Add transform to get a field value from two different paths. closes #55

plugin/transform/primitives.go

@@ -26,6 +26,7 @@ import (
 // return a field value of either the hydrate call result (if present)  or the root item if not
 // the field name is in the 'Param'
 func FieldValue(_ context.Context, d *TransformData) (interface{}, error) {
+
 	var item = d.HydrateItem
 
 	propertyPath, ok := d.Param.(string)
@@ -41,6 +42,33 @@ func FieldValue(_ context.Context, d *TransformData) (interface{}, error) {
 	return fieldValue, nil
 }
 
+func FieldsValue(_ context.Context, d *TransformData) (interface{}, error) {
+	var item = d.HydrateItem
+
+	propertyPath, ok := d.Param.([]string)
+
+	if !ok {
+		return nil, fmt.Errorf("'FieldValue' requires a string parameter containing property path but received %v", d.Param)
+	}
+
+	for _, value := range propertyPath {
+		hydrateItem := reflect.ValueOf(item)
+		if hydrateItem.Type().Kind() != reflect.Ptr {
+			hydrateItem = reflect.New(reflect.TypeOf(item))
+		}
+		property := hydrateItem.Elem().FieldByName(value)
+		if property.IsValid() {
+			fieldValue, ok := helpers.GetNestedFieldValueFromInterface(item, value)
+			if !ok {
+				log.Printf("[TRACE] failed to retrieve property path %s\n", value)
+			}
+			return fieldValue, nil
+		}
+
+	}
+	return nil, nil
+}
+
 // FieldValueCamelCase :: intended for the start of a transform chain
 // convert the column name to camel case and call FieldValue
 func FieldValueCamelCase(ctx context.Context, d *TransformData) (interface{}, error) {

plugin/transform/primitives_test.go

@@ -578,6 +578,30 @@ Statement:
 		function: FieldValueTag,
 		expected: "ERROR",
 	},
+	"FieldsValue string first value": {
+		d: &TransformData{
+			HydrateItem: taggedStructInstance,
+			Param:       []string{"GitURL", "GetColumn"},
+		},
+		function: FieldsValue,
+		expected: taggedStructInstance.GitURL,
+	},
+	"FieldsValue string second value": {
+		d: &TransformData{
+			HydrateItem: taggedStructInstance,
+			Param:       []string{"GetColumn", "NodeID"},
+		},
+		function: FieldsValue,
+		expected: taggedStructInstance.NodeID,
+	},
+	"FieldsValue Invalid Value": {
+		d: &TransformData{
+			HydrateItem: taggedStructInstance,
+			Param:       []string{"GetColumn", "ListColumn"},
+		},
+		function: FieldsValue,
+		expected: nil,
+	},
 	"UnixToTimestamp time conversion int64": {
 		d: &TransformData{
 			Value: 1611061921,

plugin/transform/transform.go

@@ -20,6 +20,10 @@ func FromField(field string) *ColumnTransforms {
 	return &ColumnTransforms{Transforms: []*TransformCall{{Transform: FieldValue, Param: field}}}
 }
 
+func FromFields(fields []string) *ColumnTransforms {
+	return &ColumnTransforms{Transforms: []*TransformCall{{Transform: FieldsValue, Param: fields}}}
+}
+
 // Generate a value by returning the raw hydrate item
 func FromValue() *ColumnTransforms {
 	return &ColumnTransforms{Transforms: []*TransformCall{{Transform: RawValue}}}