File: //home/arjun/projects/buyercall/node_modules/@ckeditor/ckeditor5-utils/src/collection.js
/**
* @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
*/
/**
* @module utils/collection
*/
import EmitterMixin from './emittermixin';
import CKEditorError from './ckeditorerror';
import uid from './uid';
import isIterable from './isiterable';
import mix from './mix';
/**
* Collections are ordered sets of objects. Items in the collection can be retrieved by their indexes
* in the collection (like in an array) or by their ids.
*
* If an object without an `id` property is being added to the collection, the `id` property will be generated
* automatically. Note that the automatically generated id is unique only within this single collection instance.
*
* By default an item in the collection is identified by its `id` property. The name of the identifier can be
* configured through the constructor of the collection.
*
* @mixes module:utils/emittermixin~EmitterMixin
*/
export default class Collection {
/**
* Creates a new Collection instance.
*
* You can provide an iterable of initial items the collection will be created with:
*
* const collection = new Collection( [ { id: 'John' }, { id: 'Mike' } ] );
*
* console.log( collection.get( 0 ) ); // -> { id: 'John' }
* console.log( collection.get( 1 ) ); // -> { id: 'Mike' }
* console.log( collection.get( 'Mike' ) ); // -> { id: 'Mike' }
*
* Or you can first create a collection and then add new items using the {@link #add} method:
*
* const collection = new Collection();
*
* collection.add( { id: 'John' } );
* console.log( collection.get( 0 ) ); // -> { id: 'John' }
*
* Whatever option you choose, you can always pass a configuration object as the last argument
* of the constructor:
*
* const emptyCollection = new Collection( { idProperty: 'name' } );
* emptyCollection.add( { name: 'John' } );
* console.log( collection.get( 'John' ) ); // -> { name: 'John' }
*
* const nonEmptyCollection = new Collection( [ { name: 'John' } ], { idProperty: 'name' } );
* nonEmptyCollection.add( { name: 'George' } );
* console.log( collection.get( 'George' ) ); // -> { name: 'George' }
* console.log( collection.get( 'John' ) ); // -> { name: 'John' }
*
* @param {Iterable.<Object>|Object} [initialItemsOrOptions] The initial items of the collection or
* the options object.
* @param {Object} [options={}] The options object, when the first argument is an array of initial items.
* @param {String} [options.idProperty='id'] The name of the property which is used to identify an item.
* Items that do not have such a property will be assigned one when added to the collection.
*/
constructor( initialItemsOrOptions = {}, options = {} ) {
const hasInitialItems = isIterable( initialItemsOrOptions );
if ( !hasInitialItems ) {
options = initialItemsOrOptions;
}
/**
* The internal list of items in the collection.
*
* @private
* @member {Object[]}
*/
this._items = [];
/**
* The internal map of items in the collection.
*
* @private
* @member {Map}
*/
this._itemMap = new Map();
/**
* The name of the property which is considered to identify an item.
*
* @private
* @member {String}
*/
this._idProperty = options.idProperty || 'id';
/**
* A helper mapping external items of a bound collection ({@link #bindTo})
* and actual items of this collection. It provides information
* necessary to properly remove items bound to another collection.
*
* See {@link #_bindToInternalToExternalMap}.
*
* @protected
* @member {WeakMap}
*/
this._bindToExternalToInternalMap = new WeakMap();
/**
* A helper mapping items of this collection to external items of a bound collection
* ({@link #bindTo}). It provides information necessary to manage the bindings, e.g.
* to avoid loops in two–way bindings.
*
* See {@link #_bindToExternalToInternalMap}.
*
* @protected
* @member {WeakMap}
*/
this._bindToInternalToExternalMap = new WeakMap();
/**
* Stores indexes of skipped items from bound external collection.
*
* @private
* @member {Array}
*/
this._skippedIndexesFromExternal = [];
// Set the initial content of the collection (if provided in the constructor).
if ( hasInitialItems ) {
for ( const item of initialItemsOrOptions ) {
this._items.push( item );
this._itemMap.set( this._getItemIdBeforeAdding( item ), item );
}
}
/**
* A collection instance this collection is bound to as a result
* of calling {@link #bindTo} method.
