add support of clap derive feature #15

Signed-off-by: Benjamin Coenen <[email protected]>

Cargo.toml

@@ -1,3 +1,2 @@
 [workspace]
 members = ["twelf", "config-derive"]
-

README.md

@@ -49,6 +49,7 @@ struct Conf {
 
 // Will generate global arguments for each of your fields inside your configuration struct
 let app = clap::Command::new("test").args(&Conf::clap_args());
+// If you're looking for how to use with clap derive feature, check in the examples directory (twelf/examples/clap_derive.rs)
 
 // Init configuration with layers, each layers override only existing fields
 let config = Conf::with_layers(&[
@@ -67,7 +68,7 @@ Check [here](./twelf/examples) for more examples.
 Twelf supports crate features, if you only want support for `json`, `env` and `toml` then you just have to add this to your `Cargo.toml`
 
 ```toml
-twelf = { version = "0.3", default-features = false, features = ["json", "toml", "env"] }
+twelf = { version = "0.4", default-features = false, features = ["json", "toml", "env"] }
 ```
 
 Default features are `["env", "dhall", "clap", "ini", "json", "yaml", "toml"]`

config-derive/Cargo.toml

@@ -9,7 +9,7 @@
     name        = "config-derive"
     readme      = "README.md"
     repository  = "https://github.com/bnjjj/twelf"
-    version     = "0.3.1"
+    version     = "0.4.0"
 
 
     # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

config-derive/src/lib.rs

@@ -131,7 +131,7 @@ pub fn config(_attrs: TokenStream, item: TokenStream) -> TokenStream {
                 use std::iter::FromIterator;
                 let mut res: std::collections::HashMap<String, ::twelf::reexports::serde_json::Value> = std::collections::HashMap::new();
                 for layer in layers {
-                    let extension = Self::parse(layer)?;
+                    let extension = Self::parse_twelf(layer)?;
                     res.extend(
                         extension
                             .as_object()
@@ -146,11 +146,11 @@ pub fn config(_attrs: TokenStream, item: TokenStream) -> TokenStream {
                     ::twelf::reexports::log::debug!(target: "twelf", "{}={}", key, val);
                 }
 
-                ::twelf::reexports::serde_json::from_value(::twelf::reexports::serde_json::Value::Object(::twelf::reexports::serde_json::Map::from_iter(res.into_iter()))).map_err(|e| ::twelf::Error::Deserialize(e.to_string()))
+                ::twelf::reexports::serde_json::from_value(::twelf::reexports::serde_json::Value::Object(::twelf::reexports::serde_json::Map::from_iter(res.into_iter()))).map_err(|e| ::twelf::Error::Deserialize(format!("config error: {}", e.to_string())))
             }
             #clap_method
 
-            fn parse(priority: &::twelf::Layer) -> Result<::twelf::reexports::serde_json::Value, ::twelf::Error>
+            fn parse_twelf(priority: &::twelf::Layer) -> Result<::twelf::reexports::serde_json::Value, ::twelf::Error>
             {
                 #[derive(::twelf::reexports::serde::Deserialize, ::twelf::reexports::serde::Serialize)]
                 #[serde(crate = "::twelf::reexports::serde")]
@@ -187,15 +187,16 @@ fn build_clap_branch(
         .iter()
         .map(|field_name| field_name.to_kebab_case());
 
+    let field_names_clap_cloned = field_names_clap.clone();
     #[cfg(feature = "clap")]
     let clap_branch = quote! { ::twelf::Layer::Clap(matches) => {
         let mut map: std::collections::HashMap<String, String> = std::collections::HashMap::new();
 
         #(
-            if let Some(vmatch) = matches.value_of(#fields_name) {
+            if let Some(vmatch) = matches.value_of(#field_names_clap_cloned) {
                 map.insert(String::from(#fields_name), vmatch.to_string());
             } else if #fields_is_boolean {
-                if matches.is_present(#fields_name) {
+                if matches.is_present(#field_names_clap_cloned) {
                     map.insert(String::from(#fields_name), String::from("true"));
                 }
             }
@@ -209,7 +210,7 @@ fn build_clap_branch(
     #[cfg(feature = "clap")]
     let clap_method = quote! { pub fn clap_args() -> Vec<::twelf::reexports::clap::Arg<'static>> {
         vec![#(
-           ::twelf::reexports::clap::Arg::new(#fields_name).long(#field_names_clap).help(#docs).takes_value(!#fields_is_boolean).global(true)
+           ::twelf::reexports::clap::Arg::new(#field_names_clap).long(#field_names_clap).help(#docs).takes_value(!#fields_is_boolean).global(true)
         ),*]
     }};
     #[cfg(not(feature = "clap"))]

twelf/Cargo.toml

@@ -9,11 +9,11 @@
     name        = "twelf"
     readme      = "../README.md"
     repository  = "https://github.com/bnjjj/twelf"
-    version     = "0.3.1"
+    version     = "0.4.0"
 
 [dependencies]
-    clap_rs       = { version = "3.0", package = "clap", optional = true }
-    config-derive = { path = "../config-derive", version = "0.3" }
+    clap_rs       = { version = "3.0", package = "clap", optional = true, features = ["derive"] }
+    config-derive = { path = "../config-derive", version = "0.4" }
     envy          = { version = "0.4.1", git = "https://github.com/bnjjj/envy", branch = "master", optional = true }
     log           = "0.4.14"
     serde         = { version = "1", features = ["derive"] }

twelf/examples/clap.rs

@@ -24,4 +24,4 @@ fn main() {
             .unwrap();
 
     println!("config - {:?}", config);
-}
+}

twelf/examples/clap_derive.rs

@@ -0,0 +1,40 @@
+#![allow(dead_code)]
+
+use clap_rs as clap;
+use clap::{Parser, Subcommand, CommandFactory};
+use twelf::{config, Layer};
+
+#[config]
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct Config {
+    #[clap(
+        long,
+        help = "Documentation inside clap, to specifiy db_host",
+    )]
+    db_host: String,
+    #[clap(
+        long,
+        short,
+        help = "The number of threads",
+    )]
+    #[clap(required = false)]
+    threads: usize,
+    #[clap(
+        long,
+        short,
+        help = "Put in verbose mode",
+    )]
+    verbose: bool,
+}
+
+// execute `cargo run --example clap_derive -- --help` to display help and documentation
+// execute `cargo run --example clap_derive -- --db-host localhost --threads 5` to set configuration
+fn main() {
+    let matches = Config::command().ignore_errors(true).get_matches();
+    let config =
+        Config::with_layers(&[Layer::Env(Some(String::from("APP_"))), Layer::Clap(matches)])
+            .unwrap();
+
+    println!("config - {:?}", config);
+}