Add example for handling custom serialization

docs/_includes/examples/custom_serialization.rs

@@ -0,0 +1,48 @@
+use schemars::{schema_for, JsonSchema};
+use serde::{Deserialize, Serialize};
+
+// `int_as_string` and `bool_as_string` use the schema for `String`.
+#[derive(Default, Deserialize, Serialize, JsonSchema)]
+pub struct MyStruct {
+    #[serde(default = "eight", with = "as_string")]
+    #[schemars(with = "String")]
+    pub int_as_string: i32,
+    #[serde(default = "eight")]
+    pub int_normal: i32,
+    #[serde(default, with = "as_string")]
+    #[schemars(with = "String")]
+    pub bool_as_string: bool,
+    #[serde(default)]
+    pub bool_normal: bool,
+}
+
+fn eight() -> i32 {
+    8
+}
+
+// This module serializes values as strings
+mod as_string {
+    use serde::{de::Error, Deserialize, Deserializer, Serializer};
+
+    pub fn serialize<T, S>(value: &T, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        T: std::fmt::Display,
+        S: Serializer,
+    {
+        serializer.collect_str(value)
+    }
+
+    pub fn deserialize<'de, T, D>(deserializer: D) -> Result<T, D::Error>
+    where
+        T: std::str::FromStr,
+        D: Deserializer<'de>,
+    {
+        let string = String::deserialize(deserializer)?;
+        string.parse().map_err(|_| D::Error::custom("Input was not valid"))
+    }
+}
+
+fn main() {
+    let schema = schema_for!(MyStruct);
+    println!("{}", serde_json::to_string_pretty(&schema).unwrap());
+}