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922 lines
24 KiB
922 lines
24 KiB
var util = require('./util');
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var Queue = require('./Queue');
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/**
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* DataSet
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*
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* Usage:
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* var dataSet = new DataSet({
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* fieldId: '_id',
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* type: {
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* // ...
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* }
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* });
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*
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* dataSet.add(item);
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* dataSet.add(data);
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* dataSet.update(item);
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* dataSet.update(data);
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* dataSet.remove(id);
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* dataSet.remove(ids);
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* var data = dataSet.get();
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* var data = dataSet.get(id);
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* var data = dataSet.get(ids);
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* var data = dataSet.get(ids, options, data);
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* dataSet.clear();
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*
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* A data set can:
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* - add/remove/update data
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* - gives triggers upon changes in the data
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* - can import/export data in various data formats
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*
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* @param {Array} [data] Optional array with initial data
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* @param {Object} [options] Available options:
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* {String} fieldId Field name of the id in the
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* items, 'id' by default.
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* {Object.<String, String} type
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* A map with field names as key,
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* and the field type as value.
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* {Object} queue Queue changes to the DataSet,
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* flush them all at once.
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* Queue options:
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* - {number} delay Delay in ms, null by default
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* - {number} max Maximum number of entries in the queue, Infinity by default
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* @constructor DataSet
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*/
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// TODO: add a DataSet constructor DataSet(data, options)
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function DataSet (data, options) {
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// correctly read optional arguments
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if (data && !Array.isArray(data)) {
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options = data;
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data = null;
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}
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this._options = options || {};
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this._data = {}; // map with data indexed by id
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this.length = 0; // number of items in the DataSet
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this._fieldId = this._options.fieldId || 'id'; // name of the field containing id
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this._type = {}; // internal field types (NOTE: this can differ from this._options.type)
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// all variants of a Date are internally stored as Date, so we can convert
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// from everything to everything (also from ISODate to Number for example)
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if (this._options.type) {
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var fields = Object.keys(this._options.type);
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for (var i = 0, len = fields.length; i < len; i++) {
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var field = fields[i];
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var value = this._options.type[field];
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if (value == 'Date' || value == 'ISODate' || value == 'ASPDate') {
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this._type[field] = 'Date';
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}
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else {
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this._type[field] = value;
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}
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}
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}
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// TODO: deprecated since version 1.1.1 (or 2.0.0?)
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if (this._options.convert) {
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throw new Error('Option "convert" is deprecated. Use "type" instead.');
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}
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this._subscribers = {}; // event subscribers
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// add initial data when provided
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if (data) {
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this.add(data);
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}
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this.setOptions(options);
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}
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/**
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* @param {Object} [options] Available options:
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* {Object} queue Queue changes to the DataSet,
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* flush them all at once.
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* Queue options:
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* - {number} delay Delay in ms, null by default
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* - {number} max Maximum number of entries in the queue, Infinity by default
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* @param options
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*/
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DataSet.prototype.setOptions = function(options) {
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if (options && options.queue !== undefined) {
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if (options.queue === false) {
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// delete queue if loaded
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if (this._queue) {
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this._queue.destroy();
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delete this._queue;
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}
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}
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else {
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// create queue and update its options
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if (!this._queue) {
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this._queue = Queue.extend(this, {
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replace: ['add', 'update', 'remove']
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});
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}
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if (typeof options.queue === 'object') {
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this._queue.setOptions(options.queue);
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}
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}
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}
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};
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/**
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* Subscribe to an event, add an event listener
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* @param {String} event Event name. Available events: 'put', 'update',
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* 'remove'
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* @param {function} callback Callback method. Called with three parameters:
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* {String} event
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* {Object | null} params
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* {String | Number} senderId
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*/
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DataSet.prototype.on = function(event, callback) {
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var subscribers = this._subscribers[event];
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if (!subscribers) {
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subscribers = [];
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this._subscribers[event] = subscribers;
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}
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subscribers.push({
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callback: callback
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});
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};
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// TODO: remove this deprecated function some day (replaced with `on` since version 0.5, deprecated since v4.0)
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DataSet.prototype.subscribe = function () {
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throw new Error('DataSet.subscribe is deprecated. Use DataSet.on instead.');
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};
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/**
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* Unsubscribe from an event, remove an event listener
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* @param {String} event
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* @param {function} callback
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*/
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DataSet.prototype.off = function(event, callback) {
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var subscribers = this._subscribers[event];
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if (subscribers) {
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this._subscribers[event] = subscribers.filter(listener => listener.callback != callback);
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}
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};
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// TODO: remove this deprecated function some day (replaced with `on` since version 0.5, deprecated since v4.0)
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DataSet.prototype.unsubscribe = function () {
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throw new Error('DataSet.unsubscribe is deprecated. Use DataSet.off instead.');
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};
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/**
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* Trigger an event
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* @param {String} event
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* @param {Object | null} params
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* @param {String} [senderId] Optional id of the sender.
