You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
939 lines
25 KiB
939 lines
25 KiB
var util = require('./util');
|
|
var Queue = require('./Queue');
|
|
|
|
/**
|
|
* DataSet
|
|
* // TODO: add a DataSet constructor DataSet(data, options)
|
|
*
|
|
* Usage:
|
|
* var dataSet = new DataSet({
|
|
* fieldId: '_id',
|
|
* type: {
|
|
* // ...
|
|
* }
|
|
* });
|
|
*
|
|
* dataSet.add(item);
|
|
* dataSet.add(data);
|
|
* dataSet.update(item);
|
|
* dataSet.update(data);
|
|
* dataSet.remove(id);
|
|
* dataSet.remove(ids);
|
|
* var data = dataSet.get();
|
|
* var data = dataSet.get(id);
|
|
* var data = dataSet.get(ids);
|
|
* var data = dataSet.get(ids, options, data);
|
|
* dataSet.clear();
|
|
*
|
|
* A data set can:
|
|
* - add/remove/update data
|
|
* - gives triggers upon changes in the data
|
|
* - can import/export data in various data formats
|
|
*
|
|
* @param {Array} [data] Optional array with initial data
|
|
* @param {Object} [options] Available options:
|
|
* {string} fieldId Field name of the id in the
|
|
* items, 'id' by default.
|
|
* {Object.<string, string} type
|
|
* A map with field names as key,
|
|
* and the field type as value.
|
|
* {Object} queue Queue changes to the DataSet,
|
|
* flush them all at once.
|
|
* Queue options:
|
|
* - {number} delay Delay in ms, null by default
|
|
* - {number} max Maximum number of entries in the queue, Infinity by default
|
|
* @constructor DataSet
|
|
*/
|
|
function DataSet (data, options) {
|
|
// correctly read optional arguments
|
|
if (data && !Array.isArray(data)) {
|
|
options = data;
|
|
data = null;
|
|
}
|
|
|
|
this._options = options || {};
|
|
this._data = {}; // map with data indexed by id
|
|
this.length = 0; // number of items in the DataSet
|
|
this._fieldId = this._options.fieldId || 'id'; // name of the field containing id
|
|
this._type = {}; // internal field types (NOTE: this can differ from this._options.type)
|
|
|
|
// all variants of a Date are internally stored as Date, so we can convert
|
|
// from everything to everything (also from ISODate to Number for example)
|
|
if (this._options.type) {
|
|
var fields = Object.keys(this._options.type);
|
|
for (var i = 0, len = fields.length; i < len; i++) {
|
|
var field = fields[i];
|
|
var value = this._options.type[field];
|
|
if (value == 'Date' || value == 'ISODate' || value == 'ASPDate') {
|
|
this._type[field] = 'Date';
|
|
}
|
|
else {
|
|
this._type[field] = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
this._subscribers = {}; // event subscribers
|
|
|
|
// add initial data when provided
|
|
if (data) {
|
|
this.add(data);
|
|
}
|
|
|
|
this.setOptions(options);
|
|
}
|
|
|
|
/**
|
|
* @param {Object} options Available options:
|
|
* {Object} queue Queue changes to the DataSet,
|
|
* flush them all at once.
