/* exported slice, toString */
/**
* Namespace for all classes, static methods and static properties.
*
* @namespace OO
*/
var
// eslint-disable-next-line no-redeclare
OO = {},
// Optimisation: Local reference to methods from a global prototype
hasOwn = OO.hasOwnProperty,
slice = Array.prototype.slice,
// eslint-disable-next-line no-redeclare
toString = OO.toString;
/* Class Methods */
/**
* Utility to initialize a class for OO inheritance.
*
* Currently this just initializes an empty static object.
*
* @memberof OO
* @method initClass
* @param {Function} fn
*/
OO.initClass = function ( fn ) {
fn.static = fn.static || {};
};
/**
* Inherit from prototype to another using Object#create.
*
* Beware: This redefines the prototype, call before setting your prototypes.
*
* Beware: This redefines the prototype, can only be called once on a function.
* If called multiple times on the same function, the previous prototype is lost.
* This is how prototypal inheritance works, it can only be one straight chain
* (just like classical inheritance in PHP for example). If you need to work with
* multiple constructors consider storing an instance of the other constructor in a
* property instead, or perhaps use a mixin (see OO.mixinClass).
*
* function Thing() {}
* Thing.prototype.exists = function () {};
*
* function Person() {
* Person.super.apply( this, arguments );
* }
* OO.inheritClass( Person, Thing );
* Person.static.defaultEyeCount = 2;
* Person.prototype.walk = function () {};
*
* function Jumper() {
* Jumper.super.apply( this, arguments );
* }
* OO.inheritClass( Jumper, Person );
* Jumper.prototype.jump = function () {};
*
* Jumper.static.defaultEyeCount === 2;
* var x = new Jumper();
* x.jump();
* x.walk();
* x instanceof Thing && x instanceof Person && x instanceof Jumper;
*
* @memberof OO
* @method inheritClass
* @param {Function} targetFn
* @param {Function} originFn
* @throws {Error} If target already inherits from origin
*/
OO.inheritClass = function ( targetFn, originFn ) {
if ( !originFn ) {
throw new Error( 'inheritClass: Origin is not a function (actually ' + originFn + ')' );
}
if ( targetFn.prototype instanceof originFn ) {
throw new Error( 'inheritClass: Target already inherits from origin' );
}
var targetConstructor = targetFn.prototype.constructor;
// [DEPRECATED] Provide .parent as alias for code supporting older browsers which
// allows people to comply with their style guide.
targetFn.super = targetFn.parent = originFn;
targetFn.prototype = Object.create( originFn.prototype, {
// Restore constructor property of targetFn
constructor: {
value: targetConstructor,
enumerable: false,
writable: true,
configurable: true
}
} );
// Extend static properties - always initialize both sides
OO.initClass( originFn );
targetFn.static = Object.create( originFn.static );
};
/**
* Copy over *own* prototype properties of a mixin.
*
* The 'constructor' (whether implicit or explicit) is not copied over.
*
* This does not create inheritance to the origin. If you need inheritance,
* use OO.inheritClass instead.
*
* Beware: This can redefine a prototype property, call before setting your prototypes.
*
* Beware: Don't call before OO.inheritClass.
*
* function Foo() {}
* function Context() {}
*
* // Avoid repeating this code
* function ContextLazyLoad() {}
* ContextLazyLoad.prototype.getContext = function () {
* if ( !this.context ) {
* this.context = new Context();
* }
* return this.context;
* };
*
* function FooBar() {}
* OO.inheritClass( FooBar, Foo );
* OO.mixinClass( FooBar, ContextLazyLoad );
*
* @memberof OO
* @method mixinClass
* @param {Function} targetFn
* @param {Function} originFn
*/
OO.mixinClass = function ( targetFn, originFn ) {
if ( !originFn ) {
throw new Error( 'mixinClass: Origin is not a function (actually ' + originFn + ')' );
}
var key;
// Copy prototype properties
for ( key in originFn.prototype ) {
if ( key !== 'constructor' && hasOwn.call( originFn.prototype, key ) ) {
targetFn.prototype[ key ] = originFn.prototype[ key ];
}
}
// Copy static properties - always initialize both sides
OO.initClass( targetFn );
if ( originFn.static ) {
for ( key in originFn.static ) {
if ( hasOwn.call( originFn.static, key ) ) {
targetFn.static[ key ] = originFn.static[ key ];
}
}
} else {
OO.initClass( originFn );
}
};
/**
* Test whether one class is a subclass of another, without instantiating it.
