@fav/prop ver. 1.1.0 API document

assign(dest [, ...srcs) : object

Copys all enumerable own property keys and symbols from one or more source objects to a destination object and returns a destination object.

NOTE: This function behaves the same way as Object.assign except when the first argument is nullish and when properties of first argument object are read only. If the first argument is nullish, this function replace it to an empty plain object. If properties of first argument object are read only, this function ignore them and doesn't throw Errors.

Parameters:

Returns:

The destination object.

Type: object

assignDeep(dest, [, ...srcs]) : object

Copys all enumerable own properties deeply from one or more source objects to a destination object and returns a destination object. This function copys not only child properties but also descendants properties of source objects.

NOTE: This function copys enumerable own properties of srcs objects (top level objects) like Object.assign, but copys properties of child and descendant objects (lower level objects) like primitive properties when those properties are not plain objects. For example:

var src = new function() {
  this.a = { b: 1 };
  this.c = new function() { this.d = 2 };
};
console.log(src); // => { a: { b: 1 }, c: { d: 2 } }

var dest = assignDeep({}, src);
console.log(dest); // => { a: { b: 1 }, c: { d: 2 } }

dest === src // => false
dest.a === src.a // => false
dest.c === src.c // => true

NOTE: If the first argument is nullish, this function replace it to an empty plain object. If properties of first argument object are read only, this function ignore them and doesn't throw Errors.

Parameters:

Returns:

The destination object.

Type: object

defaults(dest [, ...src]) : object

Copys enumerable own properties (both keys and symbols) of source objects to a destination object when each property value is null or undefined. If a property value of a source object is null or undefined, the property is not copied.

NOTE: This function does not throw an error when copying a source property to a destination property which is read only.

Parameters:

Returns:

The destination object.

Type: object

defaultsDeep(dest [, ...src]) : object

Copys enumerable own properties (both keys and symbols) of child and descendant objects of a source object to a destination object when each property value is null or undefined. If a property value of a source object is null or undefined, the property is not copied.

NOTE: This function does not throw an error when copying a source property to a destination property which is read only.

Parameters:

Returns:

The destination object.

Type: object

define.immutable(obj, name, value) : void

Defines an read-only and unenumerable property to the specified object.

Parameters:

define.mutable(obj, name, value) : void

Defines an writable and unenumerable property to the specified object.

Parameters:

define.override(obj, name, fn) : void

Redefines a property function of the specified object.

The original function can be accessed by name.$uper.

define.override(obj, namedFn) : void

Redefines a property function of the specified object with named function.

The original function can be accessed by namedFn.$uper.

enumAllKeys(obj) : Array

Lists enumerable own and inherited property keys of the given object.

This function returns property keys enumerated with "for-in", but returns an empty array if obj is nullish.

Parameter:

Return:

An array of property keys.

Type: Array

enumAllProps(obj) : Array

Lists enumerable own and inherited property keys and symbols of the given object.

This function returns same properties enumerated with "for-in", but returns an empty array when obj is nullish.

Parameter:

Return:

An array of property keys and symbols.

Type: Array

enumAllSymbols(obj) : Array

Lists enumerable own and inherited property symbols of the given object.

This function returns same result with Object.getOwnPropertySymbols except that it returns an empty object when the argument is nullish.

Parameter:

Return:

An array of property symbols.

Type: Array

enumOwnKeys(obj) : Array

Lists own enumerable property keys of a given object.

This function returns the same result of Object.keys(obj), but returns an empty array if obj is nullish.

NOTE: The behavior of Object.keys is different between before and after of Node.js v0.12 when the argument is not an object.

Parameter:

Return:

An array of property keys.

Type: Array

enumOwnProps(obj) : Array

Lists enumerable own property keys and symbols of the given object.

This funciton returns an empty array when the argument is nullish.

Parameter:

Return:

An array of property keys and symbols.

Type: Array

enumOwnSymbols(obj) : Array

Lists enumerable own property symbols of a given object.

This function returns an empty array if obj is nullish.

Parameter:

Return:

An array of property symbols.

Type: Array

getDeep(obj, propPath) : any

Gets a property value in property tree of an object with a property path.

A property path is an array of keys/symbols which are passed from root to a target property in property tree of obj object. For example, the property path of c in { a: { b: { c: 1 } } } is ['a', 'b', 'c'].

This function is targeted at all properties, which are enumerable and unenumerable, own and inherited.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property. (Thus, a property path needs to be always one dimensional array).

Parameters:

Returns:

A property value of a specified property path.

listOwnKeys(obj) : Array

List enumerable and unenumerable own property keys of the given object.

This function returns the same result of Object.getOwnPropertyNames in strict mode except that this function returns an empty array when obj is nullish.

NOTE: The result of Object.getOwnPropertyNames for a function in strict mode is different between before and after Node.js (io.js) v3. On v3 and later it doesn't contain the properties arguments and callar. This function excludes arguments and caller properties even not in strict mode for same behaviors on all versions of Node.js.

NOTE: On some browsers, Chrome, Safari, Vivaldi, Edge and IE, the result of Object.getOwnPropertyNames for a function in non-strict mode is different from in strict mode. It contains the properties arguments and caller. This function excludes arguments and caller properties even not in strict mode for same behaviors on other platforms.

NOTE: The results of Object.getOwnPropertyNames for a function on IE and a no name function on Edge are different from results on other browsers and Node.js. Those do not contain name property. This function appends name property to the result on IE or Edge for same behaviors on target browsers and Node.js

NOTE: The value of name property of a no-name function is the first assigned variable's name on Node.js v6 or later, and that value is an empty string on the eariler. This function does no treatment about this differeneces.