|
|
* Queue options:
|
|
* - {number} delay Delay in ms, null by default
|
|
* - {number} max Maximum number of entries in the queue, Infinity by default
|
|
*/
|
|
DataSet.prototype.setOptions = function(options) {
|
|
if (options && options.queue !== undefined) {
|
|
if (options.queue === false) {
|
|
// delete queue if loaded
|
|
if (this._queue) {
|
|
this._queue.destroy();
|
|
delete this._queue;
|
|
}
|
|
}
|
|
else {
|
|
// create queue and update its options
|
|
if (!this._queue) {
|
|
this._queue = Queue.extend(this, {
|
|
replace: ['add', 'update', 'remove']
|
|
});
|
|
}
|
|
|
|
if (typeof options.queue === 'object') {
|
|
this._queue.setOptions(options.queue);
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Subscribe to an event, add an event listener
|
|
* @param {string} event Event name. Available events: 'add', 'update',
|
|
* 'remove'
|
|
* @param {function} callback Callback method. Called with three parameters:
|
|
* {string} event
|
|
* {Object | null} params
|
|
* {string | number} senderId
|
|
*/
|
|
DataSet.prototype.on = function(event, callback) {
|
|
var subscribers = this._subscribers[event];
|
|
if (!subscribers) {
|
|
subscribers = [];
|
|
this._subscribers[event] = subscribers;
|
|
}
|
|
|
|
subscribers.push({
|
|
callback: callback
|
|
});
|
|
};
|
|
|
|
/**
|
|
* Unsubscribe from an event, remove an event listener
|
|
* @param {string} event
|
|
* @param {function} callback
|
|
*/
|
|
DataSet.prototype.off = function(event, callback) {
|
|
var subscribers = this._subscribers[event];
|
|
if (subscribers) {
|
|
this._subscribers[event] = subscribers.filter(listener => listener.callback != callback);
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Trigger an event
|
|
* @param {string} event
|
|
* @param {Object | null} params
|
|
* @param {string} [senderId] Optional id of the sender.
|
|
* @private
|
|
*/
|
|
DataSet.prototype._trigger = function (event, params, senderId) {
|
|
if (event == '*') {
|
|
throw new Error('Cannot trigger event *');
|
|
}
|
|
|
|
var subscribers = [];
|
|
if (event in this._subscribers) {
|
|
subscribers = subscribers.concat(this._subscribers[event]);
|
|
}
|
|
if ('*' in this._subscribers) {
|
|
subscribers = subscribers.concat(this._subscribers['*']);
|
|
}
|
|
|
|
for (var i = 0, len = subscribers.length; i < len; i++) {
|
|
var subscriber = subscribers[i];
|
|
if (subscriber.callback) {
|
|
subscriber.callback(event, params, senderId || null);
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Add data.
|
|
* Adding an item will fail when there already is an item with the same id.
|
|
* @param {Object | Array} data
|
|
* @param {string} [senderId] Optional sender id
|
|
* @return {Array.<string|number>} addedIds Array with the ids of the added items
|
|
*/
|
|
DataSet.prototype.add = function (data, senderId) {
|
|
var addedIds = [],
|
|
id,
|
|
me = this;
|
|
|
|
if (Array.isArray(data)) {
|
|
// Array
|
|
for (var i = 0, len = data.length; i < len; i++) {
|
|
id = me._addItem(data[i]);
|
|
addedIds.push(id);
|
|
}
|
|
}
|
|
else if (data && typeof data === 'object') {
|
|
// Single item
|
|
id = me._addItem(data);
|
|
addedIds.push(id);
|
|
}
|
|
else {
|
|
throw new Error('Unknown dataType');
|
|
}
|
|
|
|
if (addedIds.length) {
|
|
this._trigger('add', {items: addedIds}, senderId);
|
|
}
|
|
|
|
return addedIds;
|
|
};
|
|
|
|
/**
|
|
* Update existing items. When an item does not exist, it will be created
|
|
* @param {Object | Array} data
|
|
* @param {string} [senderId] Optional sender id
|
|
* @return {Array.<string|number>} updatedIds The ids of the added or updated items
|
|
* @throws {Error} Unknown Datatype
|
|
*/
|
|
DataSet.prototype.update = function (data, senderId) {
|
|
