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General purpose node utilities
Table of Contents
Introduction
The Hoek general purpose node utilities library is used to aid in a variety of manners. It comes with useful methods for Arrays (clone, merge, applyToDefaults), Objects (removeKeys, copy), Asserting and more.
For example, to use Hoek to set configuration with default options:
var Hoek = require('hoek');
var default = {url : "www.github.com", port : "8000", debug : true}
var config = Hoek.applyToDefaults(default, {port : "3000", admin : true});
// In this case, config would be { url: 'www.github.com', port: '3000', debug: true, admin: true }
Under each of the sections (such as Array), there are subsections which correspond to Hoek methods. Each subsection will explain how to use the corresponding method. In each js excerpt below, the var Hoek = require('hoek') is omitted for brevity.
Object
Hoek provides several helpful methods for objects and arrays.
clone(obj)
This method is used to clone an object or an array. A deep copy is made (duplicates everything, including values that are objects).
var nestedObj = {
w: /^something$/ig,
x: {
a: [1, 2, 3],
b: 123456,
c: new Date()
},
y: 'y',
z: new Date()
};
var copy = Hoek.clone(nestedObj);
copy.x.b = 100;
console.log(copy.y) // results in 'y'
console.log(nestedObj.x.b) // results in 123456
console.log(copy.x.b) // results in 100
merge(target, source, isNullOverride, isMergeArrays)
isNullOverride, isMergeArrays default to true
Merge all the properties of source into target, source wins in conflic, and by default null and undefined from source are applied
var target = {a: 1, b : 2}
var source = {a: 0, c: 5}
var source2 = {a: null, c: 5}
var targetArray = [1, 2, 3];
var sourceArray = [4, 5];
var newTarget = Hoek.merge(target, source); // results in {a: 0, b: 2, c: 5}
newTarget = Hoek.merge(target, source2); // results in {a: null, b: 2, c: 5}
newTarget = Hoek.merge(target, source2, false); // results in {a: 1, b: 2, c: 5}
newTarget = Hoek.merge(targetArray, sourceArray) // results in [1, 2, 3, 4, 5]
newTarget = Hoek.merge(targetArray, sourceArray, true, false) // results in [4, 5]
applyToDefaults(defaults, options)
Apply options to a copy of the defaults
var defaults = {host: "localhost", port: 8000};
var options = {port: 8080};
var config = Hoek.applyToDefaults(defaults, options); // results in {host: "localhost", port: 8080};
unique(array, key)
Remove duplicate items from Array
var array = [1, 2, 2, 3, 3, 4, 5, 6];
var newArray = Hoek.unique(array); // results in [1,2,3,4,5,6];
array = [{id: 1}, {id: 1}, {id: 2}];
newArray = Hoek.unique(array, "id") // results in [{id: 1}, {id: 2}]
mapToObject(array, key)
Convert an Array into an Object
var array = [1,2,3];
var newObject = Hoek.mapToObject(array); // results in [{"1": true}, {"2": true}, {"3": true}]
array = [{id: 1}, {id: 2}];
newObject = Hoek.mapToObject(array, "id") // results in [{"id": 1}, {"id": 2}]
intersect(array1, array2)
Find the common unique items in two arrays
var array1 = [1, 2, 3];
var array2 = [1, 4, 5];
var newArray = Hoek.intersect(array1, array2) // results in [1]
matchKeys(obj, keys)
Find which keys are present
var obj = {a: 1, b: 2, c: 3};
var keys = ["a", "e"];
Hoek.matchKeys(obj, keys) // returns ["a"]
flatten(array, target)
Flatten an array
var array = [1, 2, 3];
var target = [4, 5];
var flattenedArray = Hoek.flatten(array, target) // results in [4, 5, 1, 2, 3];
removeKeys(object, keys)
Remove keys
var object = {a: 1, b: 2, c: 3, d: 4};
var keys = ["a", "b"];
Hoek.removeKeys(object, keys) // object is now {c: 3, d: 4}
reach(obj, chain)
Converts an object key chain string to reference
var chain = 'a.b.c';
var obj = {a : {b : { c : 1}}};
Hoek.reach(obj, chain) // returns 1
inheritAsync(self, obj, keys)
Inherits a selected set of methods from an object, wrapping functions in asynchronous syntax and catching errors
var targetFunc = function () { };
var proto = {
a: function () {
return 'a!';
},
b: function () {
return 'b!';
},
c: function () {
throw new Error('c!');
}
};
var keys = ['a', 'c'];
Hoek.inheritAsync(targetFunc, proto, ['a', 'c']);
var target = new targetFunc();
target.a(function(err, result){console.log(result)} // returns 'a!'
