Merge pull request #1 from bhataprameya/Add-non-Array-flattening

flatten only map functionality

README.md

@@ -11,6 +11,7 @@ Flatten is a Go library that simplifies the process of converting arbitrarily ne
 - Support various key styles: dotted, path-like, Rails, or underscores.
 - Define custom key styles to suit your needs.
 - Works with both JSON strings and Go structures.
+- Ability to flatten only maps and not arrays.
 
 ## Installation
 
@@ -81,11 +82,70 @@ flat, err := gojsonflatten.Flatten(nested, "", flatten.RailsStyle, 3)
 // }
 ```
 
+### Flatten Go Maps without Arrays
+
+You can also flatten Go maps while preserving arrays as it is like this::
+
+```GO
+
+import (
+    "github.com/bhataprameya/gojsonflatten"
+)
+
+nested := map[string]interface{}{
+   "a": "b",
+   "c": map[string]interface{}{
+       "d": "e",
+       "f": "g",
+   },
+   "z": []interface{}{"one", "two"},
+}
+
+flat, err := gojsonflatten.FlattenNoArray(nested, "", flatten.RailsStyle, 3)
+
+// Output:
+// {
+//   "a":    "b",
+//   "c[d]": "e",
+//   "c[f]": "g",
+//   "z":    []interface{}{"one", "two"}
+// }
+```
+
+### Flatten JSON Strings without Arrays
+
+You can flatten JSON strings while preserving arrays using FlattenNoArray:
+
+```GO
+import (
+    "github.com/bhataprameya/gojsonflatten"
+)
+
+nested := `{
+  "one": {
+    "two": [
+      "2a",
+      "2b"
+    ]
+  },
+  "side": "value"
+}`
+
+flat, err := gojsonflatten.FlattenStringNoArray(nested, "", flatten.DotStyle, -1)
+
+// Output:
+// {
+//   "one.two": ["2a", "2b"],
+//   "side": "value"
+// }
+
+```
+
 ## Custom Key Style
 
 You can even define a custom key style for flattening:
 
-```go
+```GO
 import (
     "github.com/bhataprameya/gojsonflatten"
 )
@@ -105,7 +165,7 @@ flat, err := gojsonflatten.FlattenString(nested, "", doubleDash, 5)
 
 You can even define a custom key style for flattening:
 
-```go
+```GO
 import (
     "github.com/bhataprameya/gojsonflatten"
 )

flatten.go

@@ -32,23 +32,43 @@ var (
 
 // Flatten generates a flat map from a nested map with a specified depth.
 func Flatten(nested map[string]interface{}, prefix string, style SeparatorStyle, depth int) (map[string]interface{}, error) {
+	return flattenInternal(nested, prefix, style, depth, false)
+}
+
+// FlattenString generates a flat JSON map from a nested JSON string with a specified depth.
+func FlattenString(nestedString, prefix string, style SeparatorStyle, depth int) (string, error) {
+	return flattenStringInternal(nestedString, prefix, style, depth, false)
+}
+
+// FlattenNoArray generates a flat map from a nested map with a specified depth, preserving arrays as strings.
+func FlattenNoArray(nested map[string]interface{}, prefix string, style SeparatorStyle, depth int) (map[string]interface{}, error) {
+	return flattenInternal(nested, prefix, style, depth, true)
+}
+
+// FlattenStringNoArray generates a flat JSON map from a nested JSON string with a specified depth, preserving arrays as strings.
+func FlattenStringNoArray(nestedString, prefix string, style SeparatorStyle, depth int) (string, error) {
+	return flattenStringInternal(nestedString, prefix, style, depth, true)
+}
+
+// flattenInternal generates a flat map from a nested map with a specified depth, optionally preserving arrays as strings.
+func flattenInternal(nested map[string]interface{}, prefix string, style SeparatorStyle, depth int, preserveArray bool) (map[string]interface{}, error) {
 	if depth == 0 {
 		return nested, nil
 	} else if depth > 0 {
 		depth++
 	}
 
 	flatmap := make(map[string]interface{})
-	err := flatten(true, flatmap, nested, prefix, style, depth)
+	err := flatten(true, flatmap, nested, prefix, style, depth, preserveArray)
 	if err != nil {
 		return nil, err
 	}
 
 	return flatmap, nil
 }
 
-// FlattenString generates a flat JSON map from a nested JSON string with a specified depth.
-func FlattenString(nestedString, prefix string, style SeparatorStyle, depth int) (string, error) {
+// flattenStringInternal generates a flat JSON map from a nested JSON string with a specified depth, optionally preserving arrays as strings.
+func flattenStringInternal(nestedString, prefix string, style SeparatorStyle, depth int, preserveArray bool) (string, error) {
 	if !isJsonMap.MatchString(nestedString) {
 		return "", ErrNotValidJsonInput
 	}
@@ -59,7 +79,7 @@ func FlattenString(nestedString, prefix string, style SeparatorStyle, depth int)
 		return "", err
 	}
 
-	flatmap, err := Flatten(nested, prefix, style, depth)
+	flatmap, err := flattenInternal(nested, prefix, style, depth, preserveArray)
 	if err != nil {
 		return "", err
 	}
@@ -73,7 +93,7 @@ func FlattenString(nestedString, prefix string, style SeparatorStyle, depth int)
 }
 
 // flatten recursively processes nested structures and flattens them.
-func flatten(top bool, flatMap map[string]interface{}, nested interface{}, prefix string, style SeparatorStyle, depth int) error {
+func flatten(top bool, flatMap map[string]interface{}, nested interface{}, prefix string, style SeparatorStyle, depth int, keepArrays bool) error {
 	if depth == 0 {
 		// If the desired depth is reached, add the prefix and nested value to the flat map.
 		flatMap[prefix] = nested
@@ -85,7 +105,7 @@ func flatten(top bool, flatMap map[string]interface{}, nested interface{}, prefi
 		switch v.(type) {
 		case map[string]interface{}, []interface{}:
 			// If the value is a nested map or slice, continue flattening recursively.
-			if err := flatten(false, flatMap, v, newKey, style, depth-1); err != nil {
+			if err := flatten(false, flatMap, v, newKey, style, depth-1, keepArrays); err != nil {
 				return err
 			}
 		default:
@@ -104,10 +124,14 @@ func flatten(top bool, flatMap map[string]interface{}, nested interface{}, prefi
 			assign(newKey, v)
 		}
 	case []interface{}:
-		for i, v := range nested {
-			newKey := enkey(top, prefix, strconv.Itoa(i), style)
-			// Process and assign the index-value pair.
-			assign(newKey, v)
+		if !keepArrays {
+			for i, v := range nested {
+				newKey := enkey(top, prefix, strconv.Itoa(i), style)
+				// Process and assign the index-value pair.
+				assign(newKey, v)
+			}
+		} else {
+			flatMap[prefix] = nested
 		}
 	default:
 		return ErrNotValidInput