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* @private
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*/
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DataSet.prototype._trigger = function (event, params, senderId) {
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if (event == '*') {
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throw new Error('Cannot trigger event *');
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}
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var subscribers = [];
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if (event in this._subscribers) {
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subscribers = subscribers.concat(this._subscribers[event]);
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}
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if ('*' in this._subscribers) {
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subscribers = subscribers.concat(this._subscribers['*']);
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}
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for (var i = 0, len = subscribers.length; i < len; i++) {
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var subscriber = subscribers[i];
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if (subscriber.callback) {
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subscriber.callback(event, params, senderId || null);
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}
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}
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};
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/**
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* Add data.
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* Adding an item will fail when there already is an item with the same id.
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* @param {Object | Array} data
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* @param {String} [senderId] Optional sender id
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* @return {Array} addedIds Array with the ids of the added items
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*/
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DataSet.prototype.add = function (data, senderId) {
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var addedIds = [],
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id,
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me = this;
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if (Array.isArray(data)) {
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// Array
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for (var i = 0, len = data.length; i < len; i++) {
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id = me._addItem(data[i]);
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addedIds.push(id);
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}
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}
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else if (data instanceof Object) {
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// Single item
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id = me._addItem(data);
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addedIds.push(id);
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}
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else {
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throw new Error('Unknown dataType');
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}
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if (addedIds.length) {
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this._trigger('add', {items: addedIds}, senderId);
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}
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return addedIds;
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};
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/**
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* Update existing items. When an item does not exist, it will be created
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* @param {Object | Array} data
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* @param {String} [senderId] Optional sender id
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* @return {Array} updatedIds The ids of the added or updated items
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*/
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DataSet.prototype.update = function (data, senderId) {
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var addedIds = [];
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var updatedIds = [];
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var updatedData = [];
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var me = this;
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var fieldId = me._fieldId;
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var addOrUpdate = function (item) {
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var id = item[fieldId];
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if (me._data[id]) {
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var oldData = util.extend({}, me._data[id]);
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// update item
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id = me._updateItem(item);
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updatedIds.push(id);
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updatedData.push(oldData);
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}
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else {
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// add new item
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id = me._addItem(item);
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addedIds.push(id);
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}
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};
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if (Array.isArray(data)) {
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// Array
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for (var i = 0, len = data.length; i < len; i++) {
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addOrUpdate(data[i]);
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}
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}
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else if (data instanceof Object) {
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// Single item
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addOrUpdate(data);
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}
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else {
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throw new Error('Unknown dataType');
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}
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if (addedIds.length) {
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this._trigger('add', {items: addedIds}, senderId);
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}
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if (updatedIds.length) {
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this._trigger('update', {items: updatedIds, data: updatedData}, senderId);
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}
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return addedIds.concat(updatedIds);
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};
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/**
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* Get a data item or multiple items.
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*
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* Usage:
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*
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* get()
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* get(options: Object)
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*
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* get(id: Number | String)
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* get(id: Number | String, options: Object)
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*
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* get(ids: Number[] | String[])
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* get(ids: Number[] | String[], options: Object)
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*
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* Where:
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*
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* {Number | String} id The id of an item
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* {Number[] | String{}} ids An array with ids of items
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* {Object} options An Object with options. Available options:
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* {String} [returnType] Type of data to be returned.
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* Can be 'Array' (default) or 'Object'.
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* {Object.<String, String>} [type]
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* {String[]} [fields] field names to be returned
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* {function} [filter] filter items
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* {String | function} [order] Order the items by a field name or custom sort function.