*
* Every class is considered a subclass of Object and of itself.
*
* @memberof OO
* @method isSubClass
* @param {Function} testFn The class to be tested
* @param {Function} baseFn The base class
* @return {boolean} Whether testFn is a subclass of baseFn (or equal to it)
*/
OO.isSubclass = function ( testFn, baseFn ) {
return testFn === baseFn || testFn.prototype instanceof baseFn;
};
/* Object Methods */
/**
* Get a deeply nested property of an object using variadic arguments, protecting against
* undefined property errors.
*
* `quux = OO.getProp( obj, 'foo', 'bar', 'baz' );` is equivalent to `quux = obj.foo.bar.baz;`
* except that the former protects against JS errors if one of the intermediate properties
* is undefined. Instead of throwing an error, this function will return undefined in
* that case.
*
* @memberof OO
* @method getProp
* @param {Object} obj
* @param {...any} [keys]
* @return {Object|undefined} obj[arguments[1]][arguments[2]].... or undefined
*/
OO.getProp = function ( obj ) {
var retval = obj;
for ( var i = 1; i < arguments.length; i++ ) {
if ( retval === undefined || retval === null ) {
// Trying to access a property of undefined or null causes an error
return undefined;
}
retval = retval[ arguments[ i ] ];
}
return retval;
};
/**
* Set a deeply nested property of an object using variadic arguments, protecting against
* undefined property errors.
*
* `OO.setProp( obj, 'foo', 'bar', 'baz' );` is equivalent to `obj.foo.bar = baz;` except that
* the former protects against JS errors if one of the intermediate properties is
* undefined. Instead of throwing an error, undefined intermediate properties will be
* initialized to an empty object. If an intermediate property is not an object, or if obj itself
* is not an object, this function will silently abort.
*
* @memberof OO
* @method setProp
* @param {Object} obj
* @param {...any} [keys]
* @param {any} [value]
*/
OO.setProp = function ( obj ) {
if ( Object( obj ) !== obj || arguments.length < 2 ) {
return;
}
var prop = obj;
for ( var i = 1; i < arguments.length - 2; i++ ) {
if ( prop[ arguments[ i ] ] === undefined ) {
prop[ arguments[ i ] ] = {};
}
if ( Object( prop[ arguments[ i ] ] ) !== prop[ arguments[ i ] ] ) {
return;
}
prop = prop[ arguments[ i ] ];
}
prop[ arguments[ arguments.length - 2 ] ] = arguments[ arguments.length - 1 ];
};
/**
* Delete a deeply nested property of an object using variadic arguments, protecting against
* undefined property errors, and deleting resulting empty objects.
*
* @memberof OO
* @method deleteProp
* @param {Object} obj
* @param {...any} [keys]
*/
OO.deleteProp = function ( obj ) {
if ( Object( obj ) !== obj || arguments.length < 2 ) {
return;
}
var prop = obj;
var props = [ prop ];
var i = 1;
for ( ; i < arguments.length - 1; i++ ) {
if (
prop[ arguments[ i ] ] === undefined ||
Object( prop[ arguments[ i ] ] ) !== prop[ arguments[ i ] ]
) {
return;
}
prop = prop[ arguments[ i ] ];
props.push( prop );
}
delete prop[ arguments[ i ] ];
// Walk back through props removing any plain empty objects
while (
props.length > 1 &&
( prop = props.pop() ) &&
OO.isPlainObject( prop ) && !Object.keys( prop ).length
) {
delete props[ props.length - 1 ][ arguments[ props.length ] ];
}
};
/**
* Create a new object that is an instance of the same
* constructor as the input, inherits from the same object
* and contains the same own properties.
*
* This makes a shallow non-recursive copy of own properties.
* To create a recursive copy of plain objects, use #copy.
*
* var foo = new Person( mom, dad );
* foo.setAge( 21 );
* var foo2 = OO.cloneObject( foo );
* foo.setAge( 22 );
*
* // Then
* foo2 !== foo; // true
* foo2 instanceof Person; // true
* foo2.getAge(); // 21
* foo.getAge(); // 22
*
* @memberof OO
* @method cloneObject
* @param {Object} origin
* @return {Object} Clone of origin
*/
OO.cloneObject = function ( origin ) {
var r = Object.create( origin.constructor.prototype );
for ( var key in origin ) {
if ( hasOwn.call( origin, key ) ) {
r[ key ] = origin[ key ];
}
}
return r;
};
/**
* Get an array of all property values in an object.
