feat: parse template meta

go.mod

@@ -1,3 +1,5 @@
 module github.com/lancatlin/mdsh-go
 
 go 1.24.5
+
+require gopkg.in/yaml.v3 v3.0.1 // indirect

go.sum

@@ -0,0 +1,3 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -10,7 +10,12 @@ import (
 
 var tmpl = `
 ---
-title: This is the title
+output: "reports/${from}.md"
+params:
+  from:
+    required: true
+  file:
+    default: "ledger.j"
 ---
 Hello this is the text:
 {{ sh "hledger bal assets" }}
@@ -50,7 +55,11 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	fmt.Printf("'%s'", frontmatter)
+	templateMeta, err := parseFrontmatter(frontmatter)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("'%s'", templateMeta)
 	t, err := template.New("foo").Funcs(funcMap).Parse(body)
 	if err != nil {
 		panic(err)

parse.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"fmt"
+
+	"gopkg.in/yaml.v3"
+)
+
+func parseFrontmatter(input string) (meta TemplateMeta, err error) {
+	err = yaml.Unmarshal([]byte(input), &meta)
+	if err != nil {
+		err = fmt.Errorf("Failed to parse frontmatter: %w", err)
+		return
+	}
+	return
+}

types.go

@@ -0,0 +1,21 @@
+package main
+
+import "encoding/json"
+
+type TemplateMeta struct {
+	Output string               `yaml:"output"`
+	Params map[string]ParamSpec `yaml:"params"`
+}
+
+func (meta TemplateMeta) String() string {
+	data, err := json.Marshal(meta)
+	if err != nil {
+		panic(err)
+	}
+	return string(data)
+}
+
+type ParamSpec struct {
+	Required bool   `yaml:"required"`
+	Default  string `yaml:"default"`
+}