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README.md

@@ -4,11 +4,20 @@ A convenient and easy to use wrapper for the [Up Bank API](https://developer.up.
 
 ## Example
 
-The following example shows the calculation of the sum of all transactions after a given date (up to the page limit).
+The following example shows the calculation of the sum of all earnings (transactions with positive value) since a given date:
 
 ```
 use up_api::v1::Client;
-use up_api::v1::transactions::ListTransactionsOptions;
+use up_api::v1::transactions::{ListTransactionsOptions, TransactionResource};
+
+fn sum_earnings(transactions : &Vec<TransactionResource>) -> f32 {
+    transactions
+    .iter()
+    .map(|t| &t.attributes.amount.value)
+    .map(|v| v.parse::<f32>().unwrap())
+    .filter(|a| a > &0.0)
+    .sum()
+}
 
 #[tokio::main]
 async fn main() {
@@ -17,19 +26,20 @@ async fn main() {
     let client = Client::new(token.to_string());
 
     let mut options = ListTransactionsOptions::default();
-    options.filter_since("2020-01-01T01:02:03Z".to_string());
+    options.filter_since("2022-01-01T00:00:00Z".to_string());
     options.page_size(100);
 
-    let transactions = client.list_transactions(&options).await.unwrap();
+    let mut transactions = client.list_transactions(&options).await.unwrap();
 
-    let total : f32 =
-        transactions
-        .data
-        .into_iter()
-        .map(|t| t.attributes.amount.value)
-        .map(|v| v.parse::<f32>().unwrap())
-        .filter(|a| a > &0.0)
-        .sum();
+    let mut total = sum_earnings(&transactions.data);
+
+    while let Some(next_page) = transactions.next(&client).await {
+        let next_page = next_page.unwrap();
+        
+        total = total + sum_earnings(&next_page.data);
+
+        transactions = next_page;
+    }
 
     println!("{}", total);
 }
@@ -38,4 +48,3 @@ async fn main() {
 ## Planned Features
 
 - Currently this API wrapper supports all of the `v1` Up API endpoints except [webhooks](https://developer.up.com.au/#webhooks). This is planned for a (hopefully soon) future release.
-- Functions `prev` and `next` on the reslts of paginated endpoints are planned to make moving between pages significantly easier.