Add example for usage in Go templates

1 files changed, 34 insertions, 0 deletions

diff --git a/optional/template_test.go b/optional/template_test.go
new file mode 100644
index 0000000..ab4ce76
--- /dev/null
+++ b/optional/template_test.go
@@ -0,0 +1,34 @@
+package optional_test
+
+import (
+	"html/template"
+	"log"
+	"os"
+
+	"xengineering.eu/optional-go/optional"
+)
+
+func ExampleTemplate() {
+	data := struct {
+		Flag optional.Optional[bool]
+	}{
+		Flag: optional.Optional[bool]{
+			Value:  false,
+			Exists: false,
+		},
+	}
+
+	tmpl := `Flag is: {{if .Flag.Exists}}{{.Flag.Value}}{{else}}[none]{{end}}`
+
+	t, err := template.New("optional").Parse(tmpl)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = t.Execute(os.Stdout, data)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Output: Flag is: [none]
+}