<!doctype html> <html> <head> <title>vis.js | DataSet documentation</title> <link href="css/prettify.css" type="text/css" rel="stylesheet" /> <link href='css/style.css' type='text/css' rel='stylesheet'> <script type="text/javascript" src="lib/prettify/prettify.js"></script> </head> <body onload="prettyPrint();"> <div id="container"> <h1>DataSet documentation</h1> <h2 id="Contents">Contents</h2> <ul> <li><a href="#Overview">Overview</a></li> <li><a href="#Example">Example</a></li> <li><a href="#Construction">Construction</a></li> <li><a href="#Data_Manipulation">Data Manipulation</a></li> <li><a href="#Data_Filtering">Data Filtering</a></li> <li><a href="#Data_Formatting">Data Formatting</a></li> <li><a href="#Subscriptions">Subscriptions</a></li> <li><a href="#Data_Policy">Data Policy</a></li> </ul> <h2 id="Overview">Overview</h2> <p> Vis.js comes with a flexible DataSet, which can be used to hold and manipulate unstructured data and listen for changes in the data. The DataSet is key/value based. Data items can be added, updated and removed from the DatSet, and one can subscribe to changes in the DataSet. The data in the DataSet can be filtered and ordered, and fields (like dates) can be converted to a specific type. Data can be normalized when appending it to the DataSet as well. </p> <h2 id="Example">Example</h2> <p> The following example shows how to use a DataSet. </p> <pre class="prettyprint lang-js"> // create a DataSet var options = {}; var data = new vis.DataSet(options); // add items // note that the data items can contain different properties and data formats data.add([ {id: 1, text: 'item 1', date: new Date(2013, 6, 20), group: 1, first: true}, {id: 2, text: 'item 2', date: '2013-06-23', group: 2}, {id: 3, text: 'item 3', date: '2013-06-25', group: 2}, {id: 4, text: 'item 4'} ]); // subscribe to any change in the DataSet data.subscribe('*', function (event, params, senderId) { console.log('event', event, params); }); // update an existing item data.update({id: 2, group: 1}); // remove an item data.remove(4); // get all ids var ids = data.getIds(); console.log('ids', ids); // get a specific item var item1 = data.get(1); console.log('item1', item1); // retrieve a filtered subset of the data var items = data.get({ filter: function (item) { return item.group == 1; } }); console.log('filtered items', items); // retrieve formatted items var items = data.get({ fields: ['id', 'date'], convert: { date: 'ISODate' } }); console.log('formatted items', items); </pre> <h2 id="Construction">Construction</h2> <p> A DataSet can be constructed as: </p> <pre class="prettyprint lang-js"> var data = new vis.DataSet(options) </pre> <p> After construction, data can be added to the DataSet using the methods <code>add</code> and <code>update</code>, as described in section <a href="#Data_Manipulation">Data Manipulation</a>. </p> <p> The parameter <code>options</code> is optional and is an object which can contain the following properties: </p> <table> <tr> <th>Name</th> <th>Type</th> <th>Default value</th> <th>Description</th> </tr> <tr> <td>fieldId</td> <td>String</td> <td>"id"</td> <td> The name of the field containing the id of the items. When data is fetched from a server which uses some specific field to identify items, this field name can be specified in the DataSet using the option <code>fieldId</code>. For example <a href="http://couchdb.apache.org/" target="_blank">CouchDB</a> uses the field <code>"_id"</code> to identify documents. </td> </tr> <tr> <td>convert</td> <td>Object.<String, String></td> <td>none</td> <td> An object containing field names as key, and data types as value. By default, the type of the properties of items are left unchanged. Item properties can be normalized by specifying a field type. This is useful for example to automatically convert stringified dates coming from a server into JavaScript Date objects. The available data types are listed in section <a href="#Data_Types">Data Types</a>. </td> </tr> </table> <h2 id="Data_Manipulation">Data Manipulation</h2> <p> The data in a DataSet can be manipulated using the methods <a href="#Add"><code>add</code></a>, <a href="#Update"><code>update</code></a>, and <a href="#Remove"><code>remove</code></a>. The DataSet can be emptied using the method <a href="#Clear"><code>clear</code></a>. </p> <pre class="prettyprint lang-js"> // create a DataSet var data = new vis.DataSet(); // add items data.add([ {id: 1, text: 'item 1'}, {id: 2, text: 'item 2'}, {id: 3, text: 'item 3'} ]); // update an item data.update({id: 2, text: 'item 2 (updated)'}); // remove an item data.remove(3); </pre> <h3 id="Add">Add</h3> <p> Add a data item or an array with items. </p> Syntax: <pre class="prettyprint lang-js">var addedIds = DataSet.add(data [, senderId])</pre> The argument <code>data</code> can contain: <ul> <li> An <code>Object</code> containing a single item to be added. The item must contain an id. </li> <li> An <code>Array</code> or <code>google.visualization.DataTable</code> containing a list with items to be added. Each item must contain an id. </li> </ul> <p> After the items are added to the DataSet, the DataSet will trigger an event <code>add</code>. When a <code>senderId</code> is provided, this id will be passed with the triggered event to all subscribers. </p> <p> The method will throw