tutorial

docz/docs/02-getting-started/02-example.mdx

@@ -13,7 +13,23 @@ The discussion focuses on the problem solving mindset.  API details are covered
 in other parts of the documentation.
 
 The goal of this example is to generate a XLSX workbook of US President names
-and birthdays.  [Click here](#live-demo) to jump to the live demo.
+and birthdays.  [Click here](#live-demo) to jump to the live demo. The sequence
+diagram below shows the process:
+
+```mermaid
+sequenceDiagram
+  actor U as User
+  participant P as Page
+  participant A as API
+  U->>P: click button
+  P->>A: fetch data
+  A->>P: raw data
+  Note over P: process data
+  Note over P: make workbook
+  Note over P: setup download
+  P->>U: download workbook
+```
+
 
 ## Acquire Data
 
@@ -589,7 +605,7 @@ const make_workbook = async() => {
   const filename = RNFetchBlob.fs.dirs.DocumentDir + "/Presidents.xlsx";
   await RNFetchBlob.fs.writeFile(filename, Array.from(buf), 'ascii');
 
-  return file;
+  return filename;
 };
 
 const App = () => ( <SafeAreaView><View style={{ marginTop: 32, padding: 24 }}>