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* @throws Error
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*/
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DataSet.prototype.get = function (args) {
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var me = this;
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// parse the arguments
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var id, ids, options;
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var firstType = util.getType(arguments[0]);
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if (firstType == 'String' || firstType == 'Number') {
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// get(id [, options])
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id = arguments[0];
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options = arguments[1];
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}
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else if (firstType == 'Array') {
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// get(ids [, options])
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ids = arguments[0];
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options = arguments[1];
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}
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else {
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// get([, options])
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options = arguments[0];
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}
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// determine the return type
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var returnType;
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if (options && options.returnType) {
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var allowedValues = ['Array', 'Object'];
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returnType = allowedValues.indexOf(options.returnType) == -1 ? 'Array' : options.returnType;
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}
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else {
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returnType = 'Array';
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}
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// build options
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var type = options && options.type || this._options.type;
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var filter = options && options.filter;
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var items = [], item, itemIds, itemId, i, len;
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// convert items
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if (id != undefined) {
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// return a single item
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item = me._getItem(id, type);
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if (filter && !filter(item)) {
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item = null;
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}
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}
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else if (ids != undefined) {
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// return a subset of items
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for (i = 0, len = ids.length; i < len; i++) {
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item = me._getItem(ids[i], type);
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if (!filter || filter(item)) {
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items.push(item);
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}
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}
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}
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else {
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// return all items
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itemIds = Object.keys(this._data);
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for (i = 0, len = itemIds.length; i < len; i++) {
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itemId = itemIds[i];
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item = me._getItem(itemId, type);
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if (!filter || filter(item)) {
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items.push(item);
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}
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}
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}
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// order the results
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if (options && options.order && id == undefined) {
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this._sort(items, options.order);
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}
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// filter fields of the items
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if (options && options.fields) {
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var fields = options.fields;
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if (id != undefined) {
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item = this._filterFields(item, fields);
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}
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else {
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for (i = 0, len = items.length; i < len; i++) {
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items[i] = this._filterFields(items[i], fields);
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}
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}
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}
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// return the results
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if (returnType == 'Object') {
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var result = {},
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resultant;
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for (i = 0, len = items.length; i < len; i++) {
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resultant = items[i];
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result[resultant.id] = resultant;
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}
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return result;
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}
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else {
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if (id != undefined) {
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// a single item
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return item;
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}
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else {
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// just return our array
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return items;
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}
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}
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};
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/**
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* Get ids of all items or from a filtered set of items.
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* @param {Object} [options] An Object with options. Available options:
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* {function} [filter] filter items
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* {String | function} [order] Order the items by
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* a field name or custom sort function.
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* @return {Array} ids
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*/
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DataSet.prototype.getIds = function (options) {
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var data = this._data,
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filter = options && options.filter,
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order = options && options.order,
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type = options && options.type || this._options.type,
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itemIds = Object.keys(data),
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i,
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len,
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id,
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item,
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items,
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ids = [];
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if (filter) {
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// get filtered items
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if (order) {
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// create ordered list
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items = [];
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for (i = 0, len = itemIds.length; i < len; i++) {
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id = itemIds[i];
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item = this._getItem(id, type);
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if (filter(item)) {
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items.push(item);
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}
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}
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this._sort(items, order);
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for (i = 0, len = items.length; i < len; i++) {
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ids.push(items[i][this._fieldId]);
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}
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}
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else {
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// create unordered list
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for (i = 0, len = itemIds.length; i < len; i++) {
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id = itemIds[i];
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item = this._getItem(id, type);
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if (filter(item)) {
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ids.push(item[this._fieldId]);
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}
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}
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}
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}
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else {
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// get all items
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if (order) {
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// create an ordered list
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items = [];
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for (i = 0, len = itemIds.length; i < len; i++) {
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id = itemIds[i];
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items.push(data[id]);
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}
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this._sort(items, order);
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for (i = 0, len = items.length; i < len; i++) {
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ids.push(items[i][this._fieldId]);
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}
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}
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else {
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// create unordered list
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for (i = 0, len = itemIds.length; i < len; i++) {
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id = itemIds[i];
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item = data[id];
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ids.push(item[this._fieldId]);
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}
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}
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}
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return ids;
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};
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/**
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* Returns the DataSet itself. Is overwritten for example by the DataView,
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* which returns the DataSet it is connected to instead.
