feat: add common usage examples of derive_builder

Cargo.toml

@@ -21,6 +21,8 @@ tracing-subscriber = { version = "0.3.18", features = ["env-filter"] }
 
 [dev-dependencies]
 axum = { version = "0.7.5", features = ["http2", "query", "tracing"] }
+chrono = "0.4.38"
+derive_builder = "0.20.0"
 rand = "0.8.5"
 serde = { version = "1.0.203", features = ["derive"] }
 serde_json = "1.0.120"

examples/builder.rs

@@ -0,0 +1,78 @@
+use anyhow::Result;
+use chrono::{DateTime, Utc};
+use derive_builder::Builder;
+
+#[allow(unused)]
+#[derive(Debug, Clone)]
+enum Sensor {
+    Temperature,
+    Pressure,
+    Humidity,
+    Lightning,
+    Vibration,
+    Smoke,
+}
+
+#[allow(unused)]
+#[derive(Builder, Debug)]
+#[builder(setter(into))]
+struct Device {
+    id: u64,
+
+    name: String,
+
+    device_type: Sensor,
+
+    #[builder(setter(custom))]
+    create_date: DateTime<Utc>,
+
+    #[builder(setter(skip), default = "self.running_time_default()")]
+    running_time: u64,
+
+    #[builder(default, setter(into, strip_option))]
+    location: Option<String>,
+
+    #[builder(default = "true")]
+    is_active: bool,
+
+    #[builder(default = "vec![]", setter(each(name = "data_value")))]
+    data: Vec<String>,
+}
+
+fn main() -> Result<()> {
+    let device = Device::builder()
+        .id("29388844402912".parse::<u64>()?)
+        .name("temperature sensor")
+        .device_type(Sensor::Temperature)
+        .create_date("2024-07-01T12:34:56Z")
+        .data_value("30.3".into())
+        .data_value("26.8".into())
+        .build()?;
+
+    println!("{:#?}", device);
+
+    Ok(())
+}
+
+impl Device {
+    pub fn builder() -> DeviceBuilder {
+        DeviceBuilder::default()
+    }
+}
+
+impl DeviceBuilder {
+    pub fn create_date(&mut self, value: &str) -> &mut Self {
+        self.create_date = value.parse::<DateTime<Utc>>().ok();
+        self
+    }
+
+    fn running_time_default(&self) -> u64 {
+        match self.create_date {
+            Some(date) => {
+                let time = Utc::now() - date;
+                time.num_days() as u64
+            }
+            None => 0,
+        }
+    }
+}