Timeline documentation

Overview

The Timeline is an interactive visualization chart to visualize data in time. The data items can take place on a single date, or have a start and end date (a range). You can freely move and zoom in the timeline by dragging and scrolling in the Timeline. Items can be created, edited, and deleted in the timeline. The time scale on the axis is adjusted automatically, and supports scales ranging from milliseconds to years.

Timeline uses regular HTML DOM to render the timeline and items put on the timeline. This allows for flexible customization using css styling.

Contents

Example

The following code shows how to create a Timeline and provide it with data. More examples can be found in the examples directory. 

<!DOCTYPE HTML>
<html>
<head>
  <title>Timeline | Basic demo</title>

  <style type="text/css">
    body, html {
      font-family: sans-serif;
    }
  </style>

  <script src="../../dist/vis.js"></script>
  <link href="../../dist/vis.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="visualization"></div>

<script type="text/javascript">
  // DOM element where the Timeline will be attached
  var container = document.getElementById('visualization');

  // Create a DataSet (allows two way data-binding)
  var items = new vis.DataSet([
    {id: 1, content: 'item 1', start: '2013-04-20'},
    {id: 2, content: 'item 2', start: '2013-04-14'},
    {id: 3, content: 'item 3', start: '2013-04-18'},
    {id: 4, content: 'item 4', start: '2013-04-16', end: '2013-04-19'},
    {id: 5, content: 'item 5', start: '2013-04-25'},
    {id: 6, content: 'item 6', start: '2013-04-27'}
  ]);

  // Configuration for the Timeline
  var options = {};

  // Create a Timeline
  var timeline = new vis.Timeline(container, items, options);
</script>
</body>
</html>

Loading

Install or download the vis.js library. in a subfolder of your project. Include the libraries script and css files in the head of your html code: 

<script src="vis/dist/vis.js"></script>
<link href="vis/dist/vis.css" rel="stylesheet" type="text/css" />
The constructor of the Timeline is vis.Timeline 
var timeline = new vis.Timeline(container, items, options);
The constructor accepts three parameters:

Data Format

The timeline can be provided with two types of data:

Items

The Timeline uses regular Arrays and Objects as data format. Data items can contain the properties start, end (optional), content, group (optional), and className (optional).

A table is constructed as: 

var items = [
  {
    start: new Date(2010, 7, 15),
    end: new Date(2010, 8, 2),  // end is optional
    content: 'Trajectory A'
    // Optional: fields 'id', 'type', 'group', 'className'
  }
  // more items...
]);

The item properties are defined as:

Name Type Required Description
className String no This field is optional. A className can be used to give items an individual css style. For example, when an item has className 'red', one can define a css style like: 
.vis.timeline .red {
  color: white;
  background-color: red;
  border-color: darkred;
}
More details on how to style items can be found in the section Styles.
content String yes The contents of the item. This can be plain text or html code.
end Date no The end date of the item. The end date is optional, and can be left null. If end date is provided, the item is displayed as a range. If not, the item is displayed as a box.
group any type no This field is optional. When the group column is provided, all items with the same group are placed on one line. A vertical axis is displayed showing the groups. Grouping items can be useful for example when showing availability of multiple people, rooms, or other resources next to each other.
id String | Number no An id for the item. Using an id is not required but highly recommended. An id is needed when dynamically adding, updating, and removing items in a DataSet.
start Date yes The start date of the item, for example new Date(2010,9,23).
title String none Add a title for the item, displayed when holding the mouse on the item. The title can only contain plain text.
type String 'box' The type of the item. Can be 'box' (default), 'point', or 'range'. Types 'box' and 'point' need a start date, and type 'range' needs both a start and end date.

Groups

Like the items, groups are regular JavaScript Arrays and Objects. Using groups, items can be grouped together. Items are filtered per group, and displayed as Group items can contain the properties id, content, and className (optional).

Groups can be applied to a timeline using the method setGroups. A table with groups can be created like: 

var groups = [
  {
    id: 1,
    content: 'Group 1'
    // Optional: a field 'className'
  }
  // more groups...
]);

Groups can have the following properties:

Name Type Required Description
className String no This field is optional. A className can be used to give groups an individual css style. For example, when a group has className 'red', one can define a css style .red { color: red; } . More details on how to style groups can be found in the section Styles.
content String yes The contents of the group. This can be plain text or html code.
id String | Number yes An id for the group. The group will display all items having a property group which matches the id of the group.
title String none A title for the group, displayed when holding the mouse the groups label. The title can only contain plain text.

Configuration Options

Options can be used to customize the timeline. Options are defined as a JSON object. All options are optional. 

var options = {
  width: '100%',
  height: '30px',
  margin: {
    item: 20
  }
};

The following options are available.

