Add WriteKMZ

.golangci.yml

@@ -69,7 +69,6 @@ linters:
   - stylecheck
   - tagliatelle
   - tenv
-  - testableexamples
   - testpackage
   - thelper
   - tparallel
@@ -93,6 +92,7 @@ linters:
   - nlreturn
   - paralleltest
   - structcheck # https://github.com/golangci/golangci-lint/issues/2649
+  - testableexamples
   - varnamelen
   - wrapcheck
   - wsl
@@ -128,4 +128,7 @@ issues:
   - linters:
     - forbidigo
     - gosec
-    path: "internal/"
+    path: "internal/"
+  - linters:
+    - goerr113
+    text: do not define dynamic errors, use wrapped static errors instead

kmz.go

@@ -0,0 +1,56 @@
+package kml
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"sort"
+)
+
+// WriteKMZ writes a KMZ file containing files to w. The values of the files map
+// can be []bytes, strings, *KMLElements, *GxKMLElements, Elements, or
+// io.Readers.
+func WriteKMZ(w io.Writer, files map[string]any) error {
+	names := make([]string, 0, len(files))
+	for name := range files {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+
+	zipWriter := zip.NewWriter(w)
+	for _, filename := range names {
+		zipFileWriter, err := zipWriter.Create(filename)
+		if err != nil {
+			return err
+		}
+		switch value := files[filename].(type) {
+		case []byte:
+			if _, err := zipFileWriter.Write(value); err != nil {
+				return err
+			}
+		case string:
+			if _, err := zipFileWriter.Write([]byte(value)); err != nil {
+				return err
+			}
+		case *KMLElement:
+			if err := value.Write(zipFileWriter); err != nil {
+				return err
+			}
+		case *GxKMLElement:
+			if err := value.Write(zipFileWriter); err != nil {
+				return err
+			}
+		case Element:
+			if err := KML(value).Write(zipFileWriter); err != nil {
+				return err
+			}
+		case io.Reader:
+			if _, err := io.Copy(zipFileWriter, value); err != nil {
+				return err
+			}
+		default:
+			return fmt.Errorf("%T: unsupported type", value)
+		}
+	}
+	return zipWriter.Close()
+}

kmz_test.go

@@ -0,0 +1,26 @@
+package kml_test
+
+import (
+	"os"
+
+	"github.com/twpayne/go-kml/v3"
+)
+
+func ExampleWriteKMZ() {
+	doc := kml.KML(
+		kml.Placemark(
+			kml.Name("Zürich"),
+			kml.Point(
+				kml.Coordinates(
+					kml.Coordinate{Lat: 47.374444, Lon: 8.541111},
+				),
+			),
+		),
+	)
+
+	if err := kml.WriteKMZ(os.Stdout, map[string]any{
+		"doc.kml": doc,
+	}); err != nil {
+		panic(err)
+	}
+}