target.c(function(err, result){console.log(result)} // returns undefined
target.b(function(err, result){console.log(result)} // gives error: Object [object Object] has no method 'b'
rename(obj, from, to)
Rename a key of an object
var obj = {a : 1, b : 2};
Hoek.rename(obj, "a", "c"); // obj is now {c : 1, b : 2}
Timer
A Timer object. Initializing a new timer object sets the ts to the number of milliseconds elapsed since 1 January 1970 00:00:00 UTC.
example :
var timerObj = new Hoek.Timer();
console.log("Time is now: " + timerObj.ts)
console.log("Elapsed time from initialization: " + timerObj.elapsed() + 'milliseconds')
Binary Encoding/Decoding
base64urlEncode(value)
Encodes value in Base64 or URL encoding
base64urlDecode(value)
Decodes data in Base64 or URL encoding.
Escaping Characters
Hoek provides convenient methods for escaping html characters. The escaped characters are as followed:
internals.htmlEscaped = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
"'": ''',
'`': '`'
};
escapeHtml(string)
var string = '<html> hey </html>';
var escapedString = Hoek.escapeHtml(string); // returns <html> hey </html>
escapeHeaderAttribute(attribute)
Escape attribute value for use in HTTP header
var a = Hoek.escapeHeaderAttribute('I said "go w\\o me"'); //returns I said \"go w\\o me\"
escapeRegex(string)
Escape string for Regex construction
var a = Hoek.escapeRegex('4^f$s.4*5+-_?%=#!:@|~\\/`"(>)[<]d{}s,'); // returns 4\^f\$s\.4\*5\+\-_\?%\=#\!\:@\|~\\\/`"\(>\)\[<\]d\{\}s\,
Errors
assert(message)
var a = 1, b =2;
Hoek.assert(a === b, 'a should equal b'); // ABORT: a should equal b
abort(message)
First checks if process.env.NODE_ENV === 'test', and if so, throws error message. Otherwise, displays most recent stack and then exits process.
displayStack(slice)
Displays the trace stack
var stack = Hoek.displayStack();
console.log(stack) // returns something like:
[ 'null (/Users/user/Desktop/hoek/test.js:4:18)',
'Module._compile (module.js:449:26)',
'Module._extensions..js (module.js:467:10)',
'Module.load (module.js:356:32)',
'Module._load (module.js:312:12)',
'Module.runMain (module.js:492:10)',
'startup.processNextTick.process._tickCallback (node.js:244:9)' ]
callStack(slice)
Returns a trace stack array.
var stack = Hoek.callStack();
console.log(stack) // returns something like:
[ [ '/Users/user/Desktop/hoek/test.js', 4, 18, null, false ],
[ 'module.js', 449, 26, 'Module._compile', false ],
[ 'module.js', 467, 10, 'Module._extensions..js', false ],
[ 'module.js', 356, 32, 'Module.load', false ],
[ 'module.js', 312, 12, 'Module._load', false ],
[ 'module.js', 492, 10, 'Module.runMain', false ],
[ 'node.js',
244,
9,
'startup.processNextTick.process._tickCallback',
false ] ]
toss(condition)
toss(condition /*, [message], callback */)
Return an error as first argument of a callback
Load Files
loadPackage(dir)
Load and parse package.json process root or given directory
var pack = Hoek.loadPackage(); // pack.name === 'hoek'
loadDirModules(path, excludeFiles, target)
Loads modules from a given path; option to exclude files (array).