Merge pull request #14406 from ckeditor/ck/9888-preserving-inline-emp…

…ty-elements

Feature (html-support): Introduced configuration option to allow empty inline elements. Closes #9888.

Other (engine): The `DomConverter` should allow registering custom matchers to detect inline object elements. See #9888.

Other (source-editing): Fixed formatting of `<br>` elements in source editing. Whitespaces before `<br>` element should not be added.

packages/ckeditor5-engine/src/model/documentselection.ts

@@ -1135,8 +1135,10 @@ class LiveSelection extends Selection {
 
 			// ...look for a first character node in that range and take attributes from it.
 			for ( const value of range ) {
-				// If the item is an object, we don't want to get attributes from its children.
+				// If the item is an object, we don't want to get attributes from its children...
 				if ( value.item.is( 'element' ) && schema.isObject( value.item ) ) {
+					// ...but collect attributes from inline object.
+					attrs = getTextAttributes( value.item, schema );
 					break;
 				}
 
@@ -1237,7 +1239,10 @@ function getTextAttributes( node: Item | null, schema: Schema ): Iterable<[strin
 
 	// Collect all attributes that can be applied to the text node.
 	for ( const [ key, value ] of node.getAttributes() ) {
-		if ( schema.checkAttribute( '$text', key ) ) {
+		if (
+			schema.checkAttribute( '$text', key ) &&
+			schema.getAttributeProperties( key ).copyFromObject !== false
+		) {
 			attributes.push( [ key, value ] );
 		}
 	}

packages/ckeditor5-engine/src/model/schema.ts

@@ -1764,6 +1764,18 @@ export interface AttributeProperties {
 	 */
 	copyOnEnter?: boolean;
 
+	/**
+	 * Indicates that given attribute should be preserved while replacing the element.
+	 */
+	copyOnReplace?: boolean;
+
+	/**
+	 * Indicates that given text attribute should be copied from an inline object to the next inserted inline content.
+	 *
+	 * @default true
+	 */
+	copyFromObject?: boolean;
+
 	[ name: string ]: unknown;
 }