# Class: Class

## LuCI. Class

`LuCI.Class` is the abstract base class all LuCI classes inherit from.

It provides simple means to create subclasses of given classes and implements prototypal inheritance.

#### new LuCI.Class()

luci.js, line 59

### Methods

#### staticLuCI.Class.extend(properties){LuCI.Class}

luci.js, line 87

  Extends this base class with the properties described in `properties` and returns a new subclassed Class instance

  Name | Type | Description
  --- | --- | ---
  `properties` | Object.<string, *> | An object describing the properties to add to the new subclass.

  ##### Returns:

  Type | Description
  --- | ---
  LuCI.Class | Returns a new LuCI.Class sublassed from this class, extended by the given properties and with its prototype set to this base class to enable inheritance. The resulting value represents a class constructor and can be instantiated with `new`.

#### staticLuCI.Class.instantiate(params, new_args){LuCI.Class}

luci.js, line 169

  Calls the class constructor using `new` with the given argument array being passed as variadic parameters to the constructor.

  Name | Type | Description
  --- | --- | ---
  `params` | Array.<*> | An array of arbitrary values which will be passed as arguments to the constructor function.
  `new_args` | * | optional repeatable Specifies arguments to be passed to the subclass constructor as-is in order to instantiate the new subclass.

  ##### Returns:

  Type | Description
  --- | ---
  LuCI.Class | Returns a new LuCI.Class instance extended by the given properties with its prototype set to this base class to enable inheritance.

#### staticLuCI.Class.isSubclass(classValue){boolean}

luci.js, line 195

  Checks whether the given class value is a subclass of this class.

  Name | Type | Description
  --- | --- | ---
  `classValue` | LuCI.Class | The class object to test.

  ##### Returns:

  Type | Description
  --- | ---
  boolean | Returns `true` when the given `classValue` is a subclass of this class or `false` if the given value is not a valid class or not a subclass of this class'.

#### staticLuCI.Class.singleton(properties, new_args){LuCI.Class}

luci.js, line 145

  Extends this base class with the properties described in `properties`, instantiates the resulting subclass using the additional optional arguments passed to this function and returns the resulting subclassed Class instance.

  This function serves as a convenience shortcut for `Class.extend()` and subsequent `new`.

  Name | Type | Description
  --- | --- | ---
  `properties` | Object.<string, *> | An object describing the properties to add to the new subclass.
  `new_args` | * | optional repeatable Specifies arguments to be passed to the subclass constructor as-is in order to instantiate the new subclass.

  ##### Returns:

  Type | Description
  --- | ---
  LuCI.Class | Returns a new LuCI.Class instance extended by the given properties with its prototype set to this base class to enable inheritance.

#### super(key, callArgs){*|null}

luci.js, line 267

  Walks up the parent class chain and looks for a class member called `key` in any of the parent classes this class inherits from. Returns the member value of the superclass or calls the member as function and returns its return value when the optional `callArgs` array is given.

  This function has two signatures and is sensitive to the amount of arguments passed to it:

  - `super('key')` - Returns the value of `key` when found within one of the parent classes.
  - `super('key', ['arg1', 'arg2'])` - Calls the `key()` method with parameters `arg1` and `arg2` when found within one of the parent classes.

  Name | Type | Description
  --- | --- | ---
  `key` | string | The name of the superclass member to retrieve.
  `callArgs` | Array.<*> | optional An optional array of function call parameters to use. When this parameter is specified, the found member value is called as function using the values of this array as arguments.

  ##### Throws:

  Throws a `ReferenceError` when `callArgs` are specified and the found member named by `key` is not a function value.

  Type
    ReferenceError

  ##### Returns:

  Type | Description
  --- | ---
  * | null | Returns the value of the found member or the return value of the call to the found method. Returns `null` when no member was found in the parent class chain or when the call to the superclass method returned `null`.

#### varargs(args, offset, extra_args){Array.<*>}

luci.js, line 225

  Extract all values from the given argument array beginning from `offset` and prepend any further given optional parameters to the beginning of the resulting array copy.

  Name | Type | Description
  --- | --- | ---
  `args` | Array.<*> | The array to extract the values from.
  `offset` | number | The offset from which to extract the values. An offset of `0` would copy all values till the end.
  `extra_args` | * | optional repeatable Extra arguments to add to prepend to the resultung array.

  ##### Returns:

  Type | Description
  --- | ---
  Array.<*> | Returns a new array consisting of the optional extra arguments and the values extracted from the `args` array beginning with `offset`.