var addedIds = [];
|
|
var updatedIds = [];
|
|
var oldData = [];
|
|
var updatedData = [];
|
|
var me = this;
|
|
var fieldId = me._fieldId;
|
|
|
|
var addOrUpdate = function (item) {
|
|
var id = item[fieldId];
|
|
if (me._data[id]) {
|
|
var oldItem = util.extend({}, me._data[id]);
|
|
// update item
|
|
id = me._updateItem(item);
|
|
updatedIds.push(id);
|
|
updatedData.push(item);
|
|
oldData.push(oldItem);
|
|
}
|
|
else {
|
|
// add new item
|
|
id = me._addItem(item);
|
|
addedIds.push(id);
|
|
}
|
|
};
|
|
|
|
if (Array.isArray(data)) {
|
|
// Array
|
|
for (var i = 0, len = data.length; i < len; i++) {
|
|
if (data[i] && typeof data[i] === 'object'){
|
|
addOrUpdate(data[i]);
|
|
} else {
|
|
console.warn('Ignoring input item, which is not an object at index ' + i);
|
|
}
|
|
}
|
|
}
|
|
else if (data && typeof data === 'object') {
|
|
// Single item
|
|
addOrUpdate(data);
|
|
}
|
|
else {
|
|
throw new Error('Unknown dataType');
|
|
}
|
|
|
|
if (addedIds.length) {
|
|
this._trigger('add', {items: addedIds}, senderId);
|
|
}
|
|
if (updatedIds.length) {
|
|
var props = { items: updatedIds, oldData: oldData, data: updatedData };
|
|
// TODO: remove deprecated property 'data' some day
|
|
//Object.defineProperty(props, 'data', {
|
|
// 'get': (function() {
|
|
// console.warn('Property data is deprecated. Use DataSet.get(ids) to retrieve the new data, use the oldData property on this object to get the old data');
|
|
// return updatedData;
|
|
// }).bind(this)
|
|
//});
|
|
this._trigger('update', props, senderId);
|
|
}
|
|
|
|
return addedIds.concat(updatedIds);
|
|
};
|
|
|
|
/**
|
|
* Get a data item or multiple items.
|
|
*
|
|
* Usage:
|
|
*
|
|
* get()
|
|
* get(options: Object)
|
|
*
|
|
* get(id: number | string)
|
|
* get(id: number | string, options: Object)
|
|
*
|
|
* get(ids: number[] | string[])
|
|
* get(ids: number[] | string[], options: Object)
|
|
*
|
|
* Where:
|
|
*
|
|
* {number | string} id The id of an item
|
|
* {number[] | string{}} ids An array with ids of items
|
|
* {Object} options An Object with options. Available options:
|
|
* {string} [returnType] Type of data to be returned.
|
|
* Can be 'Array' (default) or 'Object'.
|
|
* {Object.<string, string>} [type]
|
|
* {string[]} [fields] field names to be returned
|
|
* {function} [filter] filter items
|
|
* {string | function} [order] Order the items by a field name or custom sort function.
|
|
* @param {Array} args
|
|
* @returns {DataSet}
|
|
* @throws Error
|
|
*/
|
|
DataSet.prototype.get = function (args) { // eslint-disable-line no-unused-vars
|
|
var me = this;
|
|
|
|
// parse the arguments
|
|
var id, ids, options;
|
|
var firstType = util.getType(arguments[0]);
|
|
if (firstType == 'String' || firstType == 'Number') {
|
|
// get(id [, options])
|
|
id = arguments[0];
|
|
options = arguments[1];
|
|
}
|
|
else if (firstType == 'Array') {
|
|
// get(ids [, options])
|
|
ids = arguments[0];
|
|
options = arguments[1];
|
|
}
|
|
else {
|
|
// get([, options])
|
|
options = arguments[0];
|
|
}
|
|
|
|
// determine the return type
|
|
var returnType;
|
|
if (options && options.returnType) {
|
|
var allowedValues = ['Array', 'Object'];
|
|
returnType = allowedValues.indexOf(options.returnType) == -1 ? 'Array' : options.returnType;
|
|
}
|
|
else {
|
|
returnType = 'Array';
|
|
}
|
|
|
|
// build options
|
|
var type = options && options.type || this._options.type;
|
|
var filter = options && options.filter;
|
|
var items = [], item, itemIds, itemId, i, len;
|
|
|
|
// convert items
|
|
if (id != undefined) {
|
|
// return a single item
|
|
item = me._getItem(id, type);
|
|
if (item && filter && !filter(item)) {
|
|
item = null;
|
|
}
|
|
}
|
|
else if (ids != undefined) {
|
|
