HTTP interface
+func (r *Request) Http() *http.Request {
+	return (*http.Request)(r)
+}
+
+// creates a new WebDAV request object
+func NewRequest(method string, urlstr string, xmldata ...interface{}) (*Request, error) {
+	if buffer, length, err := xmlToReadCloser(xmldata); err != nil {
+		return nil, utils.NewError(NewRequest, "unable to encode xml data", xmldata, err)
+	} else if r, err := http.NewRequest(method, urlstr, buffer); err != nil {
+		return nil, utils.NewError(NewRequest, "unable to create request", urlstr, err)
+	} else {
+		if buffer != nil {
+			// set the content type to XML if we have a body
+			r.Native().Header.Set("Content-Type", "text/xml; charset=UTF-8")
+			r.ContentLength = int64(length)
+		}
+		return (*Request)(r), nil
+	}
+}
+
+func xmlToReadCloser(xmldata ...interface{}) (io.ReadCloser, int, error) {
+	var buffer []string
+	for _, xmldatum := range xmldata {
+		if encoded, err := xml.Marshal(xmldatum); err != nil {
+			return nil, 0, utils.NewError(xmlToReadCloser, "unable to encode as xml", xmldatum, err)
+		} else {
+			buffer = append(buffer, string(encoded))
+		}
+	}
+	if len(buffer) > 0 {
+		var encoded = strings.Join(buffer, "\n")
+		//		log.Printf("[WebDAV Request]\n%+v\n", encoded)
+		return ioutil.NopCloser(bytes.NewBuffer([]byte(encoded))), len(encoded), nil
+	} else {
+		return nil, 0, nil
+	}
+}