Collection

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pentaho .lang.Collection

The Collection class is an abstract base class for typed, ordered maps.

Remarks

A collection is a list whose elements can only be contained in one position. If an attempt is made to add a duplicate element to the collection, an error is thrown.

Additionally, collection elements can be accessed by their key, and not only by position.

Elements of a collection must implement the pentaho.lang.ICollectionElement interface.

AMD Module

require(["pentaho/lang/Collection"], function(Collection) { /* code goes here */ });

Extends

pentaho.lang.List

Constructor

Name	Description
new Collection(keyArgs) Abstract	Initializes a collection instance.

Members

Name	Description
elemClass : `Class` Abstract	Gets the constructor function of the elements held by this collection.
length : `number`	The length of the list.
missingValue : `any`	Gets the value returned by `pentaho.lang.Collection#get` when an element with a given key is not contained in the collection.

Methods

Name	Description
_getElemName() : `string` Protected	Gets a common name for the elements held by this list.
add(elem, keyArgs) : `pentaho.lang.IListElement`	Appends an element to the list and returns it.
addMany(elems, keyArgs) : `number`	Appends elements to the list and returns its new length.
get(key, assertExists) : `pentaho.lang.ICollectionElement` \| `*`	Gets an element by its key.
getExisting(key) : `pentaho.lang.ICollectionElement`	Gets an existing element by its key.
has(key) : `boolean`	Tests if an element with a given key belongs to the collection.
includes(elem) : `boolean`	Checks if a given element belongs to the collection.
push(elems) : `number`	Appends elements to the list and returns its new length.
toSpec() : `Array`	Creates a specification of this list.

Constructor Details

new Collection(keyArgs)

Abstract

Initializes a collection instance.

Note that because a Collection is a sub-class of Array, the new operator cannot be used to create instances (at least up to ECMAScript version 5). Instead, instances of Collection are actually initial instances of Array whose prototype is then changed to be that of Collection. In other words, Collection is an "initialization" constructor (see pentaho.lang.ISpecifiable for more information on these concepts).

Concrete Collection sub-classes should provide a static to method to help in their construction.

Source: javascript/web/pentaho/lang/Collection.js, line 24

Parameters:
Name	Default Value	Summary
keyArgs : `Object` Optional		The keyword arguments. These are not used directly by the `Collection` class but are passed-through to the methods that handle the initialization of each list element.

Members Details

elemClass: `Class` Abstract
Gets the constructor function of the elements held by this collection. This class must implement the `pentaho.lang.ICollectionElement` interface. Source: javascript/web/pentaho/lang/Collection.js, line 87 Overrides: pentaho.lang.List#elemClass

elemClass: Class

Abstract

Gets the constructor function of the elements held by this collection.

This class must implement the pentaho.lang.ICollectionElement interface.

Source: javascript/web/pentaho/lang/Collection.js, line 87

Overrides: pentaho.lang.List#elemClass

length: `number`
The length of the list. Source: javascript/web/pentaho/lang/List.js, line 98 Inherited From: pentaho.lang.List#length

length: number

The length of the list.

Source: javascript/web/pentaho/lang/List.js, line 98

Inherited From: pentaho.lang.List#length

missingValue: `any`
Gets the value returned by `pentaho.lang.Collection#get` when an element with a given key is not contained in the collection. Source: javascript/web/pentaho/lang/Collection.js, line 85 Default Value: null

missingValue: any

Gets the value returned by pentaho.lang.Collection#get when an element with a given key is not contained in the collection.

Source: javascript/web/pentaho/lang/Collection.js, line 85

Default Value: null

Methods Details

_getElemName() : string

Protected

Gets a common name for the elements held by this list.

The default implementation returns the value of pentaho.lang.IListElement#elemName of pentaho.lang.List#elemClass.