*
* @memberof OO
* @method getObjectValues
* @param {Object} obj Object to get values from
* @return {Array} List of object values
*/
OO.getObjectValues = function ( obj ) {
if ( obj !== Object( obj ) ) {
throw new TypeError( 'Called on non-object' );
}
var values = [];
for ( var key in obj ) {
if ( hasOwn.call( obj, key ) ) {
values[ values.length ] = obj[ key ];
}
}
return values;
};
/**
* Use binary search to locate an element in a sorted array.
*
* searchFunc is given an element from the array. `searchFunc(elem)` must return a number
* above 0 if the element we're searching for is to the right of (has a higher index than) elem,
* below 0 if it is to the left of elem, or zero if it's equal to elem.
*
* To search for a specific value with a comparator function (a `function cmp(a,b)` that returns
* above 0 if `a > b`, below 0 if `a < b`, and 0 if `a == b`), you can use
* `searchFunc = cmp.bind( null, value )`.
*
* @memberof OO
* @method binarySearch
* @param {Array} arr Array to search in
* @param {Function} searchFunc Search function
* @param {boolean} [forInsertion] If not found, return index where val could be inserted
* @return {number|null} Index where val was found, or null if not found
*/
OO.binarySearch = function ( arr, searchFunc, forInsertion ) {
var left = 0;
var right = arr.length;
while ( left < right ) {
// Equivalent to Math.floor( ( left + right ) / 2 ) but much faster
// eslint-disable-next-line no-bitwise
var mid = ( left + right ) >> 1;
var cmpResult = searchFunc( arr[ mid ] );
if ( cmpResult < 0 ) {
right = mid;
} else if ( cmpResult > 0 ) {
left = mid + 1;
} else {
return mid;
}
}
return forInsertion ? right : null;
};
/**
* Recursively compare properties between two objects.
*
* A false result may be caused by property inequality or by properties in one object missing from
* the other. An asymmetrical test may also be performed, which checks only that properties in the
* first object are present in the second object, but not the inverse.
*
* If either a or b is null or undefined it will be treated as an empty object.
*
* @memberof OO
* @method compare
* @param {Object|undefined|null} a First object to compare
* @param {Object|undefined|null} b Second object to compare
* @param {boolean} [asymmetrical] Whether to check only that a's values are equal to b's
* (i.e. a is a subset of b)
* @return {boolean} If the objects contain the same values as each other
*/
OO.compare = function ( a, b, asymmetrical ) {
if ( a === b ) {
return true;
}
a = a || {};
b = b || {};
if ( typeof a.nodeType === 'number' && typeof a.isEqualNode === 'function' ) {
return a.isEqualNode( b );
}
for ( var k in a ) {
if ( !hasOwn.call( a, k ) || a[ k ] === undefined || a[ k ] === b[ k ] ) {
// Ignore undefined values, because there is no conceptual difference between
// a key that is absent and a key that is present but whose value is undefined.
continue;
}
var aValue = a[ k ];
var bValue = b[ k ];
var aType = typeof aValue;
var bType = typeof bValue;
if ( aType !== bType ||
(
( aType === 'string' || aType === 'number' || aType === 'boolean' ) &&
aValue !== bValue
) ||
( aValue === Object( aValue ) && !OO.compare( aValue, bValue, true ) ) ) {
return false;
}
}
// If the check is not asymmetrical, recursing with the arguments swapped will verify our result
return asymmetrical ? true : OO.compare( b, a, true );
};
/**
* Create a plain deep copy of any kind of object.
*
* Copies are deep, and will either be an object or an array depending on `source`.
*
* @memberof OO
* @method copy
* @param {Object} source Object to copy
* @param {Function} [leafCallback] Applied to leaf values after they are cloned but before they are
* added to the clone
* @param {Function} [nodeCallback] Applied to all values before they are cloned. If the
* nodeCallback returns a value other than undefined, the returned value is used instead of
* attempting to clone.