*
* @protected
* @member {module:utils/collection~Collection} #_bindToCollection
*/
}
/**
* The number of items available in the collection.
*
* @member {Number} #length
*/
get length() {
return this._items.length;
}
/**
* Returns the first item from the collection or null when collection is empty.
*
* @returns {Object|null} The first item or `null` if collection is empty.
*/
get first() {
return this._items[ 0 ] || null;
}
/**
* Returns the last item from the collection or null when collection is empty.
*
* @returns {Object|null} The last item or `null` if collection is empty.
*/
get last() {
return this._items[ this.length - 1 ] || null;
}
/**
* Adds an item into the collection.
*
* If the item does not have an id, then it will be automatically generated and set on the item.
*
* @chainable
* @param {Object} item
* @param {Number} [index] The position of the item in the collection. The item
* is pushed to the collection when `index` not specified.
* @fires add
* @fires change
*/
add( item, index ) {
return this.addMany( [ item ], index );
}
/**
* Adds multiple items into the collection.
*
* Any item not containing an id will get an automatically generated one.
*
* @chainable
* @param {Iterable.<Object>} item
* @param {Number} [index] The position of the insertion. Items will be appended if no `index` is specified.
* @fires add
* @fires change
*/
addMany( items, index ) {
if ( index === undefined ) {
index = this._items.length;
} else if ( index > this._items.length || index < 0 ) {
/**
* The `index` passed to {@link module:utils/collection~Collection#addMany `Collection#addMany()`}
* is invalid. It must be a number between 0 and the collection's length.
*
* @error collection-add-item-invalid-index
*/
throw new CKEditorError( 'collection-add-item-invalid-index', this );
}
for ( let offset = 0; offset < items.length; offset++ ) {
const item = items[ offset ];
const itemId = this._getItemIdBeforeAdding( item );
const currentItemIndex = index + offset;
this._items.splice( currentItemIndex, 0, item );
this._itemMap.set( itemId, item );
this.fire( 'add', item, currentItemIndex );
}
this.fire( 'change', {
added: items,
removed: [],
index
} );
return this;
}
/**
* Gets an item by its ID or index.
*
* @param {String|Number} idOrIndex The item ID or index in the collection.
* @returns {Object|null} The requested item or `null` if such item does not exist.
*/
get( idOrIndex ) {
let item;
if ( typeof idOrIndex == 'string' ) {
item = this._itemMap.get( idOrIndex );
} else if ( typeof idOrIndex == 'number' ) {
item = this._items[ idOrIndex ];
} else {
/**
* An index or ID must be given.
*
* @error collection-get-invalid-arg
*/
throw new CKEditorError( 'collection-get-invalid-arg', this );
}
return item || null;
}
/**
* Returns a Boolean indicating whether the collection contains an item.
*
* @param {Object|String} itemOrId The item or its ID in the collection.
* @returns {Boolean} `true` if the collection contains the item, `false` otherwise.
*/
has( itemOrId ) {
if ( typeof itemOrId == 'string' ) {
return this._itemMap.has( itemOrId );
} else { // Object
const idProperty = this._idProperty;
const id = itemOrId[ idProperty ];
return this._itemMap.has( id );
}
}
/**
* Gets an index of an item in the collection.
* When an item is not defined in the collection, the index will equal -1.
*
* @param {Object|String} itemOrId The item or its ID in the collection.
* @returns {Number} The index of a given item.
*/
getIndex( itemOrId ) {
let item;
if ( typeof itemOrId == 'string' ) {
item = this._itemMap.get( itemOrId );
} else {
item = itemOrId;
}
return this._items.indexOf( item );
}
/**
* Removes an item from the collection.
*
* @param {Object|Number|String} subject The item to remove, its ID or index in the collection.
* @returns {Object} The removed item.
* @fires remove
* @fires change
*/
remove( subject ) {
const [ item, index ] = this._remove( subject );
this.fire( 'change', {
added: [],
removed: [ item ],
index
} );
return item;
}
/**
* Executes the callback for each item in the collection and composes an array or values returned by this callback.