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*/
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DataSet.prototype.getDataSet = function () {
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return this;
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};
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/**
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* Execute a callback function for every item in the dataset.
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* @param {function} callback
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* @param {Object} [options] Available options:
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* {Object.<String, String>} [type]
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* {String[]} [fields] filter fields
|
|
* {function} [filter] filter items
|
|
* {String | function} [order] Order the items by
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* a field name or custom sort function.
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*/
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DataSet.prototype.forEach = function (callback, options) {
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var filter = options && options.filter,
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type = options && options.type || this._options.type,
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data = this._data,
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itemIds = Object.keys(data),
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i,
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len,
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item,
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id;
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if (options && options.order) {
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// execute forEach on ordered list
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var items = this.get(options);
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for (i = 0, len = items.length; i < len; i++) {
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item = items[i];
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id = item[this._fieldId];
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callback(item, id);
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}
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}
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else {
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// unordered
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for (i = 0, len = itemIds.length; i < len; i++) {
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id = itemIds[i];
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item = this._getItem(id, type);
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if (!filter || filter(item)) {
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callback(item, id);
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}
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}
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}
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};
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/**
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* Map every item in the dataset.
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* @param {function} callback
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|
* @param {Object} [options] Available options:
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* {Object.<String, String>} [type]
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|
* {String[]} [fields] filter fields
|
|
* {function} [filter] filter items
|
|
* {String | function} [order] Order the items by
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|
* a field name or custom sort function.
|
|
* @return {Object[]} mappedItems
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*/
|
|
DataSet.prototype.map = function (callback, options) {
|
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var filter = options && options.filter,
|
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type = options && options.type || this._options.type,
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mappedItems = [],
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data = this._data,
|
|
itemIds = Object.keys(data),
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i,
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len,
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id,
|
|
item;
|
|
|
|
// convert and filter items
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
item = this._getItem(id, type);
|
|
if (!filter || filter(item)) {
|
|
mappedItems.push(callback(item, id));
|
|
}
|
|
}
|
|
|
|
// order items
|
|
if (options && options.order) {
|
|
this._sort(mappedItems, options.order);
|
|
}
|
|
|
|
return mappedItems;
|
|
};
|
|
|
|
/**
|
|
* Filter the fields of an item
|
|
* @param {Object | null} item
|
|
* @param {String[]} fields Field names
|
|
* @return {Object | null} filteredItem or null if no item is provided
|
|
* @private
|
|
*/
|
|
DataSet.prototype._filterFields = function (item, fields) {
|
|
if (!item) { // item is null
|
|
return item;
|
|
}
|
|
|
|
var filteredItem = {},
|
|
itemFields = Object.keys(item),
|
|
len = itemFields.length,
|
|
i,
|
|
field;
|
|
|
|
if(Array.isArray(fields)){
|
|
for (i = 0; i < len; i++) {
|
|
field = itemFields[i];
|
|
if (fields.indexOf(field) != -1) {
|
|
filteredItem[field] = item[field];
|
|
}
|
|
}
|
|
}else{
|
|
for (i = 0; i < len; i++) {
|
|
field = itemFields[i];
|
|
if (fields.hasOwnProperty(field)) {
|
|
filteredItem[fields[field]] = item[field];
|
|
}
|
|
}
|
|
}
|
|
|
|
return filteredItem;
|
|
};
|
|
|
|
/**
|
|
* Sort the provided array with items
|
|
* @param {Object[]} items
|
|
* @param {String | function} order A field name or custom sort function.