Source: javascript/web/pentaho/lang/List.js, line 94

Inherited From: pentaho.lang.List#_getElemName

Returns:
Name	Description
`string`	The common name of the elements.

add(elem, keyArgs) : pentaho.lang.IListElement

Appends an element to the list and returns it.

The value specified in argument elem is converted to the list elements' class before actually being added to it.

Source: javascript/web/pentaho/lang/List.js, line 163

Inherited From: pentaho.lang.List#add

Parameters:
Name	Default Value	Summary
elem : `*`		An element or a value convertible to one.
keyArgs : `Object` Optional		The keyword arguments. These are not used directly by the `List` class but are passed-through to the methods that handle the initialization of list elements.

Returns:
Name	Description
`pentaho.lang.IListElement`	The added list element.

addMany(elems, keyArgs) : number

Appends elements to the list and returns its new length.

The values specified in elems are converted to the list elements' class before actually being added to it.

This method allows adding elements to the list using custom options (keyword arguments). Contrast with method pentaho.lang.List#push which adds elements using default options.

Source: javascript/web/pentaho/lang/List.js, line 144

Inherited From: pentaho.lang.List#addMany

Parameters:
Name	Default Value	Summary
elems : `Array`		An array of elements to add to the list.
keyArgs : `Object` Optional		The keyword arguments. These are not used directly by the `List` class but are passed-through to the methods that handle the initialization of each list element.

Returns:
Name	Description
`number`	The new length of the list.

get(key, assertExists) : pentaho.lang.ICollectionElement | *

Gets an element by its key.

Source: javascript/web/pentaho/lang/Collection.js, line 181

Parameters:
Name	Default Value	Summary
key : `string` Optional		The element's key.
assertExists : `boolean` Optional	false	Indicates if an error should be thrown when the collection does not contain an element with the given key.

Returns:
Name	Description
`pentaho.lang.ICollectionElement` \| `*`	The element with the given key, if one is contained by the collection, or `pentaho.lang.Collection#missingValue`, otherwise.

getExisting(key) : pentaho.lang.ICollectionElement

Gets an existing element by its key.

An error is thrown when the collection does not contain an element with the given key.

Source: javascript/web/pentaho/lang/Collection.js, line 204

Parameters:
Name	Default Value	Summary
key : `string` Optional		The element's key.

Returns:
Name	Description
`pentaho.lang.ICollectionElement`	The element with the given key.

See also: pentaho.lang.Collection#get

has(key) : boolean

Tests if an element with a given key belongs to the collection.

Source: javascript/web/pentaho/lang/Collection.js, line 161

Parameters:
Name	Default Value	Summary
key : `string` Optional		The element's key.

Returns:
Name	Description
`boolean`	`true` if an element with the given key belongs to the collection, `false` otherwise.

includes(elem) : boolean

Checks if a given element belongs to the collection.

Source: javascript/web/pentaho/lang/Collection.js, line 147

Parameters:
Name	Default Value	Summary
elem : `pentaho.lang.IWithKey` Optional		The element to check.

Returns:
Name	Description
`boolean`	`true` if the element is belongs to the collection, `false` otherwise.

push(elems) : number

Appends elements to the list and returns its new length.

The values specified in elems are converted to the list elements' class before actually being added to it.

This method adds elements to the list using default options. Use one of pentaho.lang.List#add or pentaho.lang.List#addMany to be able to specify non-default options (keyword arguments).

Source: javascript/web/pentaho/lang/List.js, line 121

Inherited From: pentaho.lang.List#push

Parameters:
Name	Default Value	Summary
elems : `*` Repeatable		The elements to add to the list.

Returns:
Name	Description
`number`	The new length of the list.

toSpec() : Array

Creates a specification of this list.

A list specification is an array containing the specifications of each of its elements.

If the element's class does not implement pentaho.lang.ISpecifiable, each element is assumed to be its own specification.

Source: javascript/web/pentaho/lang/List.js, line 249

Inherited From: pentaho.lang.List#toSpec

Returns:
Name	Description
`Array`	The list specification.