// return a subset of items
|
|
for (i = 0, len = ids.length; i < len; i++) {
|
|
item = me._getItem(ids[i], type);
|
|
if (!filter || filter(item)) {
|
|
items.push(item);
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
// return all items
|
|
itemIds = Object.keys(this._data);
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
itemId = itemIds[i];
|
|
item = me._getItem(itemId, type);
|
|
if (!filter || filter(item)) {
|
|
items.push(item);
|
|
}
|
|
}
|
|
}
|
|
|
|
// order the results
|
|
if (options && options.order && id == undefined) {
|
|
this._sort(items, options.order);
|
|
}
|
|
|
|
// filter fields of the items
|
|
if (options && options.fields) {
|
|
var fields = options.fields;
|
|
if (id != undefined) {
|
|
item = this._filterFields(item, fields);
|
|
}
|
|
else {
|
|
for (i = 0, len = items.length; i < len; i++) {
|
|
items[i] = this._filterFields(items[i], fields);
|
|
}
|
|
}
|
|
}
|
|
|
|
// return the results
|
|
if (returnType == 'Object') {
|
|
var result = {},
|
|
resultant;
|
|
for (i = 0, len = items.length; i < len; i++) {
|
|
resultant = items[i];
|
|
result[resultant.id] = resultant;
|
|
}
|
|
return result;
|
|
}
|
|
else {
|
|
if (id != undefined) {
|
|
// a single item
|
|
return item;
|
|
}
|
|
else {
|
|
// just return our array
|
|
return items;
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Get ids of all items or from a filtered set of items.
|
|
* @param {Object} [options] An Object with options. Available options:
|
|
* {function} [filter] filter items
|
|
* {string | function} [order] Order the items by
|
|
* a field name or custom sort function.
|
|
* @return {Array.<string|number>} ids
|
|
*/
|
|
DataSet.prototype.getIds = function (options) {
|
|
var data = this._data,
|
|
filter = options && options.filter,
|
|
order = options && options.order,
|
|
type = options && options.type || this._options.type,
|
|
itemIds = Object.keys(data),
|
|
i,
|
|
len,
|
|
id,
|
|
item,
|
|
items,
|
|
ids = [];
|
|
|
|
if (filter) {
|
|
// get filtered items
|
|
if (order) {
|
|
// create ordered list
|
|
items = [];
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
item = this._getItem(id, type);
|
|
if (filter(item)) {
|
|
items.push(item);
|
|
}
|
|
}
|
|
|
|
this._sort(items, order);
|
|
|
|
for (i = 0, len = items.length; i < len; i++) {
|
|
ids.push(items[i][this._fieldId]);
|
|
}
|
|
}
|
|
else {
|
|
// create unordered list
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
item = this._getItem(id, type);
|
|
if (filter(item)) {
|
|
ids.push(item[this._fieldId]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else {
|
|
// get all items
|
|
if (order) {
|
|
// create an ordered list
|
|
items = [];
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
items.push(data[id]);
|
|
}
|
|
|
|
this._sort(items, order);
|
|
|
|
for (i = 0, len = items.length; i < len; i++) {
|
|
ids.push(items[i][this._fieldId]);
|
|
}
|
|
}
|
|
else {
|
|
// create unordered list
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
item = data[id];
|
|
ids.push(item[this._fieldId]);
|
|
}
|
|
}
|
|
}
|
|
|
|
return ids;
|
|
};
|
|
|
|
/**
|
|
* Returns the DataSet itself. Is overwritten for example by the DataView,
|
|
* which returns the DataSet it is connected to instead.
|
|
* @returns {DataSet}
|
|
*/
|
|
DataSet.prototype.getDataSet = function () {
|
|
return this;
|
|
};
|
|
|
|
/**
|
|
* Execute a callback function for every item in the dataset.
|
|
* @param {function} callback
|
|
* @param {Object} [options] Available options:
|
|
* {Object.<string, string>} [type]
|
|
* {string[]} [fields] filter fields
|
|
* {function} [filter] filter items
|
|
* {string | function} [order] Order the items by
|
|
* a field name or custom sort function.