|
|
* @private
|
|
*/
|
|
DataSet.prototype._sort = function (items, order) {
|
|
if (util.isString(order)) {
|
|
// order by provided field name
|
|
var name = order; // field name
|
|
items.sort(function (a, b) {
|
|
var av = a[name];
|
|
var bv = b[name];
|
|
return (av > bv) ? 1 : ((av < bv) ? -1 : 0);
|
|
});
|
|
}
|
|
else if (typeof order === 'function') {
|
|
// order by sort function
|
|
items.sort(order);
|
|
}
|
|
// TODO: extend order by an Object {field:String, direction:String}
|
|
// where direction can be 'asc' or 'desc'
|
|
else {
|
|
throw new TypeError('Order must be a function or a string');
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Remove an object by pointer or by id
|
|
* @param {String | Number | Object | Array} id Object or id, or an array with
|
|
* objects or ids to be removed
|
|
* @param {String} [senderId] Optional sender id
|
|
* @return {Array} removedIds
|
|
*/
|
|
DataSet.prototype.remove = function (id, senderId) {
|
|
var removedIds = [],
|
|
i, len, removedId;
|
|
|
|
if (Array.isArray(id)) {
|
|
for (i = 0, len = id.length; i < len; i++) {
|
|
removedId = this._remove(id[i]);
|
|
if (removedId != null) {
|
|
removedIds.push(removedId);
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
removedId = this._remove(id);
|
|
if (removedId != null) {
|
|
removedIds.push(removedId);
|
|
}
|
|
}
|
|
|
|
if (removedIds.length) {
|
|
this._trigger('remove', {items: removedIds}, senderId);
|
|
}
|
|
|
|
return removedIds;
|
|
};
|
|
|
|
/**
|
|
* Remove an item by its id
|
|
* @param {Number | String | Object} id id or item
|
|
* @returns {Number | String | null} id
|
|
* @private
|
|
*/
|
|
DataSet.prototype._remove = function (id) {
|
|
if (util.isNumber(id) || util.isString(id)) {
|
|
if (this._data[id]) {
|
|
delete this._data[id];
|
|
this.length--;
|
|
return id;
|
|
}
|
|
}
|
|
else if (id instanceof Object) {
|
|
var itemId = id[this._fieldId];
|
|
if (itemId && this._data[itemId]) {
|
|
delete this._data[itemId];
|
|
this.length--;
|
|
return itemId;
|
|
}
|
|
}
|
|
return null;
|
|
};
|
|
|
|
/**
|
|
* Clear the data
|
|
* @param {String} [senderId] Optional sender id
|
|
* @return {Array} removedIds The ids of all removed items
|
|
*/
|
|
DataSet.prototype.clear = function (senderId) {
|
|
var ids = Object.keys(this._data);
|
|
|
|
this._data = {};
|
|
this.length = 0;
|
|
|
|
this._trigger('remove', {items: ids}, senderId);
|
|
|
|
return ids;
|
|
};
|
|
|
|
/**
|
|
* Find the item with maximum value of a specified field
|
|
* @param {String} field
|
|
* @return {Object | null} item Item containing max value, or null if no items
|
|
*/
|
|
DataSet.prototype.max = function (field) {
|
|
var data = this._data,
|
|
itemIds = Object.keys(data),
|
|
max = null,
|
|
maxField = null,
|
|
i,
|
|
len;
|
|
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
var id = itemIds[i];
|
|
var item = data[id];
|
|
var itemField = item[field];
|
|
if (itemField != null && (!max || itemField > maxField)) {
|
|
max = item;
|
|
maxField = itemField;
|
|
}
|
|
}
|
|
|
|
return max;
|
|
};
|
|
|
|
/**
|
|
* Find the item with minimum value of a specified field
|
|
* @param {String} field
|
|
* @return {Object | null} item Item containing max value, or null if no items
|
|
*/
|
|
DataSet.prototype.min = function (field) {
|
|
var data = this._data,
|
|
itemIds = Object.keys(data),
|
|
min = null,
|
|
minField = null,
|
|
i,
|
|
len;
|
|
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
var id = itemIds[i];
|
|
var item = data[id];
|
|
var itemField = item[field];
|
|
if (itemField != null && (!min || itemField < minField)) {
|
|
min = item;
|
|
minField = itemField;
|
|
}
|
|
}
|
|
|
|
return min;
|
|
};
|
|
|
|
/**
|
|
* Find all distinct values of a specified field
|
|
* @param {String} field
|
|
* @return {Array} values Array containing all distinct values. If data items
|
|
* do not contain the specified field are ignored.
|
|
* The returned array is unordered.
