Refactoring: Extracted embedded mode as a separate data source

src/datasource/data_source.ts

@@ -6,6 +6,7 @@ export enum DataSourceEnum {
   UPLOADED,
   GEDCOM_URL,
   WIKITREE,
+  EMBEDDED,
 }
 
 /** Source specification together with individual selection. */

src/datasource/embedded.ts

@@ -0,0 +1,82 @@
+import {analyticsEvent} from '../util/analytics';
+import {DataSource, DataSourceEnum, SourceSelection} from './data_source';
+import {getSoftware, TopolaData} from '../util/gedcom_util';
+import {loadGedcom} from './load_data';
+
+/**
+ * Message types used in embedded mode.
+ * When the parent is ready to receive messages, it sends PARENT_READY.
+ * When the child (this app) is ready to receive messages, it sends READY.
+ * When the child receives PARENT_READY, it sends READY.
+ * When the parent receives READY, it sends data in a GEDCOM message.
+ */
+enum EmbeddedMessageType {
+  GEDCOM = 'gedcom',
+  READY = 'ready',
+  PARENT_READY = 'parent_ready',
+}
+
+/** Message sent to parent or received from parent in embedded mode. */
+interface EmbeddedMessage {
+  message: EmbeddedMessageType;
+}
+
+interface GedcomMessage extends EmbeddedMessage {
+  message: EmbeddedMessageType.GEDCOM;
+  gedcom?: string;
+}
+
+export interface EmbeddedSourceSpec {
+  source: DataSourceEnum.EMBEDDED;
+}
+
+/** GEDCOM file received from outside of the iframe. */
+export class EmbeddedDataSource implements DataSource<EmbeddedSourceSpec> {
+  isNewData(
+    newSource: SourceSelection<EmbeddedSourceSpec>,
+    oldSource: SourceSelection<EmbeddedSourceSpec>,
+    data?: TopolaData,
+  ): boolean {
+    // Never reload data.
+    return false;
+  }
+
+  private async onMessage(
+    message: EmbeddedMessage,
+    resolve: (value: TopolaData) => void,
+    reject: (reason: any) => void,
+  ) {
+    if (message.message === EmbeddedMessageType.PARENT_READY) {
+      // Parent didn't receive the first 'ready' message, so we need to send it again.
+      window.parent.postMessage({message: EmbeddedMessageType.READY}, '*');
+    } else if (message.message === EmbeddedMessageType.GEDCOM) {
+      const gedcom = (message as GedcomMessage).gedcom;
+      if (!gedcom) {
+        return;
+      }
+      try {
+        const data = await loadGedcom('', gedcom);
+        const software = getSoftware(data.gedcom.head);
+        analyticsEvent('embedded_file_loaded', {
+          event_label: software,
+        });
+        resolve(data);
+      } catch (error) {
+        analyticsEvent('embedded_file_error');
+        reject(error);
+      }
+    }
+  }
+
+  async loadData(
+    source: SourceSelection<EmbeddedSourceSpec>,
+  ): Promise<TopolaData> {
+    // Notify the parent window that we are ready.
+    return new Promise<TopolaData>((resolve, reject) => {
+      window.parent.postMessage({message: EmbeddedMessageType.READY}, '*');
+      window.addEventListener('message', (data) =>
+        this.onMessage(data.data, resolve, reject),
+      );
+    });
+  }
+}