nconf-lite/lib/nconf/stores/system.js

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No EOL
2.4 KiB
JavaScript

/*
* system.js: Simple memory-based store for process environment variables and
* command-line arguments.
*
* (C) 2011, Charlie Robbins
*
*/
var util = require('util'),
Memory = require('./memory').Memory;
//
// ### function System (options)
// #### @options {Object} Options for this instance.
// Constructor function for the System nconf store, a simple abstraction
// around the Memory store that can read process environment variables
// and command-line arguments.
//
var System = exports.System = function (options) {
Memory.call(this, options);
this.type = 'system';
this.readOnly = true;
this.overrides = options.overrides || null;
this.env = options.env || false;
this.argv = options.argv || false;
};
// Inherit from the Memory store
util.inherits(System, Memory);
//
// ### function loadSync ()
// Loads the data passed in from `process.env` into this instance.
//
System.prototype.loadSync = function () {
if (this.env) {
this.loadEnv();
}
if (this.argv) {
this.loadArgv();
}
if (this.overrides) {
this.loadOverrides();
}
return this.store;
};
//
// ### function loadOverrides ()
// Loads any overrides set on this instance into
// the underlying managed `Memory` store.
//
System.prototype.loadOverrides = function () {
if (!this.overrides) {
return;
}
var self = this,
keys = Object.keys(this.overrides);
keys.forEach(function (key) {
self.set(key, self.overrides[key]);
});
return this.store;
};
//
// ### function loadArgv ()
// Loads the data passed in from the command-line arguments
// into this instance.
//
System.prototype.loadArgv = function () {
var self = this,
argv;
if (typeof this.argv === 'object') {
argv = require('optimist').options(this.argv).argv;
}
else if (this.argv) {
argv = require('optimist').argv;
}
if (!argv) {
return;
}
Object.keys(argv).forEach(function (key) {
self.set(key, argv[key]);
});
return this.store;
};
//
// ### function loadEnv ()
// Loads the data passed in from `process.env` into this instance.
//
System.prototype.loadEnv = function () {
var self = this;
if (!this.env) {
return;
}
Object.keys(process.env).filter(function (key) {
return !self.env.length || self.env.indexOf(key) !== -1;
}).forEach(function (key) {
self.set(key, process.env[key]);
});
return this.store;
};