|
|
*/
|
|
DataSet.prototype.distinct = function (field) {
|
|
var data = this._data;
|
|
var itemIds = Object.keys(data);
|
|
var values = [];
|
|
var fieldType = this._options.type && this._options.type[field] || null;
|
|
var count = 0;
|
|
var i,
|
|
j,
|
|
len;
|
|
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
var id = itemIds[i];
|
|
var item = data[id];
|
|
var value = item[field];
|
|
var exists = false;
|
|
for (j = 0; j < count; j++) {
|
|
if (values[j] == value) {
|
|
exists = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!exists && (value !== undefined)) {
|
|
values[count] = value;
|
|
count++;
|
|
}
|
|
}
|
|
|
|
if (fieldType) {
|
|
for (i = 0, len = values.length; i < len; i++) {
|
|
values[i] = util.convert(values[i], fieldType);
|
|
}
|
|
}
|
|
|
|
return values;
|
|
};
|
|
|
|
/**
|
|
* Add a single item. Will fail when an item with the same id already exists.
|
|
* @param {Object} item
|
|
* @return {String} id
|
|
* @private
|
|
*/
|
|
DataSet.prototype._addItem = function (item) {
|
|
var id = item[this._fieldId];
|
|
|
|
if (id != undefined) {
|
|
// check whether this id is already taken
|
|
if (this._data[id]) {
|
|
// item already exists
|
|
throw new Error('Cannot add item: item with id ' + id + ' already exists');
|
|
}
|
|
}
|
|
else {
|
|
// generate an id
|
|
id = util.randomUUID();
|
|
item[this._fieldId] = id;
|
|
}
|
|
|
|
var d = {},
|
|
fields = Object.keys(item),
|
|
i,
|
|
len;
|
|
for (i = 0, len = fields.length; i < len; i++) {
|
|
var field = fields[i];
|
|
var fieldType = this._type[field]; // type may be undefined
|
|
d[field] = util.convert(item[field], fieldType);
|
|
}
|
|
this._data[id] = d;
|
|
this.length++;
|
|
|
|
return id;
|
|
};
|
|
|
|
/**
|
|
* Get an item. Fields can be converted to a specific type
|
|
* @param {String} id
|
|
* @param {Object.<String, String>} [types] field types to convert
|
|
* @return {Object | null} item
|
|
* @private
|
|
*/
|
|
DataSet.prototype._getItem = function (id, types) {
|
|
var field, value, i, len;
|
|
|
|
// get the item from the dataset
|
|
var raw = this._data[id];
|
|
if (!raw) {
|
|
return null;
|
|
}
|
|
|
|
// convert the items field types
|
|
var converted = {},
|
|
fields = Object.keys(raw);
|
|
|
|
if (types) {
|
|
for (i = 0, len = fields.length; i < len; i++) {
|
|
field = fields[i];
|
|
value = raw[field];
|
|
converted[field] = util.convert(value, types[field]);
|
|
}
|
|
}
|
|
else {
|
|
// no field types specified, no converting needed
|
|
for (i = 0, len = fields.length; i < len; i++) {
|
|
field = fields[i];
|
|
value = raw[field];
|
|
converted[field] = value;
|
|
}
|
|
}
|
|
return converted;
|
|
};
|
|
|
|
/**
|
|
* Update a single item: merge with existing item.
|
|
* Will fail when the item has no id, or when there does not exist an item
|
|
* with the same id.
|
|
* @param {Object} item
|
|
* @return {String} id
|
|
* @private
|
|
*/
|
|
DataSet.prototype._updateItem = function (item) {
|
|
var id = item[this._fieldId];
|
|
if (id == undefined) {
|
|
throw new Error('Cannot update item: item has no id (item: ' + JSON.stringify(item) + ')');
|
|
}
|
|
var d = this._data[id];
|
|
if (!d) {
|
|
// item doesn't exist
|
|
throw new Error('Cannot update item: no item with id ' + id + ' found');
|
|
}
|
|
|
|
// merge with current item
|
|
var fields = Object.keys(item);
|
|
for (var i = 0, len = fields.length; i < len; i++) {
|
|
var field = fields[i];
|
|
var fieldType = this._type[field]; // type may be undefined
|
|
d[field] = util.convert(item[field], fieldType);
|
|
}
|
|
|
|
return id;
|
|
};
|
|
|
|
module.exports = DataSet;
|