Block Editor: Abstract selection position retrieval

packages/block-editor/README.md

@@ -562,6 +562,18 @@ _Related_
 
 -   <https://github.com/WordPress/gutenberg/blob/HEAD/packages/block-editor/src/components/plain-text/README.md>
 
+### retrieveSelectedAttribute
+
+Retrieve the block attribute that contains the selection position.
+
+_Parameters_
+
+-   _blockAttributes_ `Object`: Block attributes.
+
+_Returns_
+
+-   `string`: The name of the block attribute that was previously selected.
+
 ### RichText
 
 _Related_
@@ -613,6 +625,12 @@ _Related_
 
 -   <https://github.com/WordPress/gutenberg/blob/HEAD/packages/block-editor/src/components/skip-to-selected-block/README.md>
 
+### START_OF_SELECTED_AREA
+
+A robust way to retain selection position through various
+transforms is to insert a special character at the position and
+then recover it.
+
 ### store
 
 Store definition for the block editor namespace.

packages/block-editor/src/components/rich-text/use-input-rules.js

@@ -1,8 +1,3 @@
-/**
- * External dependencies
- */
-import { findKey } from 'lodash';
-
 /**
  * WordPress dependencies
  */
@@ -17,21 +12,14 @@ import { useDispatch } from '@wordpress/data';
  */
 import { store as blockEditorStore } from '../../store';
 import { preventEventDiscovery } from './prevent-event-discovery';
-
-// A robust way to retain selection position through various
-// transforms is to insert a special character at the position and
-// then recover it.
-const START_OF_SELECTED_AREA = '\u0086';
+import { retrieveSelectedAttribute, START_OF_SELECTED_AREA } from '../../utils';
 
 function findSelection( blocks ) {
 	let i = blocks.length;
 
 	while ( i-- ) {
-		const attributeKey = findKey(
-			blocks[ i ].attributes,
-			( v ) =>
-				typeof v === 'string' &&
-				v.indexOf( START_OF_SELECTED_AREA ) !== -1
+		const attributeKey = retrieveSelectedAttribute(
+			blocks[ i ].attributes
 		);
 
 		if ( attributeKey ) {

packages/block-editor/src/store/actions.js

@@ -1,7 +1,7 @@
 /**
  * External dependencies
  */
-import { castArray, findKey, first, isObject, last, some } from 'lodash';
+import { castArray, first, isObject, last, some } from 'lodash';
 
 /**
  * WordPress dependencies
@@ -26,6 +26,7 @@ import deprecated from '@wordpress/deprecated';
  * Internal dependencies
  */
 import { mapRichTextSettings } from './utils';
+import { retrieveSelectedAttribute, START_OF_SELECTED_AREA } from '../utils';
 
 /**
  * Action which will insert a default block insert action if there
@@ -771,10 +772,6 @@ export const __unstableDeleteSelection =
 			...mapRichTextSettings( attributeDefinitionB ),
 		} );
 
-		// A robust way to retain selection position through various transforms
-		// is to insert a special character at the position and then recover it.
-		const START_OF_SELECTED_AREA = '\u0086';
-
 		valueA = remove( valueA, selectionA.offset, valueA.text.length );
 		valueB = insert( valueB, START_OF_SELECTED_AREA, 0, selectionB.offset );
 
@@ -822,12 +819,7 @@ export const __unstableDeleteSelection =
 			);
 		}
 
-		const newAttributeKey = findKey(
-			updatedAttributes,
-			( v ) =>
-				typeof v === 'string' &&
-				v.indexOf( START_OF_SELECTED_AREA ) !== -1
-		);
+		const newAttributeKey = retrieveSelectedAttribute( updatedAttributes );
 
 		const convertedHtml = updatedAttributes[ newAttributeKey ];
 		const convertedValue = create( {
@@ -1052,10 +1044,6 @@ export const mergeBlocks =
 			}
 		}
 
-		// A robust way to retain selection position through various transforms
-		// is to insert a special character at the position and then recover it.
-		const START_OF_SELECTED_AREA = '\u0086';
-
 		// Clone the blocks so we don't insert the character in a "live" block.
 		const cloneA = cloneBlock( blockA );
 		const cloneB = cloneBlock( blockB );
@@ -1098,12 +1086,8 @@ export const mergeBlocks =
 		);
 
 		if ( canRestoreTextSelection ) {
-			const newAttributeKey = findKey(
-				updatedAttributes,
-				( v ) =>
-					typeof v === 'string' &&
-					v.indexOf( START_OF_SELECTED_AREA ) !== -1
-			);
+			const newAttributeKey =
+				retrieveSelectedAttribute( updatedAttributes );
 			const convertedHtml = updatedAttributes[ newAttributeKey ];
 			const convertedValue = create( {
 				html: convertedHtml,

packages/block-editor/src/utils/index.js

@@ -1,3 +1,4 @@
 export { default as transformStyles } from './transform-styles';
 export * from './block-variation-transforms';
 export { default as getPxFromCssUnit } from './parse-css-unit-to-px';
+export * from './selection';

packages/block-editor/src/utils/selection.js

@@ -0,0 +1,25 @@
+/**
+ * External dependencies
+ */
+import { findKey } from 'lodash';
+
+/**
+ * A robust way to retain selection position through various
+ * transforms is to insert a special character at the position and
+ * then recover it.
+ */
+export const START_OF_SELECTED_AREA = '\u0086';
+
+/**
+ * Retrieve the block attribute that contains the selection position.
+ *
+ * @param {Object} blockAttributes Block attributes.
+ * @return {string} The name of the block attribute that was previously selected.
+ */
+export function retrieveSelectedAttribute( blockAttributes ) {
+	return findKey(
+		blockAttributes,
+		( v ) =>
+			typeof v === 'string' && v.indexOf( START_OF_SELECTED_AREA ) !== -1
+	);
+}