0.1.1 page navigation

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "up-api"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 description = "A convenient and easy to use wrapper for the Up Bank API."
 license = "MIT OR Apache-2.0"

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.

src/v1/accounts.rs

@@ -194,3 +194,7 @@ impl Client {
         }
     }
 }
+
+// ----------------- Page Navigation -----------------
+
+implement_pagination_v1!(ListAccountsResponse);

src/v1/macros.rs

@@ -0,0 +1,59 @@
+macro_rules! implement_pagination_v1 {
+    ($t:ty) => {
+        impl $t {
+            async fn follow_link(client : &Client, url : &str) -> Result<Self, error::Error> {
+                let res = reqwest::Client::new()
+                    .get(url)
+                    .header("Authorization", client.auth_header())
+                    .send()
+                    .await
+                    .map_err(error::Error::Request)?;
+
+                match res.status() {
+                    reqwest::StatusCode::OK => {
+                        let body = res.text().await.map_err(error::Error::BodyRead)?;
+                        let response : Self = serde_json::from_str(&body).map_err(error::Error::Json)?;
+
+                        Ok(response)
+                    },
+                    _ => {
+                        let body = res.text().await.map_err(error::Error::BodyRead)?;
+                        let error : error::ErrorResponse = serde_json::from_str(&body).map_err(error::Error::Json)?;
+
+                        Err(error::Error::Api(error))
+                    }
+                }
+            }
+
+            /// Follows the link to the next page, returns None of the next page does not exist.
+            pub async fn next(&self, client : &Client) -> Option<Result<Self, error::Error>> {
+                match
+                    self
+                    .links
+                    .next
+                    .as_ref()
+                    .map(|url| Self::follow_link(client, &url)) {
+                        
+                    Some(data) => Some(data.await),
+                    None => None,
+                }
+            }
+
+            /// Follows the link to the previous page, returns None of the previous page does not exist.
+            pub async fn prev(&self, client : &Client) -> Option<Result<Self, error::Error>> {
+                match
+                    self
+                    .links
+                    .prev
+                    .as_ref()
+                    .map(|url| Self::follow_link(client, &url)) {
+                        
+                    Some(data) => Some(data.await),
+                    None => None,
+                }
+            }
+        }
+    }
+}
+
+

src/v1/mod.rs

@@ -1,3 +1,6 @@
+#[macro_use]
+mod macros;
+
 /// Error types and trait implementations.
 pub mod error;
 /// Types for modelling and interacting with [accounts](https://developer.up.com.au/#accounts).
@@ -13,6 +16,7 @@ pub mod utilities;
 /// Types which are stardized (and named) across many resources.
 pub mod standard;
 
+
 static BASE_URL : &str = "https://api.up.com.au/api/v1";
 
 /// A client for interacting with the Up API.

src/v1/tags.rs

@@ -194,3 +194,6 @@ impl Client {
     }
 }
 
+// ----------------- Page Navigation -----------------
+
+implement_pagination_v1!(ListTagsResponse);

src/v1/transactions.rs

@@ -378,3 +378,8 @@ impl Client {
         }
     }
 }
+
+
+// ----------------- Page Navigation -----------------
+
+implement_pagination_v1!(ListTransactionsResponse);