Media Utils: Restrict file uploads with multiple prop in uploadMedia and mediaUpload

packages/block-editor/src/components/background-image-control/index.js

@@ -313,19 +313,14 @@ function BackgroundImageControls( {
 
 	// Drag and drop callback, restricting image to one.
 	const onFilesDrop = ( filesList ) => {
-		if ( filesList?.length > 1 ) {
-			onUploadError(
-				__( 'Only one image can be used as a background image.' )
-			);
-			return;
-		}
 		getSettings().mediaUpload( {
 			allowedTypes: [ IMAGE_BACKGROUND_TYPE ],
 			filesList,
 			onFileChange( [ image ] ) {
 				onSelectMedia( image );
 			},
 			onError: onUploadError,
+			multiple: false,
 		} );
 	};
 

packages/block-editor/src/components/media-placeholder/index.js

@@ -227,6 +227,7 @@ export function MediaPlaceholder( {
 			filesList: files,
 			onFileChange: setMedia,
 			onError,
+			multiple,
 		} );
 	};
 

packages/block-library/src/site-logo/edit.js

@@ -499,11 +499,6 @@ export default function LogoEdit( {
 	};
 
 	const onFilesDrop = ( filesList ) => {
-		if ( filesList?.length > 1 ) {
-			onUploadError( __( 'Only one image can be used as a site logo.' ) );
-			return;
-		}
-
 		getSettings().mediaUpload( {
 			allowedTypes: ALLOWED_MEDIA_TYPES,
 			filesList,
@@ -515,6 +510,7 @@ export default function LogoEdit( {
 				onInitialSelectLogo( image );
 			},
 			onError: onUploadError,
+			multiple: false,
 		} );
 	};
 

packages/editor/README.md

@@ -500,6 +500,7 @@ _Parameters_
 -   _$0.onError_ `Function`: Function called when an error happens.
 -   _$0.onFileChange_ `Function`: Function called each time a file or a temporary representation of the file is available.
 -   _$0.onSuccess_ `Function`: Function called after the final representation of the file is available.
+-   _$0.multiple_ `boolean`: Whether to allow multiple files to be uploaded.
 
 ### MediaUploadCheck
 

packages/editor/src/components/post-featured-image/index.js

@@ -125,6 +125,7 @@ function PostFeaturedImage( {
 				noticeOperations.removeAllNotices();
 				noticeOperations.createErrorNotice( message );
 			},
+			multiple: false,
 		} );
 	}
 
@@ -345,6 +346,7 @@ const applyWithDispatch = withDispatch(
 							noticeOperations.removeAllNotices();
 							noticeOperations.createErrorNotice( message );
 						},
+						multiple: false,
 					} );
 			},
 			onRemoveImage() {

packages/editor/src/utils/media-upload/index.js

@@ -28,6 +28,7 @@ const noop = () => {};
  * @param {Function} $0.onError           Function called when an error happens.
  * @param {Function} $0.onFileChange      Function called each time a file or a temporary representation of the file is available.
  * @param {Function} $0.onSuccess         Function called after the final representation of the file is available.
+ * @param {boolean}  $0.multiple          Whether to allow multiple files to be uploaded.
  */
 export default function mediaUpload( {
 	additionalData = {},
@@ -37,6 +38,7 @@ export default function mediaUpload( {
 	onError = noop,
 	onFileChange,
 	onSuccess,
+	multiple = true,
 } ) {
 	const { getCurrentPost, getEditorSettings } = select( editorStore );
 	const {
@@ -92,5 +94,6 @@ export default function mediaUpload( {
 			onError( message );
 		},
 		wpAllowedMimeTypes,
+		multiple,
 	} );
 }

packages/media-utils/README.md

@@ -56,6 +56,7 @@ _Parameters_
 -   _$0.onFileChange_ `UploadMediaArgs[ 'onFileChange' ]`: Function called each time a file or a temporary representation of the file is available.
 -   _$0.wpAllowedMimeTypes_ `UploadMediaArgs[ 'wpAllowedMimeTypes' ]`: List of allowed mime types and file extensions.
 -   _$0.signal_ `UploadMediaArgs[ 'signal' ]`: Abort signal.
+-   _$0.multiple_ `UploadMediaArgs[ 'multiple' ]`: Whether to allow multiple files to be uploaded.
 
 ### validateFileSize
 

packages/media-utils/src/utils/upload-error.ts

@@ -1,7 +1,7 @@
 interface UploadErrorArgs {
 	code: string;
 	message: string;
-	file: File;
+	file?: File;
 	cause?: Error;
 }
 
@@ -13,7 +13,7 @@ interface UploadErrorArgs {
  */
 export class UploadError extends Error {
 	code: string;
-	file: File;
+	file?: File;
 
 	constructor( { code, message, file, cause }: UploadErrorArgs ) {
 		super( message, { cause } );

packages/media-utils/src/utils/upload-media.ts

@@ -42,6 +42,8 @@ interface UploadMediaArgs {
 	wpAllowedMimeTypes?: Record< string, string > | null;
 	// Abort signal.
 	signal?: AbortSignal;
+	// Whether to allow multiple files to be uploaded.
+	multiple?: boolean;
 }
 
 /**
@@ -57,6 +59,7 @@ interface UploadMediaArgs {
  * @param $0.onFileChange       Function called each time a file or a temporary representation of the file is available.
  * @param $0.wpAllowedMimeTypes List of allowed mime types and file extensions.
  * @param $0.signal             Abort signal.
+ * @param $0.multiple           Whether to allow multiple files to be uploaded.
  */
 export function uploadMedia( {
 	wpAllowedMimeTypes,
@@ -67,7 +70,18 @@ export function uploadMedia( {
 	onError,
 	onFileChange,
 	signal,
+	multiple = true,
 }: UploadMediaArgs ) {
+	if ( ! multiple && filesList.length > 1 ) {
+		onError?.(
+			new UploadError( {
+				code: 'GENERAL',
+				message: __( 'Only one file can be used here.' ),
+			} )
+		);
+		return;
+	}
+
 	const validFiles = [];
 
 	const filesSet: Array< Partial< Attachment > | null > = [];