Changed metadata variables type:

from map[string]interface{} to map[string]string

middleware/markdown/metadata.go

@@ -13,9 +13,9 @@ import (
 
 var (
 	parsers = []MetadataParser{
-		&JSONMetadataParser{metadata: Metadata{Variables: make(map[string]interface{})}},
-		&TOMLMetadataParser{metadata: Metadata{Variables: make(map[string]interface{})}},
-		&YAMLMetadataParser{metadata: Metadata{Variables: make(map[string]interface{})}},
+		&JSONMetadataParser{metadata: Metadata{Variables: make(map[string]string)}},
+		&TOMLMetadataParser{metadata: Metadata{Variables: make(map[string]string)}},
+		&YAMLMetadataParser{metadata: Metadata{Variables: make(map[string]string)}},
 	}
 )
 
@@ -28,7 +28,7 @@ type Metadata struct {
 	Template string
 
 	// Variables to be used with Template
-	Variables map[string]interface{}
+	Variables map[string]string
 }
 
 // load loads parsed values in parsedMap into Metadata
@@ -40,7 +40,7 @@ func (m *Metadata) load(parsedMap map[string]interface{}) {
 		m.Template, _ = template.(string)
 	}
 	if variables, ok := parsedMap["variables"]; ok {
-		m.Variables, _ = variables.(map[string]interface{})
+		m.Variables, _ = variables.(map[string]string)
 	}
 }
 
@@ -76,6 +76,15 @@ func (j *JSONMetadataParser) Parse(b []byte) ([]byte, error) {
 	if err := decoder.Decode(&m); err != nil {
 		return b, err
 	}
+	if vars, ok := m["variables"].(map[string]interface{}); ok {
+		vars1 := make(map[string]string)
+		for k, v := range vars {
+			if val, ok := v.(string); ok {
+				vars1[k] = val
+			}
+		}
+		m["variables"] = vars1
+	}
 
 	j.metadata.load(m)
 
@@ -120,6 +129,15 @@ func (t *TOMLMetadataParser) Parse(b []byte) ([]byte, error) {
 	if err := toml.Unmarshal(b, &m); err != nil {
 		return markdown, err
 	}
+	if vars, ok := m["variables"].(map[string]interface{}); ok {
+		vars1 := make(map[string]string)
+		for k, v := range vars {
+			if val, ok := v.(string); ok {
+				vars1[k] = val
+			}
+		}
+		m["variables"] = vars1
+	}
 	t.metadata.load(m)
 	return markdown, nil
 }
@@ -160,10 +178,12 @@ func (y *YAMLMetadataParser) Parse(b []byte) ([]byte, error) {
 	// convert variables (if present) to map[string]interface{}
 	// to match expected type
 	if vars, ok := m["variables"].(map[interface{}]interface{}); ok {
-		vars1 := make(map[string]interface{})
+		vars1 := make(map[string]string)
 		for k, v := range vars {
 			if key, ok := k.(string); ok {
-				vars1[key] = v
+				if val, ok := v.(string); ok {
+					vars1[key] = val
+				}
 			}
 		}
 		m["variables"] = vars1

middleware/markdown/metadata_test.go

@@ -98,7 +98,7 @@ func TestParsers(t *testing.T) {
 	expected := Metadata{
 		Title:     "A title",
 		Template:  "default",
-		Variables: map[string]interface{}{"name": "value"},
+		Variables: map[string]string{"name": "value"},
 	}
 	compare := func(m Metadata) bool {
 		if m.Title != expected.Title {

middleware/markdown/process.go

@@ -20,13 +20,13 @@ const (
 
 type MarkdownData struct {
 	middleware.Context
-	Doc map[string]interface{}
+	Doc map[string]string
 }
 
 // Process processes the contents of a page in b. It parses the metadata
 // (if any) and uses the template (if found).
 func (md Markdown) Process(c Config, requestPath string, b []byte, ctx middleware.Context) ([]byte, error) {
-	var metadata = Metadata{Variables: make(map[string]interface{})}
+	var metadata = Metadata{Variables: make(map[string]string)}
 	var markdown []byte
 	var err error
 
@@ -166,7 +166,7 @@ func defaultTemplate(c Config, metadata Metadata, requestPath string) []byte {
 	}
 
 	// Title is first line (length-limited), otherwise filename
-	title, _ := metadata.Variables["title"].(string)
+	title, _ := metadata.Variables["title"]
 
 	html := []byte(htmlTemplate)
 	html = bytes.Replace(html, []byte("{{title}}"), []byte(title), 1)