Move array transforms to internal header pending backend support. (#1139)

1 files changed, 28 insertions, 0 deletions

diff --git a/Firestore/Source/API/FIRFieldValue+Internal.h b/Firestore/Source/API/FIRFieldValue+Internal.h
index 1618cd4..883a307 100644
--- a/Firestore/Source/API/FIRFieldValue+Internal.h
+++ b/Firestore/Source/API/FIRFieldValue+Internal.h
@@ -54,4 +54,32 @@ NS_ASSUME_NONNULL_BEGIN
 @property(strong, nonatomic, readonly) NSArray<id> *elements;
 @end
 
+// TODO(array-features): Move to FIRFieldValue.h once backend support lands.
+@interface FIRFieldValue ()
+
+/**
+ * Returns a special value that can be used with setData() or updateData() that tells the server to
+ * union the given elements with any array value that already exists on the server. Each
+ * specified element that doesn't already exist in the array will be added to the end. If the
+ * field being modified is not already an array it will be overwritten with an array containing
+ * exactly the specified elements.
+ *
+ * @param elements The elements to union into the array.
+ * @return The FieldValue sentinel for use in a call to setData() or updateData().
+ */
++ (instancetype)fieldValueForArrayUnion:(NSArray<id> *)elements NS_SWIFT_NAME(arrayUnion(_:));
+
+/**
+ * Returns a special value that can be used with setData() or updateData() that tells the server to
+ * remove the given elements from any array value that already exists on the server. All
+ * instances of each element specified will be removed from the array. If the field being
+ * modified is not already an array it will be overwritten with an empty array.
+ *
+ * @param elements The elements to remove from the array.
+ * @return The FieldValue sentinel for use in a call to setData() or updateData().
+ */
++ (instancetype)fieldValueForArrayRemove:(NSArray<id> *)elements NS_SWIFT_NAME(arrayRemove(_:));
+
+@end
+
 NS_ASSUME_NONNULL_END