D3 Animations Bringing your Data to Life Extending transitions D3 is able to create animation effects In D3 animations are limited to a form of Key Frame Animation sequence i e two keys a start key and an end key The starting point of the animation is usually taken to be the current state of the DOM elements attributes styles Animation transitions in D3 are elegant and easy to setup and control In the example below the background color changes from the initial blue to the final yellow color DOCTYPE html html head script type text javascript src https d3js org d3 v7 min js script head body style height 50pt h1 Transitions to Animations h1 script d3 select body style background color blue tranasition style background color yellow script body html duration method The duration method transitions to change smoothly over a specified duration of time rather than instantaneously If you want the transition to take 4 seconds then you d set the transition duration as follow DOCTYPE html html head script type text javascript src https d3js org d3 v7 min js script head body style height 50pt h1 Transitions to Animations h1 script d3 selectAll h1 transition style color green duration 4000 script body html In the above example the h1 heading text changes color gradually over 4 seconds default black to green Also in addition to defining the color using the word you can also use the rgb define d3 selectAll h1 transition style color rgb 0 255 0 use rgb for exact color instead of names like green duration 4000 In the following example you ll transition the font size the color and the position of the h1 text DOCTYPE html html head script type text javascript src https d3js org d3 v7 min js script head body style height 50pt h1 Transitions to Animations h1 script d3 selectAll h1 transition style font size 28pt style color pink style transform translate 100pt 0 duration 4000 script body html D3 takes care of all the interpolation details for you in advance You just need to specify the desired transition duration and which parameters to change and everything else is handled for you delay method As you may have guessed from the name the delay method allows you to add a pause before your transition starts The delay parameter is the number of milliseconds 1000ms 1s Transition Lifecycle The D3 transition has a four phase lifecycle 1 The transition is schedules 2 The transition starts 3 The transition runs 4 The transition ends Let s review each of these in detail The Transition is Scheduled A transition is scheduled when it s created When we call selection and transition you re scheduling a transition This is also when you call attr and style transition methods to define the end key frame values The Transition Start The transition starts based on the delay which is specified when the transition is scheduled If you don t specify a delay the transition starts as soon as possible typically after a few milliseconds If you specify a delay the starting value should be set to when you want the transition to start d3 select body transition delay 200 wait 0 2 seconds before starting transition on start function callback when transition starts d3 select this style color blue style color red The Transitions Runs When the transition runs it s repeatedly invoked with values of the transition ranging from 0 to 1 Also the delay and duration have easing control timing details Easing distorts time to create a more asthetically desired result such as slow in and slow out Some easing functions may temporarily give values of t greater than 1 or less than 0 The Transition Ends The transition end time value is always exactly 1 The transition ends based on the sum of its delay and duration When a transition ends the end event is dispatched DOCTYPE html html head script type text javascript src https d3js org d3 v7 min js script head body style height 50pt h1 Transitions to Animations h1 script d3 selectAll h1 transition duration 4000 delay 100 on start function console log transition started style color pink style font size 28pt on end function console log transition ended script body html Using the on method you can connect event callbacks to let you know when transitions have started or ended you can also add in extra selects transitions inside these callbacks to build up a complex set of animations Note take care with D3 version numbers transition event callbacks was added in D3 version 3 0 older versions of D3 dispatched the start event after constructing tweens d3 v5 d3 select myid transition style opacity 0 on end myCallback old way d3 select myid transition style opacity 0 each end myCallback
Transition Lifecycle The D3 transition has a four phase lifecycle 1 The transition is schedules 2 The transition starts 3 The transition runs 4 The transition ends Let s review each of these in detail The Transition is Scheduled A transition is scheduled when it s created When we call selection and transition you re scheduling a transition This is also when you call attr and style transition methods to define the end key frame values The Transition Start The transition starts based on the delay which is specified when the transition is scheduled If you don t specify a delay the transition starts as soon as possible typically after a few milliseconds If you specify a delay the starting value should be set to when you want the transition to start d3 select body transition delay 200 wait 0 2 seconds before starting transition on start function callback when transition starts d3 select this style color blue style color red The Transitions Runs When the transition runs it s repeatedly invoked with values of the transition ranging from 0 to 1 Also the delay and duration have easing control timing details Easing distorts time to create a more asthetically desired result such as slow in and slow out Some easing functions may temporarily give values of t greater than 1 or less than 0 The Transition Ends The transition end time value is always exactly 1 The transition ends based on the sum of its delay and duration When a transition ends the end event is dispatched DOCTYPE html html head script type text javascript src https d3js org d3 v7 min js script head body style height 50pt h1 Transitions to Animations h1 script d3 selectAll h1 transition duration 4000 delay 100 on start function console log transition started style color pink style font size 28pt on end function console log transition ended script body html Using the on method you can connect event callbacks to let you know when transitions have started or ended you can also add in extra selects transitions inside these callbacks to build up a complex set of animations Note take care with D3 version numbers transition event callbacks was added in D3 version 3 0 older versions of D3 dispatched the start event after constructing tweens d3 v5 d3 select myid transition style opacity 0 on end myCallback old way d3 select myid transition style opacity 0 each end myCallback