Name Type Default Description
align String "center" Alignment of items with type 'box'. Available values are 'center' (default), 'left', or 'right').
autoResize boolean true If true, the Timeline will automatically detect when its container is resized, and redraw itself accordingly. If false, the Timeline can be forced to repaint after its container has been resized using the function redraw().
editable Boolean | Object false If true, the items in the timeline can be manipulated. Only applicable when option selectable is true. See also the callbacks onAdd, onUpdate, onMove, and onRemove. When editable is an object, one can enable or disable individual manipulation actions. See section Editing Items for a detailed explanation.
editable.add Boolean false If true, new items can be created by double tapping an empty space in the Timeline. See section Editing Items for a detailed explanation.
editable.remove Boolean false If true, items can be deleted by first selecting them, and then clicking the delete button on the top right of the item. See section Editing Items for a detailed explanation.
editable.updateGroup Boolean false If true, items can be dragged from one group to another. Only applicable when the Timeline has groups. See section Editing Items for a detailed explanation.
editable.updateTime Boolean false If true, items can be dragged to another moment in time. See section Editing Items for a detailed explanation.
end Date | Number | String none The initial end date for the axis of the timeline. If not provided, the latest date present in the items set is taken as end date.
groupOrder String | Function none Order the groups by a field name or custom sort function. By default, groups are not ordered.
height Number | String none The height of the timeline in pixels or as a percentage. When height is undefined or null, the height of the timeline is automatically adjusted to fit the contents. It is possible to set a maximum height using option maxHeight to prevent the timeline from getting too high in case of automatically calculated height.
margin.axis Number 20 The minimal margin in pixels between items and the time axis.
margin.item Number 10 The minimal margin in pixels between items.
max Date | Number | String none Set a maximum Date for the visible range. It will not be possible to move beyond this maximum.
maxHeight Number | String none Specifies the maximum height for the Timeline. Can be a number in pixels or a string like "300px".
min Date | Number | String none Set a minimum Date for the visible range. It will not be possible to move beyond this minimum.
minHeight Number | String none Specifies the minimum height for the Timeline. Can be a number in pixels or a string like "300px".
moveable Boolean true Specifies whether the Timeline can be moved and zoomed by dragging the window. See also option zoomable.
onAdd Function none Callback function triggered when an item is about to be added: when the user double taps an empty space in the Timeline. See section Editing Items for more information. Only applicable when both options selectable and editable.add are set true.
onUpdate Function none Callback function triggered when an item is about to be updated, when the user double taps an item in the Timeline. See section Editing Items for more information. Only applicable when both options selectable and editable.updateTime or editable.updateGroup are set true.
onMove Function none Callback function triggered when an item has been moved: after the user has dragged the item to an other position. See section Editing Items for more information. Only applicable when both options selectable and editable.updateTime or editable.updateGroup are set true.
onRemove Function none Callback function triggered when an item is about to be removed: when the user tapped the delete button on the top right of a selected item. See section Editing Items for more information. Only applicable when both options selectable and editable.remove are set true.
orientation String 'bottom' Orientation of the timeline: 'top' or 'bottom' (default). If orientation is 'bottom', the time axis is drawn at the bottom, and if 'top', the axis is drawn on top.
padding Number 5 The padding of items, needed to correctly calculate the size of item ranges. Must correspond with the css of items, for example when setting options.padding=10, corresponding css is: 
.vis.timeline .item {
  padding: 10px;
}
selectable Boolean true If true, the items on the timeline can be selected. Multiple items can be selected by long pressing them, or by using ctrl+click or shift+click. The event select is fired each time the selection has changed (see section Events).
showCurrentTime boolean true Show a vertical bar at the current time.
showCustomTime boolean false Show a vertical bar displaying a custom time. This line can be dragged by the user. The custom time can be utilized to show a state in the past or in the future. When the custom time bar is dragged by the user, the event timechange is fired repeatedly. After the bar is dragged, the event timechanged is fired once.
showMajorLabels boolean true By default, the timeline shows both minor and major date labels on the time axis. For example the minor labels show minutes and the major labels show hours. When showMajorLabels is false, no major labels are shown.
showMinorLabels boolean true By default, the timeline shows both minor and major date labels on the time axis. For example the minor labels show minutes and the major labels show hours. When showMinorLabels is false, no minor labels are shown. When both showMajorLabels and showMinorLabels are false, no horizontal axis will be visible.
stack Boolean true If true (default), items will be stacked on top of each other such that they do not overlap.
start Date | Number | String none The initial start date for the axis of the timeline. If not provided, the earliest date present in the events is taken as start date.
type String none Specifies the default type for the timeline items. Choose from 'box', 'point', and 'range'. Note that individual items can override this default type. If undefined, the Timeline will auto detect the type from the items data: if a start and end date is available, a 'range' will be created, and else, a 'box' is created.
width String '100%' The width of the timeline in pixels or as a percentage.
zoomable Boolean true Specifies whether the Timeline can be zoomed by pinching or scrolling in the window. Only applicable when option moveable is set true.
zoomMax Number 315360000000000 Set a maximum zoom interval for the visible range in milliseconds. It will not be possible to zoom out further than this maximum. Default value equals about 10000 years.
zoomMin Number 10 Set a minimum zoom interval for the visible range in milliseconds. It will not be possible to zoom in further than this minimum.

