docs: example for getSelectedBlock (WordPress#66108)

* add: example for getSelectedBlock

* change: build docs

docs/reference-guides/data/data-core-block-editor.md

@@ -738,6 +738,39 @@ _Returns_
 
 Returns the currently selected block, or null if there is no selected block.
 
+_Usage_
+
+```js
+import { select } from '@wordpress/data';
+import { store as blockEditorStore } from '@wordpress/block-editor';
+
+// Set initial active block client ID
+let activeBlockClientId = null;
+
+const getActiveBlockData = () => {
+	const activeBlock = select( blockEditorStore ).getSelectedBlock();
+
+	if ( activeBlock && activeBlock.clientId !== activeBlockClientId ) {
+		activeBlockClientId = activeBlock.clientId;
+
+		// Get active block name and attributes
+		const activeBlockName = activeBlock.name;
+		const activeBlockAttributes = activeBlock.attributes;
+
+		// Log active block name and attributes
+		console.log( activeBlockName, activeBlockAttributes );
+	}
+};
+
+// Subscribe to changes in the editor
+// wp.data.subscribe(() => {
+// getActiveBlockData()
+// })
+
+// Update active block data on click
+// onclick="getActiveBlockData()"
+```
+
 _Parameters_
 
 -   _state_ `Object`: Global application state.

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

@@ -542,6 +542,39 @@ export function getSelectedBlockClientId( state ) {
  *
  * @param {Object} state Global application state.
  *
+ * @example
+ *
+ *```js
+ * import { select } from '@wordpress/data'
+ * import { store as blockEditorStore } from '@wordpress/block-editor'
+ *
+ * // Set initial active block client ID
+ * let activeBlockClientId = null
+ *
+ * const getActiveBlockData = () => {
+ * 	const activeBlock = select(blockEditorStore).getSelectedBlock()
+ *
+ * 	if (activeBlock && activeBlock.clientId !== activeBlockClientId) {
+ * 		activeBlockClientId = activeBlock.clientId
+ *
+ * 		// Get active block name and attributes
+ * 		const activeBlockName = activeBlock.name
+ * 		const activeBlockAttributes = activeBlock.attributes
+ *
+ * 		// Log active block name and attributes
+ * 		console.log(activeBlockName, activeBlockAttributes)
+ * 		}
+ * 	}
+ *
+ * 	// Subscribe to changes in the editor
+ * 	// wp.data.subscribe(() => {
+ * 		// getActiveBlockData()
+ * 	// })
+ *
+ * 	// Update active block data on click
+ * 	// onclick="getActiveBlockData()"
+ *```
+ *
  * @return {?Object} Selected block.
  */
 export function getSelectedBlock( state ) {