NOTE: On some browsers, Chrome, Firefox, Safari, and Vivaldi, the name property of a no-name function is the first assigned variable's name. On Edge, that name property is an empty string. On IE, that name property is undefined. This function does no treatment about this differeneces.

Parameter:

Return:

An array of property keys.

Type: Array

listOwnProps(obj) : Array

Lists enumerable and unenumerable own property keys and symbols of the given object.

This function returns an array of keys and symbols which are same with the concatenation of Object.getOwnPropertyNames and Object.getOwnPropertySymbols results in strict mode except that this function returns an empty array when obj is nullish.

NOTE: The result of Object.getOwnPropertyNames for a function in strict mode is different between before and after Node.js (io.js) v3. On v3 and later it doesn't contain the properties arguments and caller. This function excludes arguments and caller properties even not in strict mode for same behaviors on all versions of Node.js.

NOTE: On some browsers, Chrome, Safari, Vivaldi, Edge and IE, the result of Object.getOwnPropertyNames for a function in non-strict mode is different from in strict mode. It contains the properties arguments and caller. This function excludes arguments and caller properties even not in strict mode for same behaviors on other platforms.

NOTE: The results of Object.getOwnPropertyNames for a function on IE and a no name function on Edge are different from results on other browsers and Node.js. It does not contain name property. This function appends name property to the result on IE or Edge for same behaviors on target browsers and Node.js

NOTE: The value of name property of a no-name function is the first assigned variable's name on Node.js v6 or later, and that value is an empty string on the eariler. This function does no treatment about this differeneces.

NOTE: On some browsers, Chrome, Firefox, Safari, and Vivaldi, the name property of a no-name function is the first assigned variable's name. On Edge, that name property is an empty string. On IE, that name property is undefined. This function does no treatment about this differeneces.

Parameter:

Return:

An array of property keys and symbols.

Type: Array

listOwnSymbols(obj) : Array

Lists enumerable and unenumerable own property symbols of a given object.

This function returns an empty array if obj is nullish.

Parameter:

Return:

An array of property symbols.

Type: Array

omit(src, omittedProps) : object

Creates a new plain object and copies enumerable own properties (keys and symbols) of src object, but the properties which are included in omittedProps are omitted.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property.

Parameters:

Returns:

A plain object which is copied property keys and symbols of a source object.

omitDeep(src, omittedPropPaths) : object

Creates a new plain object and copies child and descendant enumerable own properties (keys and symbols) of src object deeply, but the properties which are included in omittedPropPaths are omitted.

omittedPropPaths is an array of property paths. A property path is an array of keys/symbols which are passed from root to a target property in property tree of src object. For example, the property path of c in { a: { b: { c: 1 } } } => ['a', 'b', 'c'].

For a top property, a string key or a symbol can be specified. For omitting one property, a prperty path can be specified.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property. (Thus, a property path needs to be always one dimensional array).

Parameters:

Returns:

A plain object which is copied properties deeply except specified.

pick(src, pickedProps) : object

Creates a new plain object and copies enumerable own properties (keys and symbols) of src object, and the copied properties are only included in pickedProps.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property.

Parameters:

Returns:

A plain object which is copied property keys and symbols of a source object.

pickDeep(src, pickedPropPaths) : object

Creates a new plain object and copies child and descendant enumerable own properties (keys and symbols) of src object deeply, and the properties which are included in pickedPropPaths are picked.

pickedPropPaths is an array of property paths. A property path is an array of keys/symbols which are passed from root to a target property in property tree of src object. For example, the property path of c in { a : { b: { c: 1 } } } => ['a', 'b', 'c']. For a top property, a string or a symbol can be specified.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property. (Thus, a property path needs to be always one dimensional array).

Parameters:

Returns:

A plain object which is copied property paths keys.

setDeep(obj, propPath, value) : Void

Sets a property value in property tree of an object with a property path.

A property path is an array of keys/symbols which are passed from root to a target property in property tree of obj object. For example, the property path of c in { a: { b: { c: 1 } } } is ['a', 'b', 'c']. For a top property, a string or a symbol can be specified.

This function is targeted at all properties, which are enumerable and unenumerable, own and inherited. If target property is read only, this function does nothing and throws no error.

NOTE: All versions of Node.js allows to use a string array for getting or setting property, like obj[['a','b']] == obj['a,b']. An Symbol array is allowed as same until v4, but is not allowed on v5 and later (TypeError is thrown). To support same behaviors for all versions, this function does not allow to use an array as a property. (Thus, a property path needs to be always one dimensional array).

Parameters:

visit(obj, fn) : Void

Visits each nodes in a plain object tree. This function deeply traces property nodes which are plain objects only, and apply a given function to enumerable and own properties (keys and symbols) of the traced property nodes.

Parameters:

The second argument function is passed following parameters, and the return value of this function controls if this function is applied to child and descendant properties of current property.

• APIs of the second argument function

  Parameter:

  Parameter	Type	Description
  key	string	A key of current property.
  value	any	A value of current property.
  index	number	Index of current property among sibling properties.
  count	number	Count of sibling properties.
  parentKeys	Array	An array which contains keys of ancestor properties and represents a trace path to current property. Also, the length of this array suggests the depth of property tree.
  parentNode	object	A plain object which is a parent node.

  Returns:

  True, if stop digging child and descendant properties.

  Type: boolean