add docs

1 files changed, 120 insertions, 20 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 5da5bdb..95e09f5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,15 +1,126 @@
-pub use directories::{ProjectDirs, UserDirs};
-pub use serde::{de::DeserializeOwned, Serialize};
-pub use serde_json;
-pub use serde_yaml;
-pub use toml;
+//! `fondant` is a macro based library to take the boilerplate out of
+//! configuration handling. Most of `fondant` is based off the `confy` crate.
+//!
+//! `fondant` adds a couple of extra features:
+//!
+//!  - support for json, yaml and toml
+//!  - support for custom config paths
+//!  - support for custom config file names
+//!
+//!  ### Sample usage
+//!
+//! ```
+//! // the struct has to derive Serialize, Deserialize and Default
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "config.toml"]
+//! // |
+//! // `-- this attribute sets the file name to "config.toml"
+//! // `-- the file format to "toml"
+//! // `-- the file path to "default" (read the notes below)
+//! struct AppConfig {
+//!     version: u32,
+//!     port: u32,
+//!     username: String,
+//! }
+//!
+//! fn main() {
+//!     // use `load` (associated method) to load the config file
+//!     let mut conf = AppConfig::load().unwrap();
+//!
+//!     // do stuff with conf
+//!     conf.version = 2;
+//!
+//!     // call `store` to save changes
+//!     conf.store().unwrap();
+//! }
+//! ```
+//! **Notes**:  
+//!  - `load` returns `Default::default` if the config file is not present, and stores
+//!  a serialized `Default::default` at the specified path
+//!  - the "default" config path varies by platform:
+//!     * GNU/Linux: `$XDG_CONFIG_HOME/my_cool_crate/config.toml` (follows xdg spec)
+//!     * MacOS: `$HOME/Library/Preferences/my_cool_crate/config.toml`
+//!     * Windows: `{FOLDERID_RoamingAppData}\_project_path_\config`
+//!
+//! ### Customization
+//!
+//! Set your own filename, for ex.: `apprc`
+//!
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "apprc.toml"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $XDG_CONFIG_HOME/my_cool_crate/apprc.toml
+//! // effective format: toml
+//! ```
+//!
+//! Change file format to `yaml`, by changing the file extension.
+//! Supported extensions are `yaml`, `toml`, `json`:
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "config.yaml"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $XDG_CONFIG_HOME/my_cool_crate/config.yaml
+//! // effective format: yaml
+//! ```
+//!
+//! Override the default config path, for ex.: the home directory
+//! (it is not recommended to override config path):
+//! ```
+//! #[derive(Configure, Serialize, Deserialize, Default)]
+//! #[config_file = "~/.apprc.json"]
+//! struct AppConfig {
+//!     // -- snip --
+//! }
+//! // effective path: $HOME/.apprc.json
+//! // effective format: json
+//! ```
 
-use std::path::{Path, PathBuf};
+/// Re-exporting crates that fondant_derive depends on.
+///
+///
+/// Unfortunately, this seems to be the only way to bring crates into
+/// scope from a proc-macro crate
+/// This module should not bother you
+pub mod fondant_exports {
+    pub use directories::{ProjectDirs, UserDirs};
+    pub use serde::{de::DeserializeOwned, Serialize};
+    pub use serde_json;
+    pub use serde_yaml;
+    use std::path::{Path, PathBuf};
+    pub use toml;
+    pub fn expand_tilde<P: AsRef<Path>>(path: P) -> PathBuf {
+        let p = path.as_ref();
+        if p.starts_with("~") {
+            if p == Path::new("~") {
+                return UserDirs::new().unwrap().home_dir().to_path_buf();
+            } else {
+                let mut h = UserDirs::new().unwrap().home_dir().to_path_buf();
+                h.push(p.strip_prefix("~/").unwrap());
+                return h;
+            }
+        }
+        return p.to_path_buf();
+    }
+}
 
+use serde::{de::DeserializeOwned, Serialize};
 #[derive(Debug)]
+/// Errors that `load` and `store` can result in
 pub enum FondantError {
+    /// Occurs when the home dir is not accessible.
+    /// You should probably `panic!` when this is thrown.
     InvalidHomeDir,
+
+    /// Invalid toml/yaml/json config.
     ConfigParseError,
+
+    /// Invalid permissions to create config dir.
+    /// Might occur when you set config dir to, say, `/etc/config.toml` and run without superuser.
     DirCreateErr(std::io::Error),
     LoadError,
     FileWriteError,
@@ -17,21 +128,10 @@ pub enum FondantError {
     FileOpenError,
 }
 
-pub fn expand_tilde<P: AsRef<Path>>(path: P) -> PathBuf {
-    let p = path.as_ref();
-    if p.starts_with("~") {
-        if p == Path::new("~") {
-            return UserDirs::new().unwrap().home_dir().to_path_buf();
-        } else {
-            let mut h = UserDirs::new().unwrap().home_dir().to_path_buf();
-            h.push(p.strip_prefix("~/").unwrap());
-            return h;
-        }
-    }
-    return p.to_path_buf();
-}
-
+/// Derive this trait on a struct to mark it as a 'configuration' struct.
 pub trait Configure: Serialize + DeserializeOwned + Default {
     fn load() -> Result<Self, FondantError>;
     fn store(&self) -> Result<(), FondantError>;
 }
+
+pub use fondant_derive::Configure;