an Error when an item with the same id as any of the added items already exists. </p> <h3 id="Update">Update</h3> <p> Update a data item or an array with items. </p> Syntax: <pre class="prettyprint lang-js">var updatedIds = DataSet.update(data [, senderId])</pre> The argument <code>data</code> can contain: <ul> <li> An <code>Object</code> containing a single item to be updated. The item must contain an id. </li> <li> An <code>Array</code> or <code>google.visualization.DataTable</code> containing a list with items to be updated. Each item must contain an id. </li> </ul> <p> The provided properties will be merged in the existing item. When an item does not exist, it will be created. </p> <p> After the items are updated, the DataSet will trigger an event <code>add</code> for the added items, and an event <code>update</code>. When a <code>senderId</code> is provided, this id will be passed with the triggered event to all subscribers. </p> <h3 id="Remove">Remove</h3> <p> Remove a data item or an array with items. </p> Syntax: <pre class="prettyprint lang-js">var removedIds = DataSet.remove(id [, senderId])</pre> <p> The argument <code>id</code> can be: </p> <ul> <li> A <code>Number</code> or <code>String</code> containing the id of a single item to be removed. </li> <li> An <code>Object</code> containing the item to be deleted. The item will be deleted by its id. </li> <li> An Array containing ids or items to be removed. </li> </ul> <p> The method ignores removal of non-existing items, and returns an array containing the ids of the items which are actually removed from the DataSet. </p> <p> After the items are removed, the DataSet will trigger an event <code>remove</code> for the removed items. When a <code>senderId</code> is provided, this id will be passed with the triggered event to all subscribers. </p> <h3 id="Clear">Clear</h3> <p> Clear the complete DataSet. </p> Syntax: <pre class="prettyprint lang-js">var removedIds = DataSet.clear([senderId])</pre> <p> After the items are removed, the DataSet will trigger an event <code>remove</code> for all removed items. When a <code>senderId</code> is provided, this id will be passed with the triggered event to all subscribers. </p> <h2 id="Data_Filtering">Data Filtering</h2> <p> Data can be retrieved from the DataSet using the method <code>get</code>. This method can return a single item or a list with items. </p> <p>A single item can be retrieved by its id:</p> <pre class="prettyprint lang-js"> var item1 = dataset.get(1); </pre> <p>A selection of items can be retrieved by providing an array with ids:</p> <pre class="prettyprint lang-js"> var items = dataset.get([1, 3, 4]); // retrieve items 1, 3, and 4 </pre> <p>All items can be retrieved by simply calling <code>get</code> without specifying an id:</p> <pre class="prettyprint lang-js"> var items = dataset.get(); // retrieve all items </pre> <p> Items can be filtered on specific properties by providing a filter function. A filter function is executed for each of the items in the DataSet, and is called with the item as parameter. The function must return a boolean. All items for which the filter function returns true will be emitted. </p> <pre class="prettyprint lang-js"> // retrieve all items having a property group with value 2 var group2 = dataset.get({ filter: function (item) { return (item.group == 2); } }); // retrieve all items having a property balance with a value above zero var positiveBalance = dataset.get({ filter: function (item) { return (item.balance > 0); } }); </pre> <h2 id="Data_Formatting">Data Formatting</h2> <p> The DataSet contains functionality to format data retrieved via the method <code>get</code>. The method <code>get</code> has the following syntax: </p> <pre class="prettyprint lang-js"> var item = DataSet.get(id, options); // retrieve a single item var items = DataSet.get(ids, options); // retrieve a selection of items var items = DataSet.get(options); // retrieve all items or a filtered set </pre> <p> Where <code>options</code> is an Object which can have the following properties: </p> <table> <tr> <th>Name</th> <th>Type</th> <th>Description</th> </tr> <tr> <td>fields</td> <td>String[ ]</td> <td> An array with field names. By default, all properties of the items are emitted. When <code>fields</code> is defined, only the properties whose name is specified in <code>fields</code> will be included in the returned items. </td> </tr> <tr> <td>convert</td> <td>Object.<String, String></td> <td> An object containing field names as key, and data types as value. By default, the type of the properties of an item are left unchanged. When a field type is specified, this field in the items will be converted to the specified type. This can be used for example to convert ISO strings containing a date to a JavaScript Date object, or convert strings to numbers or vice versa. The available data types are listed in section <a href="#Data_Types">Data Types</a>. </td> </tr> <tr> <td>filter</td> <td>function</td> <td>Items can be filtered on specific properties by providing a filter function. A filter function is executed for each of the items in the DataSet, and is called with the item as parameter. The function must return a boolean. All items for which the filter function returns true will be emitted. See section <a href="#Data_Filtering">Data Filtering</a>.