Add fromJSON

Author: fcollonval

javascript/src/api.ts

@@ -295,6 +295,13 @@ export interface ISharedNotebook extends ISharedDocument {
    */
   deleteCellRange(from: number, to: number): void;
 
+  /**
+   * Override the notebook with a JSON-serialized document.
+   * 
+   * @param value The notebook
+   */
+  fromJSON(value: nbformat.INotebookContent): void;
+
   /**
    * Serialize the model to JSON.
    */

javascript/src/ymodels.ts

@@ -1524,6 +1524,34 @@ export class YNotebook
     this.ymeta.set('metadata', { ...this.getMetadata(), ...value });
   }
 
+  /**
+   * Override the notebook with a JSON-serialized document.
+   * 
+   * @param value The notebook
+   */
+  fromJSON(value: nbformat.INotebookContent): void {
+    this.transact(() => {
+      this.nbformat = value.nbformat;
+      this.nbformat_minor = value.nbformat_minor;
+
+      const metadata = value.metadata;
+      if (metadata['orig_nbformat'] !== undefined) {
+        delete metadata['orig_nbformat'];
+      }
+      this.metadata = metadata;
+
+      const useId = value.nbformat === 4 && value.nbformat_minor >= 5;
+      const ycells = value.cells.map(cell => {
+        if (!useId) {
+          delete cell.id;
+        }
+        return cell;
+      });
+      this.insertCells(this.cells.length, ycells);
+      this.deleteCellRange(0, this.cells.length);
+    });
+  }
+
   /**
    * Serialize the model to JSON.
    */

javascript/test/ymodels.spec.ts

@@ -321,6 +321,61 @@ describe('@jupyter-notebook/ydoc', () => {
         ]);
       });
     });
+
+    describe('#fromJSON', () => {
+      it('should load a serialize notebook', () => {
+        const notebook = new YNotebook();
+        notebook.fromJSON({
+          cells: [],
+          metadata: {
+            dummy: 42
+          },
+          nbformat: 4,
+          nbformat_minor: 5
+        });
+
+        expect(notebook.cells).toHaveLength(0);
+        expect(notebook.nbformat).toEqual(4);
+        expect(notebook.nbformat_minor).toEqual(5);
+      });
+
+      it('should remove orig_nbformat', () => {
+        const notebook = new YNotebook();
+        notebook.fromJSON({
+          cells: [],
+          metadata: {
+            dummy: 42,
+            orig_nbformat: 3
+          },
+          nbformat: 4,
+          nbformat_minor: 5
+        });
+
+        expect(notebook.getMetadata('orig_nbformat')).toEqual(undefined);
+      });
+
+      it('should remove cell id for version <4.5', () => {
+        const notebook = new YNotebook();
+        notebook.fromJSON({
+          cells: [
+            {
+              cell_type: 'code',
+              id: 'first-cell',
+              source: '',
+              metadata: {}
+            }
+          ],
+          metadata: {
+            dummy: 42
+          },
+          nbformat: 4,
+          nbformat_minor: 4
+        });
+
+        expect(notebook.cells).toHaveLength(1);
+        expect(notebook.cells[0].id).not.toEqual('first-cell');
+      });
+    });
   });
 
   describe('YCell standalone', () => {