[][src]Crate lazy_conf

The Primary purpose of this module is to provide a super quick way of accessing and prioritizing the three main configuration options:

  • Arguments as Flags
  • Environment Variables
  • Configuration Files

For configuration files I use the lazyf format, which is straight forward to use:

For example, the contents of "test_data/powers.lz":

This example is not tested
Superman:
    power:fly
    age:30

#comment

Batman:
    power:money
    home:Gotham

The structure is only 2 layers deep, and uses any whitespace to indicate that this row is a child or the previous untabbed row.

Intended Use

The intended use of the program is as follows Assuming the previous file is in one of the supplied locations.

use lazy_conf::config;

// note: this has to be "mut" so help messages can be added
// note: this will load the "test_data/powers" file described above
let mut cfg =
config("-c",&["test_data/powers.lz","{HOME}/.config/myprogram.lz"])
                .unwrap();
                //only fails if -c was provided, but badly formed


// Use grab builder to get the info out.
// note: The help method makes a uses all of the previous cf,fg and env 
//  calls to build a useful message to the user.
let spower = cfg.grab()
                .cf("Superman.power") 
                .fg("-sppower")
                .env("SUPERMAN_POWER")
                .help("What power") 
                .s();

assert_eq!(spower,Some("fly".to_string()));


// You can search multiple elements of the same kind.
// If the first is not available the second will be chosen:
let home = cfg.grab()
                .cf("Superman.home")
                .cf("Batman.home").s();

assert_eq!(home,Some("Gotham".to_string()));

// s() closes returning an Option<String>, 
// t() closes returning a Result<T> where T:FromStr

let age = cfg.grab().cf("Superman.age").t::<i32>();

assert_eq!(age,Ok(30));

// The "help" method, checks for the presence of a "--help" in the
// arguments, if found: it prints the compiled help info.

if cfg.help("A Program to collect Superpowers") {
    // if flag --help existed, cfg prints collated help messages,
    // and returns true
    return;
}

// to see the message we can call 
let hs = cfg.help_string("My Program");
assert_eq!(&hs,"\
My Program
Config file location flag: \"-c\"
default locations : [\"test_data/powers.lz\", \"{HOME}/.config/myprogram.lz\"]
What power:
\tConf:Superman.power,\tFlag:-sppower,\tEnv:SUPERMAN_POWER,\n\n"); 

Loading Files

This example is not tested
let cfg = config("-c",[loc1,loc2,loc3,etc]);

The given flag ("-c") allows the user to supply a different path for the main config file.

This example is not tested
myprogram -c localconf.lz

Whether or not this flag is supplied, the program will attempt to load all files.

It is not considered an error even if none are found.

When an lz request is made, it will search them all (preloaded) in order "-c", "loc1" ,"loc2", ...

Re-exports

pub use crate::get::Getable;
pub use crate::get::GetHolder;
pub use crate::get::GetMode;
pub use crate::env::EnvGetter;

Modules

env
get

Structs

FlagGetter
Lz
LzList

Enums

LzErr

Functions

config

create a config loader object, so each individual config item can be built up and help items can be added too. fails if user provided flag for c_loc_flag, but it was badly formed.

load_local