nconf-lite/lib/nconf/common.js
2017-10-25 22:57:58 -04:00

171 lines
4.3 KiB
JavaScript

/*
* utils.js: Utility functions for the nconf module.
*
* (C) 2011, Charlie Robbins and the Contributors.
*
*/
var fs = require('fs'),
async = require('async'),
formats = require('./formats'),
Memory = require('./stores/memory').Memory;
var common = exports;
//
// ### function path (key)
// #### @key {string} The ':' delimited key to split
// Returns a fully-qualified path to a nested nconf key.
// If given null or undefined it should return an empty path.
// '' should still be respected as a path.
//
common.path = function (key, separator) {
separator = separator || ':';
return key == null ? [] : key.split(separator);
};
//
// ### function key (arguments)
// Returns a `:` joined string from the `arguments`.
//
common.key = function () {
return Array.prototype.slice.call(arguments).join(':');
};
//
// ### function key (arguments)
// Returns a joined string from the `arguments`,
// first argument is the join delimiter.
//
common.keyed = function () {
return Array.prototype.slice.call(arguments, 1).join(arguments[0]);
};
//
// ### function loadFiles (files, callback)
// #### @files {Object|Array} List of files (or settings object) to load.
// #### @callback {function} Continuation to respond to when complete.
// Loads all the data in the specified `files`.
//
common.loadFiles = function (files, callback) {
if (!files) {
return callback(null, {});
}
var options = Array.isArray(files) ? { files: files } : files;
//
// Set the default JSON format if not already
// specified
//
options.format = options.format || formats.json;
function parseFile (file, next) {
fs.readFile(file, function (err, data) {
return !err
? next(null, options.format.parse(data.toString()))
: next(err);
});
}
async.map(options.files, parseFile, function (err, objs) {
return err ? callback(err) : callback(null, common.merge(objs));
});
};
//
// ### function loadFilesSync (files)
// #### @files {Object|Array} List of files (or settings object) to load.
// Loads all the data in the specified `files` synchronously.
//
common.loadFilesSync = function (files) {
if (!files) {
return;
}
//
// Set the default JSON format if not already
// specified
//
var options = Array.isArray(files) ? { files: files } : files;
options.format = options.format || formats.json;
return common.merge(options.files.map(function (file) {
return options.format.parse(fs.readFileSync(file, 'utf8'));
}));
};
//
// ### function merge (objs)
// #### @objs {Array} Array of object literals to merge
// Merges the specified `objs` using a temporary instance
// of `stores.Memory`.
//
common.merge = function (objs) {
var store = new Memory();
objs.forEach(function (obj) {
Object.keys(obj).forEach(function (key) {
store.merge(key, obj[key]);
});
});
return store.store;
};
//
// ### function capitalize (str)
// #### @str {string} String to capitalize
// Capitalizes the specified `str`.
//
common.capitalize = function (str) {
return str && str[0].toUpperCase() + str.slice(1);
};
//
// ### function parseValues (any)
// #### @any {string} String to parse as native data-type or return as is
// try to parse `any` as a native data-type
//
common.parseValues = function (value) {
var val = value;
try {
val = JSON.parse(value);
} catch (ignore) {
// Check for any other well-known strings that should be "parsed"
if (value === 'undefined'){
val = void 0;
}
}
return val;
};
//
// ### function transform(map, fn)
// #### @map {object} Object of key/value pairs to apply `fn` to
// #### @fn {function} Transformation function that will be applied to every key/value pair
// transform a set of key/value pairs and return the transformed result
common.transform = function(map, fn) {
var pairs = Object.keys(map).map(function(key) {
var obj = { key: key, value: map[key]};
var result = fn.call(null, obj);
if (!result) {
return null;
} else if (result.key && typeof result.value !== 'undefined') {
return result;
}
var error = new Error('Transform function passed to store returned an invalid format: ' + JSON.stringify(result));
error.name = 'RuntimeError';
throw error;
});
return pairs.reduce(function(accumulator, pair) {
accumulator[pair.key] = pair.value;
return accumulator;
}, {});
}