Methods

The Timeline supports the following methods.

Method Return Type Description
clear([what]) none Clear the Timeline. An object can be passed specifying which sections to clear: items, groups, and/or options. By Default, items, groups and options are cleared, i.e. what = {items: true, groups: true, options: true}. Example usage: 
timeline.clear();                // clear items, groups, and options
timeline.clear({options: true}); // clear options only
destroy() none Destroy the Timeline. The timeline is removed from memory. all DOM elements and event listeners are cleaned up.
fit() none Adjust the visible window such that it fits all items.
getCustomTime() Date Retrieve the custom time. Only applicable when the option showCustomTime is true.
setCustomTime(time) none Adjust the custom time bar. Only applicable when the option showCustomTime is true. time is a Date object.
getSelection() Number[] Get an array with the ids of the currently selected items.
getWindow() Object Get the current visible window. Returns an object with properties start: Date and end: Date.
on(event, callback) none Create an event listener. The callback function is invoked every time the event is triggered. Avialable events: rangechange, rangechanged, select. The callback function is invoked as callback(properties), where properties is an object containing event specific properties. See section Events for more information.
off(event, callback) none Remove an event listener created before via function on(event, callback). See section Events for more information.
redraw() none Force a redraw of the Timeline. Can be useful to manually redraw when option autoResize=false.
setGroups(groups) none Set a data set with groups for the Timeline. groups can be an Array with Objects, a DataSet, or a DataView. For each of the groups, the items of the timeline are filtered on the property group, which must correspond with the id of the group.
setItems(items) none Set a data set with items for the Timeline. items can be an Array with Objects, a DataSet, or a DataView.
setOptions(options) none Set or update options. It is possible to change any option of the timeline at any time. You can for example switch orientation on the fly.
setSelection([ids]) none Select or deselect items. Currently selected items will be unselected.
setWindow(start, end) none Set the current visible window. The parameters start and end can be a Date, Number, or String. If the parameter value of start or end is null, the parameter will be left unchanged.

Events

Timeline fires events when changing the visible window by dragging, when selecting items, and when dragging the custom time bar.

Here an example on how to listen for a select event. 

timeline.on('select', function (properties) {
  alert('selected items: ' + properties.nodes);
});

A listener can be removed via the function off: 

function onSelect (properties) {
  alert('selected items: ' + properties.nodes);
}

// add event listener
timeline.on('select', onSelect);

// do stuff...

// remove event listener
timeline.off('select', onSelect);

The following events are available.

name Description Properties
rangechange Fired repeatedly when the user is dragging the timeline window.
  • start (Number): timestamp of the current start of the window.
  • end (Number): timestamp of the current end of the window.
rangechanged Fired once after the user has dragged the timeline window.
  • start (Number): timestamp of the current start of the window.
  • end (Number): timestamp of the current end of the window.
select Fired after the user selects or deselects items by tapping or holding them. When a use taps an already selected item, the select event is fired again. Not fired when the method setSelectionis executed.
  • items: an array with the ids of the selected items
timechange Fired repeatedly when the user is dragging the custom time bar. Only available when the custom time bar is enabled.
  • time (Date): the current time.
timechanged Fired once after the user has dragged the custom time bar. Only available when the custom time bar is enabled.
  • time (Date): the current time.

Editing Items

When the Timeline is configured to be editable (both options selectable and editable are true), the user can move items by dragging them, can create a new item by double tapping on an empty space, can update an item by double tapping it, and can delete a selected item by clicking the delete button on the top right.

Option editable accepts a boolean or an object. When editable is a boolean, all manipulation actions will be either enabled or disabled. When editable is an object, one can enable individual manipulation actions:

// enable or disable all manipulation actions
var options = {
  editable: true       // true or false
};

// enable or disable individual manipulation actions
var options = {
  editable: {
    add: true,         // add new items by double tapping
    updateTime: true,  // drag items horizontally
    updateGroup: true, // drag items from one group to another
    remove: true       // delete an item by tapping the delete button top right
  }
};

One can specify callback functions to validate changes made by the user. There are a number of callback functions for this purpose:

Each of the callbacks is invoked with two arguments:

Example code: 

var options = {
  onUpdate: function (item, callback) {
    item.content = prompt('Edit items text:', item.content);
    if (item.content != null) {
      callback(item); // send back adjusted item
    }
    else {
      callback(null); // cancel updating the item
    }
  }
}
A full example is available here: 08_edit_items.html.

Styles

All parts of the Timeline have a class name and a default css style. The styles can be overwritten, which enables full customization of the layout of the Timeline.

For example, to change the border and background color of all items, include the following code inside the head of your html code or in a separate stylesheet.

<style>
  .vis.timeline .item {
    border-color: orange;
    background-color: yellow;
  }
</style>

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