*
* @param {Function} callback
* @param {Object} callback.item
* @param {Number} callback.index
* @param {Object} ctx Context in which the `callback` will be called.
* @returns {Array} The result of mapping.
*/
map( callback, ctx ) {
return this._items.map( callback, ctx );
}
/**
* Finds the first item in the collection for which the `callback` returns a true value.
*
* @param {Function} callback
* @param {Object} callback.item
* @param {Number} callback.index
* @param {Object} ctx Context in which the `callback` will be called.
* @returns {Object} The item for which `callback` returned a true value.
*/
find( callback, ctx ) {
return this._items.find( callback, ctx );
}
/**
* Returns an array with items for which the `callback` returned a true value.
*
* @param {Function} callback
* @param {Object} callback.item
* @param {Number} callback.index
* @param {Object} ctx Context in which the `callback` will be called.
* @returns {Object[]} The array with matching items.
*/
filter( callback, ctx ) {
return this._items.filter( callback, ctx );
}
/**
* Removes all items from the collection and destroys the binding created using
* {@link #bindTo}.
*
* @fires remove
* @fires change
*/
clear() {
if ( this._bindToCollection ) {
this.stopListening( this._bindToCollection );
this._bindToCollection = null;
}
const removedItems = Array.from( this._items );
while ( this.length ) {
this._remove( 0 );
}
this.fire( 'change', {
added: [],
removed: removedItems,
index: 0
} );
}
/**
* Binds and synchronizes the collection with another one.
*
* The binding can be a simple factory:
*
* class FactoryClass {
* constructor( data ) {
* this.label = data.label;
* }
* }
*
* const source = new Collection( { idProperty: 'label' } );
* const target = new Collection();
*
* target.bindTo( source ).as( FactoryClass );
*
* source.add( { label: 'foo' } );
* source.add( { label: 'bar' } );
*
* console.log( target.length ); // 2
* console.log( target.get( 1 ).label ); // 'bar'
*
* source.remove( 0 );
* console.log( target.length ); // 1
* console.log( target.get( 0 ).label ); // 'bar'
*
* or the factory driven by a custom callback:
*
* class FooClass {
* constructor( data ) {
* this.label = data.label;
* }
* }
*
* class BarClass {
* constructor( data ) {
* this.label = data.label;
* }
* }
*
* const source = new Collection( { idProperty: 'label' } );
* const target = new Collection();
*
* target.bindTo( source ).using( ( item ) => {
* if ( item.label == 'foo' ) {
* return new FooClass( item );
* } else {
* return new BarClass( item );
* }
* } );
*
* source.add( { label: 'foo' } );
* source.add( { label: 'bar' } );
*
* console.log( target.length ); // 2
* console.log( target.get( 0 ) instanceof FooClass ); // true
* console.log( target.get( 1 ) instanceof BarClass ); // true
*
* or the factory out of property name:
*
* const source = new Collection( { idProperty: 'label' } );
* const target = new Collection();
*
* target.bindTo( source ).using( 'label' );
*
* source.add( { label: { value: 'foo' } } );
* source.add( { label: { value: 'bar' } } );
*
* console.log( target.length ); // 2
* console.log( target.get( 0 ).value ); // 'foo'
* console.log( target.get( 1 ).value ); // 'bar'
*
* It's possible to skip specified items by returning falsy value:
*
* const source = new Collection();
* const target = new Collection();
*
* target.bindTo( source ).using( item => {
* if ( item.hidden ) {
* return null;
* }
*
* return item;
* } );
*
* source.add( { hidden: true } );
* source.add( { hidden: false } );
*
* console.log( source.length ); // 2
* console.log( target.length ); // 1
*
* **Note**: {@link #clear} can be used to break the binding.
*
* @param {module:utils/collection~Collection} externalCollection A collection to be bound.
* @returns {Object}
* @returns {module:utils/collection~CollectionBindToChain} The binding chain object.
*/
bindTo( externalCollection ) {
if ( this._bindToCollection ) {
/**
* The collection cannot be bound more than once.