* @return {Object} Copy of source object
*/
OO.copy = function ( source, leafCallback, nodeCallback ) {
var destination;
if ( nodeCallback ) {
// Extensibility: check before attempting to clone source.
destination = nodeCallback( source );
if ( destination !== undefined ) {
return destination;
}
}
if ( Array.isArray( source ) ) {
// Array (fall through)
destination = new Array( source.length );
} else if ( source && typeof source.clone === 'function' ) {
// Duck type object with custom clone method
return leafCallback ? leafCallback( source.clone() ) : source.clone();
} else if ( source && typeof source.cloneNode === 'function' ) {
// DOM Node
return leafCallback ?
leafCallback( source.cloneNode( true ) ) :
source.cloneNode( true );
} else if ( OO.isPlainObject( source ) ) {
// Plain objects (fall through)
destination = {};
} else {
// Non-plain objects (incl. functions) and primitive values
return leafCallback ? leafCallback( source ) : source;
}
// source is an array or a plain object
for ( var key in source ) {
destination[ key ] = OO.copy( source[ key ], leafCallback, nodeCallback );
}
// This is an internal node, so we don't apply the leafCallback.
return destination;
};
/**
* Generate a hash of an object based on its name and data.
*
* Performance optimization: <http://jsperf.com/ve-gethash-201208#/toJson_fnReplacerIfAoForElse>
*
* To avoid two objects with the same values generating different hashes, we utilize the replacer
* argument of JSON.stringify and sort the object by key as it's being serialized. This may or may
* not be the fastest way to do this; we should investigate this further.
*
* Objects and arrays are hashed recursively. When hashing an object that has a .getHash()
* function, we call that function and use its return value rather than hashing the object
* ourselves. This allows classes to define custom hashing.
*
* @memberof OO
* @method getHash
* @param {Object} val Object to generate hash for
* @return {string} Hash of object
*/
OO.getHash = function ( val ) {
return JSON.stringify( val, OO.getHash.keySortReplacer );
};
/**
* Sort objects by key (helper function for OO.getHash).
*
* This is a callback passed into JSON.stringify.
*
* @memberof OO
* @method getHash_keySortReplacer
* @param {string} key Property name of value being replaced
* @param {any} val Property value to replace
* @return {any} Replacement value
*/
OO.getHash.keySortReplacer = function ( key, val ) {
if ( val && typeof val.getHashObject === 'function' ) {
// This object has its own custom hash function, use it
val = val.getHashObject();
}
if ( !Array.isArray( val ) && Object( val ) === val ) {
// Only normalize objects when the key-order is ambiguous
// (e.g. any object not an array).
var normalized = {};
var keys = Object.keys( val ).sort();
for ( var i = 0, len = keys.length; i < len; i++ ) {
normalized[ keys[ i ] ] = val[ keys[ i ] ];
}
return normalized;
} else {
// Primitive values and arrays get stable hashes
// by default. Lets those be stringified as-is.
return val;
}
};
/**
* Get the unique values of an array, removing duplicates.
*
* @memberof OO
* @method unique
* @param {Array} arr Array
* @return {Array} Unique values in array
*/
OO.unique = function ( arr ) {
return Array.from( new Set( arr ) );
};
/**
* Compute the union (duplicate-free merge) of a set of arrays.
*
* @memberof OO
* @method simpleArrayUnion
* @param {Array} a First array
* @param {...Array} rest Arrays to union
* @return {Array} Union of the arrays
*/
OO.simpleArrayUnion = function ( a, ...rest ) {
var set = new Set( a );
for ( var i = 0; i < rest.length; i++ ) {
var arr = rest[ i ];
for ( var j = 0; j < arr.length; j++ ) {
set.add( arr[ j ] );
}
}
return Array.from( set );
};
/**
* Combine arrays (intersection or difference).
*
* An intersection checks the item exists in 'b' while difference checks it doesn't.
*
* @private
* @param {Array} a First array
* @param {Array} b Second array
* @param {boolean} includeB Whether to items in 'b'
* @return {Array} Combination (intersection or difference) of arrays
*/
function simpleArrayCombine( a, b, includeB ) {
var set = new Set( b );
var result = [];
for ( var j = 0; j < a.length; j++ ) {
var isInB = set.has( a[ j ] );
if ( isInB === includeB ) {
result.push( a[ j ] );
}
}
return result;
}
/**
* Compute the intersection of two arrays (items in both arrays).
*
* @memberof OO
* @method simpleArrayIntersection
* @param {Array} a First array
* @param {Array} b Second array
* @return {Array} Intersection of arrays
*/
OO.simpleArrayIntersection = function ( a, b ) {
return simpleArrayCombine( a, b, true );
};
/**
* Compute the difference of two arrays (items in 'a' but not 'b').
*
* @memberof OO
* @method simpleArrayDifference
* @param {Array} a First array
* @param {Array} b Second array
* @return {Array} Intersection of arrays
*/
OO.simpleArrayDifference = function ( a, b ) {
return simpleArrayCombine( a, b, false );
};