|
|
*/
|
|
DataSet.prototype.forEach = function (callback, options) {
|
|
var filter = options && options.filter,
|
|
type = options && options.type || this._options.type,
|
|
data = this._data,
|
|
itemIds = Object.keys(data),
|
|
i,
|
|
len,
|
|
item,
|
|
id;
|
|
|
|
if (options && options.order) {
|
|
// execute forEach on ordered list
|
|
var items = this.get(options);
|
|
|
|
for (i = 0, len = items.length; i < len; i++) {
|
|
item = items[i];
|
|
id = item[this._fieldId];
|
|
callback(item, id);
|
|
}
|
|
}
|
|
else {
|
|
// unordered
|
|
for (i = 0, len = itemIds.length; i < len; i++) {
|
|
id = itemIds[i];
|
|
item = this._getItem(id, type);
|
|
if (!filter || filter(item)) {
|
|
callback(item, id);
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
/**
|
|
* Map every item in the dataset.
|
|
* @param {function} callback
|
|
* @param {Object} [options] Available options:
|
|
* {Object.<string, string>} [type]
|
|
* {string[]} [fields] filter fields
|
|
* {function} [filter] filter items
|
|
* {string | function} [order] Order the items by
|
|
* a field name or custom sort function.
|
|
* @return {Object[]} mappedItems
|
|
*/
|
|
DataSet.prototype.map = function (callback, options) {
|
|
var filter = options && options.filter,
|
|
type = options && options.type || this._options.type,
|
|
mappedItems = [],
|
|
data = this._data,
|
|
itemIds = Object.keys(data),
|
|
i,
|
|
len,
|
|
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.<string|number>} id Object or id, or an array with
|
|
* objects or ids to be removed
|
|
* @param {string} [senderId] Optional sender id
|
|
* @return {Array.<string|number>} removedIds
|
|
*/
|
|
DataSet.prototype.remove = function (id, senderId) {
|
|
var removedIds = [],
|
|
removedItems = [],
|
|
ids = [],
|
|
i, len, itemId, item;
|
|
|
|
// force everything to be an array for simplicity
|
|
ids = Array.isArray(id) ? id : [id];
|
|
|
|
for (i = 0, len = ids.length; i < len; i++) {
|
|
item = this._remove(ids[i]);
|
|
if (item) {
|
|
itemId = item[this._fieldId];
|
|
if (itemId != undefined) {
|
|
removedIds.push(itemId);
|
|
removedItems.push(item);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (removedIds.length) {
|
|
this._trigger('remove', {items: removedIds, oldData: removedItems}, 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) {
|
|
var item,
|
|
ident;
|
|
|
|
// confirm the id to use based on the args type
|
|
if (util.isNumber(id) || util.isString(id)) {
|
|
ident = id;
|
|
}
|
|
else if (id && typeof id === 'object') {
|
|
ident = id[this._fieldId]; // look for the identifier field using _fieldId
|
|
}
|
|
|
|
// do the remove if the item is found
|
|
if (ident !== undefined && this._data[ident]) {
|
|
item = this._data[ident];
|
|
delete this._data[ident];
|
|
this.length--;
|
|
return item;
|
|
}
|
|
return null;
|
|
};
|
|
|
|
/**
|
|
* Clear the data
|
|
* @param {string} [senderId] Optional sender id
|
|
* @return {Array.<string|number>} removedIds The ids of all removed items
|
|
*/
|
|
DataSet.prototype.clear = function (senderId) {
|
|
var i, len;
|
|
var ids = Object.keys(this._data);
|
|
var items = [];
|
|
|
|
for (i = 0, len = ids.length; i < len; i++) {
|
|
items.push(this._data[ids[i]]);
|
|
}
|
|
|
|
this._data = {};
|
|
this.length = 0;
|
|
|
|
this._trigger('remove', {items: ids, oldData: items}, 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;
|
|
}
|
|
}
|
|
|
|
if (!converted[this._fieldId]) {
|
|
converted[this._fieldId] = raw.id;
|
|
}
|
|
|
|
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;
|