*
* @error collection-bind-to-rebind
*/
throw new CKEditorError( 'collection-bind-to-rebind', this );
}
this._bindToCollection = externalCollection;
return {
as: Class => {
this._setUpBindToBinding( item => new Class( item ) );
},
using: callbackOrProperty => {
if ( typeof callbackOrProperty == 'function' ) {
this._setUpBindToBinding( item => callbackOrProperty( item ) );
} else {
this._setUpBindToBinding( item => item[ callbackOrProperty ] );
}
}
};
}
/**
* Finalizes and activates a binding initiated by {#bindTo}.
*
* @protected
* @param {Function} factory A function which produces collection items.
*/
_setUpBindToBinding( factory ) {
const externalCollection = this._bindToCollection;
// Adds the item to the collection once a change has been done to the external collection.
//
// @private
const addItem = ( evt, externalItem, index ) => {
const isExternalBoundToThis = externalCollection._bindToCollection == this;
const externalItemBound = externalCollection._bindToInternalToExternalMap.get( externalItem );
// If an external collection is bound to this collection, which makes it a 2–way binding,
// and the particular external collection item is already bound, don't add it here.
// The external item has been created **out of this collection's item** and (re)adding it will
// cause a loop.
if ( isExternalBoundToThis && externalItemBound ) {
this._bindToExternalToInternalMap.set( externalItem, externalItemBound );
this._bindToInternalToExternalMap.set( externalItemBound, externalItem );
} else {
const item = factory( externalItem );
// When there is no item we need to remember skipped index first and then we can skip this item.
if ( !item ) {
this._skippedIndexesFromExternal.push( index );
return;
}
// Lets try to put item at the same index as index in external collection
// but when there are a skipped items in one or both collections we need to recalculate this index.
let finalIndex = index;
// When we try to insert item after some skipped items from external collection we need
// to include this skipped items and decrease index.
//
// For the following example:
// external -> [ 'A', 'B - skipped for internal', 'C - skipped for internal' ]
// internal -> [ A ]
//
// Another item is been added at the end of external collection:
// external.add( 'D' )
// external -> [ 'A', 'B - skipped for internal', 'C - skipped for internal', 'D' ]
//
// We can't just add 'D' to internal at the same index as index in external because
// this will produce empty indexes what is invalid:
// internal -> [ 'A', empty, empty, 'D' ]
//
// So we need to include skipped items and decrease index
// internal -> [ 'A', 'D' ]
for ( const skipped of this._skippedIndexesFromExternal ) {
if ( index > skipped ) {
finalIndex--;
}
}
// We need to take into consideration that external collection could skip some items from
// internal collection.
//
// For the following example:
// internal -> [ 'A', 'B - skipped for external', 'C - skipped for external' ]
// external -> [ A ]
//
// Another item is been added at the end of external collection:
// external.add( 'D' )
// external -> [ 'A', 'D' ]
//
// We need to include skipped items and place new item after them:
// internal -> [ 'A', 'B - skipped for external', 'C - skipped for external', 'D' ]
for ( const skipped of externalCollection._skippedIndexesFromExternal ) {
if ( finalIndex >= skipped ) {
finalIndex++;
}
}
this._bindToExternalToInternalMap.set( externalItem, item );
this._bindToInternalToExternalMap.set( item, externalItem );
this.add( item, finalIndex );
// After adding new element to internal collection we need update indexes
// of skipped items in external collection.
for ( let i = 0; i < externalCollection._skippedIndexesFromExternal.length; i++ ) {
if ( finalIndex <= externalCollection._skippedIndexesFromExternal[ i ] ) {
externalCollection._skippedIndexesFromExternal[ i ]++;
}
}
}
};
// Load the initial content of the collection.
for ( const externalItem of externalCollection ) {
addItem( null, externalItem, externalCollection.getIndex( externalItem ) );
}
// Synchronize the with collection as new items are added.
this.listenTo( externalCollection, 'add', addItem );
// Synchronize the with collection as new items are removed.
this.listenTo( externalCollection, 'remove', ( evt, externalItem, index ) => {
const item = this._bindToExternalToInternalMap.get( externalItem );
if ( item ) {
this.remove( item );
}
// After removing element from external collection we need update/remove indexes
// of skipped items in internal collection.
this._skippedIndexesFromExternal = this._skippedIndexesFromExternal.reduce( ( result, skipped ) => {
if ( index < skipped ) {
result.push( skipped - 1 );
}
if ( index > skipped ) {
result.push( skipped );
}
return result;
}, [] );
} );
}
/**
* Returns an unique id property for a given `item`.
