json and dump filter

config/tree.go

@@ -1,11 +1,56 @@
 package config
 
 import (
+	"fmt"
 	"reflect"
 
 	"github.com/imdario/mergo"
 )
 
+// MapString is a map[string]interface{} which always unmarsahls yaml to map[string]interface{}
+type MapString map[string]interface{}
+
+// UnmarshalYAML handles all maps as map[string]interface{} for later JSON
+// see https://github.com/elastic/beats/blob/6435194af9f42cbf778ca0a1a92276caf41a0da8/libbeat/common/mapstr.go
+func (ms *MapString) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var result map[interface{}]interface{}
+	err := unmarshal(&result)
+	if err != nil {
+		return err
+	}
+	*ms = cleanUpInterfaceMap(result)
+	return nil
+}
+
+func cleanUpInterfaceArray(in []interface{}) []interface{} {
+	result := make([]interface{}, len(in))
+	for i, v := range in {
+		result[i] = cleanUpMapValue(v)
+	}
+	return result
+}
+
+func cleanUpInterfaceMap(in map[interface{}]interface{}) MapString {
+	result := make(MapString)
+	for k, v := range in {
+		result[fmt.Sprintf("%v", k)] = cleanUpMapValue(v)
+	}
+	return result
+}
+
+func cleanUpMapValue(v interface{}) interface{} {
+	switch v := v.(type) {
+	case []interface{}:
+		return cleanUpInterfaceArray(v)
+	case map[interface{}]interface{}:
+		return cleanUpInterfaceMap(v)
+	case string:
+		return v
+	default:
+		return fmt.Sprintf("%v", v)
+	}
+}
+
 // CollectionConfig describes a collection
 type CollectionConfig struct {
 	Name        *string `yaml:"Name"`
@@ -26,7 +71,7 @@ type ThisPathConfig struct {
 	Navname     *string             `yaml:"Navname"`
 	GoTo        *string             `yaml:"GoTo"`
 	Collections []*CollectionConfig `yaml:"Collections"`
-	Data        interface{}         `yaml:"Data"`
+	Data        MapString           `yaml:"Data"`
 }
 
 // IndexConfig describes index input and output file
@@ -85,7 +130,7 @@ type PathConfig struct {
 	Markdown *MarkdownConfig `yaml:"Markdown"`
 	Imaging  *ImagingConfig  `yaml:"Imaging"`
 
-	Data map[string]interface{} `yaml:"Data"`
+	Data MapString `yaml:"Data"`
 }
 
 // PathConfigTree is complete config tree of content dir
@@ -94,7 +139,7 @@ type PathConfigTree struct {
 	OutputPath string
 	Hidden     bool // for collections which are not part of the navigation
 
-	ColMap map[string]interface{}
+	ColMap MapString
 
 	InputFiles []string
 	OtherFiles []string