</td> </tr> </table> <p> The following example demonstrates formatting properties and filtering properties from items. </p> <pre class="prettyprint lang-js"> // create a DataSet var data = new vis.DataSet(); data.add([ {id: 1, text: 'item 1', date: '2013-06-20', group: 1, first: true}, {id: 2, text: 'item 2', date: '2013-06-23', group: 2}, {id: 3, text: 'item 3', date: '2013-06-25', group: 2}, {id: 4, text: 'item 4'} ]); // retrieve formatted items var items = data.get({ fields: ['id', 'date', 'group'], // output the specified fields only convert: { date: 'Date', // convert the date fields to Date objects group: 'String' // convert the group fields to Strings } }); </pre> <h3 id="Data_Types">Data Types</h3> <p> DataSet supports the following data types: </p> <table style="width: 100%"> <tr> <th>Name</th> <th>Description</th> <th>Examples</th> </tr> <tr> <td>Boolean</td> <td>A JavaScript Boolean</td> <td> <code>true</code><br> <code>false</code> </td> </tr> <tr> <td>Number</td> <td>A JavaScript Number</td> <td> <code>32</code><br> <code>2.4</code> </td> </tr> <tr> <td>String</td> <td>A JavaScript String</td> <td> <code>"hello world"</code><br> <code>"2013-06-28"</code> </td> </tr> <tr> <td>Date</td> <td>A JavaScript Date object</td> <td> <code>new Date()</code><br> <code>new Date(2013, 5, 28)</code><br> <code>new Date(1372370400000)</code> </td> </tr> <tr> <td>Moment</td> <td>A Moment object, created with <a href="http://momentjs.com/" target="_blank">moment.js</a></td> <td> <code>moment()</code><br> <code>moment('2013-06-28')</code> </td> </tr> <tr> <td>ISODate</td> <td>A string containing an ISO Date</td> <td> <code>new Date().toISOString()</code><br> <code>"2013-06-27T22:00:00.000Z"</code> </td> </tr> <tr> <td>ASPDate</td> <td>A string containing an ASP Date</td> <td> <code>"/Date(1372370400000)/"</code><br> <code>"/Date(1198908717056-0700)/"</code> </td> </tr> </table> <h2 id="Subscriptions">Subscriptions</h2> <p> One can subscribe on changes in a DataSet. A subscription can be created using the method <code>subscribe</code>, and removed with <code>unsubscribe</code>. </p> <pre class="prettyprint lang-js"> // create a DataSet var data = new vis.DataSet(); // subscribe to any change in the DataSet data.subscribe('*', function (event, params, senderId) { console.log('event:', event, 'params:', params, 'senderId:', senderId); }); // add an item data.add({id: 1, text: 'item 1'}); // triggers an 'add' event data.update({id: 1, text: 'item 1 (updated)'}); // triggers an 'update' event data.remove(1); // triggers an 'remove' event </pre> <h3 id="Subscribe">Subscribe</h3> <p> Subscribe to an event. </p> Syntax: <pre class="prettyprint lang-js">DataSet.subscribe(event, callback)</pre> Where: <ul> <li> <code>event</code> is a String containing any of the events listed in section <a href="#Events">Events</a>. </li> <li> <code>callback</code> is a callback function which will be called each time the event occurs. The callback function is described in section <a href="#Callback">Callback</a>. </li> </ul> <h3 id="Unsubscribe">Unsubscribe</h3> <p> Unsubscribe from an event. </p> Syntax: <pre class="prettyprint lang-js">DataSet.unsubscribe(event, callback)</pre> Where <code>event</code> and <code>callback</code> correspond with the parameters used to <a href="#Subscribe">subscribe</a> to the event. <h3 id="Events">Events</h3> <p> The following events are available for subscription: </p> <table> <tr> <th>Event</th> <th>Description</th> </tr> <tr> <td>add</td> <td> The <code>add</code> event is triggered when an item or a set of items is added, or when an item is updated while not yet existing. </td> </tr> <tr> <td>update</td> <td> The <code>update</code> event is triggered when an existing item or a set of existing items is updated. </td> </tr> <tr> <td>remove</td> <td> The <code>remove</code> event is triggered when an item or a set of items is removed. </td> </tr> <tr> <td>*</td> <td> The <code>*</code> event is triggered when any of the events <code>add</code>, <code>update</code>, and <code>remove</code> occurs. </td> </tr> </table> <h3 id="Callback">Callback</h3> <p> The callback functions of subscribers are called with the following parameters: </p> <pre class="prettyprint lang-js"> function (event, params, senderId) { // handle the event }); </pre> <p> where the parameters are defined as </p> <table> <tr> <th>Parameter</th> <th>Type</th> <th>Description</th> </tr> <tr> <td>event</td> <td>String</td> <td> Any of the available events: <code>add</code>, <code>update</code>, or <code>remove</code>. </td> </tr> <tr> <td>params</td> <td>Object | null</td> <td> Optional parameters providing more information on the event. In case of the events <code>add</code>, <code>update</code>, and <code>remove</code>, <code>params</code> is always an object containing a property items, which contains an array with the ids of the affected items. </td> </tr> <tr> <td>senderId</td> <td>String | Number</td> <td> An senderId, optionally provided by the application code which triggered the event. If senderId is not provided, the argument will be <code>null</code>. </td> </tr> </table> <h2 id="Data_Policy">Data Policy</h2> <p> All code and data is processed and rendered in the browser. No data is sent to any server. </p> </div> </body> </html>