*
* The method will generate new id and assign it to the `item` if it doesn't have any.
*
* @private
* @param {Object} item Item to be added.
* @returns {String}
*/
_getItemIdBeforeAdding( item ) {
const idProperty = this._idProperty;
let itemId;
if ( ( idProperty in item ) ) {
itemId = item[ idProperty ];
if ( typeof itemId != 'string' ) {
/**
* This item's ID should be a string.
*
* @error collection-add-invalid-id
*/
throw new CKEditorError( 'collection-add-invalid-id', this );
}
if ( this.get( itemId ) ) {
/**
* This item already exists in the collection.
*
* @error collection-add-item-already-exists
*/
throw new CKEditorError( 'collection-add-item-already-exists', this );
}
} else {
item[ idProperty ] = itemId = uid();
}
return itemId;
}
/**
* Core {@link #remove} method implementation shared in other functions.
*
* In contrast this method **does not** fire the {@link #event:change} event.
*
* @private
* @param {Object} subject The item to remove, its id or index in the collection.
* @returns {Array} Returns an array with the removed item and its index.
* @fires remove
*/
_remove( subject ) {
let index, id, item;
let itemDoesNotExist = false;
const idProperty = this._idProperty;
if ( typeof subject == 'string' ) {
id = subject;
item = this._itemMap.get( id );
itemDoesNotExist = !item;
if ( item ) {
index = this._items.indexOf( item );
}
} else if ( typeof subject == 'number' ) {
index = subject;
item = this._items[ index ];
itemDoesNotExist = !item;
if ( item ) {
id = item[ idProperty ];
}
} else {
item = subject;
id = item[ idProperty ];
index = this._items.indexOf( item );
itemDoesNotExist = ( index == -1 || !this._itemMap.get( id ) );
}
if ( itemDoesNotExist ) {
/**
* Item not found.
*
* @error collection-remove-404
*/
throw new CKEditorError( 'collection-remove-404', this );
}
this._items.splice( index, 1 );
this._itemMap.delete( id );
const externalItem = this._bindToInternalToExternalMap.get( item );
this._bindToInternalToExternalMap.delete( item );
this._bindToExternalToInternalMap.delete( externalItem );
this.fire( 'remove', item, index );
return [ item, index ];
}
/**
* Iterable interface.
*
* @returns {Iterable.<*>}
*/
[ Symbol.iterator ]() {
return this._items[ Symbol.iterator ]();
}
/**
* Fired when an item is added to the collection.
*
* @event add
* @param {Object} item The added item.
*/
/**
* Fired when the collection was changed due to adding or removing items.
*
* @event change
* @param {Iterable.<Object>} added A list of added items.
* @param {Iterable.<Object>} removed A list of removed items.
* @param {Number} index An index where the addition or removal occurred.
*/
/**
* Fired when an item is removed from the collection.
*
* @event remove
* @param {Object} item The removed item.
* @param {Number} index Index from which item was removed.
*/
}
mix( Collection, EmitterMixin );
/**
* An object returned by the {@link module:utils/collection~Collection#bindTo `bindTo()`} method
* providing functions that specify the type of the binding.
*
* See the {@link module:utils/collection~Collection#bindTo `bindTo()`} documentation for examples.
*
* @interface module:utils/collection~CollectionBindToChain
*/
/**
* Creates a callback or a property binding.
*
* @method #using
* @param {Function|String} callbackOrProperty When the function is passed, it should return
* the collection items. When the string is provided, the property value is used to create the bound collection items.
*/
/**
* Creates the class factory binding in which items of the source collection are passed to
* the constructor of the specified class.
*
* @method #as
* @param {Function} Class The class constructor used to create instances in the factory.
*/