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#[cfg(feature = "json")]
pub mod featured {
use crate::Error;
use serde::{Deserialize, Serialize};
use std::fs::{read_to_string, write};
use std::io::{BufWriter, Write};
pub trait FromJson: for<'de> Deserialize<'de> {
/// Deserializes an object from a JSON file
/// # Arguments
/// * `filename` - The path of the JSON file to be read
///
/// # Errors
/// * `serde_rw::Error` - If the file could not be read
///
/// # Examples
/// ```
/// use serde_rw::FromJson;
/// use serde::Deserialize;
///
/// #[derive(Debug, Deserialize, Eq, PartialEq)]
/// struct Person {
/// id: u32,
/// name: String,
/// }
///
/// #[cfg(feature = "json")]
/// {
/// assert_eq!(
/// Person::from_json_file("./tests/person.json").unwrap(),
/// Person {
/// id: 1337,
/// name: "John Doe".to_string(),
/// }
/// );
/// }
/// ```
fn from_json_file(filename: &str) -> Result<Self, Error> {
read_to_string(filename)
.map_err(Error::FileError)
.and_then(|text| <Self as FromJson>::from_json_string(&text))
}
/// Deserializes an object from a JSON string
/// # Arguments
/// * `text` - A JSON file's content
///
/// # Errors
/// * `serde_rw::Error` - If the text could not be deserialized
///
/// # Examples
/// ```
/// use serde_rw::FromJson;
/// use serde::Deserialize;
///
/// #[derive(Debug, Deserialize, Eq, PartialEq)]
/// struct Person {
/// id: u32,
/// name: String,
/// }
///
/// const JSON: &str = r#"{"id": 1337, "name": "John Doe"}"#;
///
/// #[cfg(feature = "json")]
/// {
/// assert_eq!(
/// Person::from_json_string(JSON).unwrap(),
/// Person {
/// id: 1337,
/// name: "John Doe".to_string(),
/// }
/// );
/// }
/// ```
fn from_json_string(text: &str) -> Result<Self, Error> {
serde_json::from_str(text).map_err(|error| Error::SerdeError(error.to_string()))
}
}
pub trait ToJson: Serialize {
/// Write object as JSON to a `std::io::Write`r
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn write_json<W>(&self, writer: W) -> Result<(), Error>
where
W: Write,
{
serde_json::to_writer(writer, self)
.map_err(|error| Error::SerdeError(error.to_string()))
}
/// Write object as pretty JSON to a `std::io::Write`
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn write_json_pretty<W>(&self, writer: W) -> Result<(), Error>
where
W: Write,
{
serde_json::to_writer_pretty(writer, self)
.map_err(|error| Error::SerdeError(error.to_string()))
}
/// Return object as serialized JSON string
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn to_json(&self) -> Result<String, Error> {
serde_json::to_string(self).map_err(|error| Error::SerdeError(error.to_string()))
}
/// Return object as prettified JSON string
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn to_json_pretty(&self) -> Result<String, Error> {
let mut writer = BufWriter::new(Vec::new());
<Self as ToJson>::write_json_pretty(self, &mut writer)
.map_err(|error| Error::SerdeError(error.to_string()))?;
String::from_utf8(
writer
.into_inner()
.map_err(|error| Error::SerdeError(error.to_string()))?,
)
.map_err(|error| Error::SerdeError(error.to_string()))
}
/// Write object as serialized JSON string to a file
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn write_to_json_file(&self, filename: &str) -> Result<(), Error> {
write(filename, <Self as ToJson>::to_json(self)?).map_err(Error::FileError)
}
/// Write object as serialized JSON string to a file
/// # Errors
/// Returns an `serde_rw::Error` in case the serialization fails.
fn write_to_json_file_pretty(&self, filename: &str) -> Result<(), Error> {
write(filename, <Self as ToJson>::to_json_pretty(self)?).map_err(Error::FileError)
}
}
}