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use config::{Config, File, FileExtensions, Format, Map, Value, ValueKind};
fn main() {
let config = Config::builder()
.add_source(File::from_str("bad", MyFormat))
.add_source(File::from_str("good", MyFormat))
.build();
match config {
Ok(cfg) => println!("A config: {:#?}", cfg),
Err(e) => println!("An error: {}", e),
}
}
#[derive(Debug, Clone)]
pub struct MyFormat;
impl Format for MyFormat {
fn parse(
&self,
uri: Option<&String>,
text: &str,
) -> Result<Map<String, config::Value>, Box<dyn std::error::Error + Send + Sync>> {
// Let's assume our format is somewhat crippled, but this is fine
// In real life anything can be used here - nom, serde or other.
//
// For some more real-life examples refer to format implementation within the library code
let mut result = Map::new();
if text == "good" {
result.insert(
"key".to_string(),
Value::new(uri, ValueKind::String(text.into())),
);
} else {
println!("Something went wrong in {:?}", uri);
}
Ok(result)
}
}
// As crazy as it seems for config sourced from a string, legacy demands its sacrifice
// It is only required for File source, custom sources can use Format without caring for extensions
static MY_FORMAT_EXT: Vec<&'static str> = vec![];
impl FileExtensions for MyFormat {
fn extensions(&self) -> &'static [&'static str] {
&MY_FORMAT_EXT
}
}
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