Query content model blocks.

packages/roosterjs-content-model-api/lib/index.ts

@@ -60,3 +60,4 @@ export { setModelIndentation } from './modelApi/block/setModelIndentation';
 export { matchLink } from './modelApi/link/matchLink';
 export { promoteLink } from './modelApi/link/promoteLink';
 export { getListAnnounceData } from './modelApi/list/getListAnnounceData';
+export { queryContentModelBlocks } from './modelApi/common/queryContentModelBlocks';

packages/roosterjs-content-model-api/lib/modelApi/common/queryContentModelBlocks.ts

@@ -0,0 +1,77 @@
+import type {
+    ContentModelBlockType,
+    ReadonlyContentModelBlock,
+    ReadonlyContentModelBlockBase,
+    ReadonlyContentModelBlockGroup,
+} from 'roosterjs-content-model-types';
+
+/**
+ * Query content model blocks
+ * @param group The block group to query
+ * @param type The type of block to query
+ * @param filter Optional selector to filter the blocks
+ * @param findFirstOnly True to return the first block only, false to return all blocks
+ */
+export function queryContentModelBlocks<T extends ReadonlyContentModelBlock>(
+    group: ReadonlyContentModelBlockGroup,
+    type: T extends ReadonlyContentModelBlockBase<infer U> ? U : never,
+    filter?: (element: T) => element is T,
+    findFirstOnly?: boolean
+): T[] {
+    const elements: T[] = [];
+    for (let i = 0; i < group.blocks.length; i++) {
+        if (findFirstOnly && elements.length > 0) {
+            return elements;
+        }
+        const block = group.blocks[i];
+
+        switch (block.blockType) {
+            case 'Paragraph':
+            case 'Divider':
+            case 'Entity':
+                if (isExpectedBlockType(block, type, filter)) {
+                    elements.push(block);
+                }
+                break;
+            case 'BlockGroup':
+                if (isExpectedBlockType(block, type, filter)) {
+                    elements.push(block);
+                }
+                const results = queryContentModelBlocks<T>(block, type, filter, findFirstOnly);
+                elements.push(...results);
+                break;
+            case 'Table':
+                if (isExpectedBlockType(block, type, filter)) {
+                    elements.push(block);
+                }
+                for (const row of block.rows) {
+                    for (const cell of row.cells) {
+                        const results = queryContentModelBlocks<T>(
+                            cell,
+                            type,
+                            filter,
+                            findFirstOnly
+                        );
+                        elements.push(...results);
+                    }
+                }
+                break;
+        }
+    }
+    return elements;
+}
+
+function isExpectedBlockType<T extends ReadonlyContentModelBlock>(
+    block: ReadonlyContentModelBlock,
+    type: ContentModelBlockType,
+    filter?: (element: T) => element is T
+): block is T {
+    return isBlockType<T>(block, type) && (!filter || filter(block));
+}
+
+function isBlockType<T extends ReadonlyContentModelBlock>(
+    block: ReadonlyContentModelBlock,
+    type: ContentModelBlockType
+): block is T {
+    return block.blockType == type;
+}