adding item.Omittable interface for field-level omission of data in responses, implementation in handler and separating source into individual files for other interface impls

1 files changed, 34 insertions, 0 deletions

diff --git a/system/api/omit.go b/system/api/omit.go
new file mode 100644
index 0000000..46e172c
--- /dev/null
+++ b/system/api/omit.go
@@ -0,0 +1,34 @@
+package api
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/ponzu-cms/ponzu/system/item"
+
+	"github.com/tidwall/sjson"
+)
+
+func omit(it interface{}, res http.ResponseWriter, req *http.Request, data *[]byte) ([]byte, error) {
+	// is it Omittable
+	om, ok := it.(item.Omittable)
+	if !ok {
+		return *data, nil
+	}
+
+	// get fields to omit from json data
+	fields := om.Omit()
+
+	// remove each field from json, all responses contain json object(s) in top-level "data" array
+	var omitted []byte
+	for i := range fields {
+		var err error
+		omitted, err = sjson.DeleteBytes(*data, "data."+fields[i])
+		if err != nil {
+			log.Println("Erorr omitting field:", fields[i], "from item.Omittable:", it)
+			return nil, err
+		}
+	}
+
+	return omitted, nil
+}