d3-annotate

Interactively add, edit, move and save SVG chart annotations.

Install

If you use NPM, npm install d3-annotate. Otherwise, download the latest release.

Interactions

Drag to move

Click an element from selection to add annotation

Command + Click to remove an annotation

Shift + Click to edit annotation copy then [Enter] or unfocus text input to save

API

####d3.annotate()

Initialize a new annotation behavior.

.container([d3 <g> or <svg> selection]) (required)

Sets container to render annotations to. _Note: should have translate to match data.

.key([fn]) (d) => d.id by default

Sets key to be used for serializing annotations and joining annotations with data

.text([fn]) indentity by default

Sets the default text for an annotation. eg: .text((d) => `${d.name}: ${d.score}`)

.attr([attrName(eg: x, y, text-anchor, fill)], [value or fn]) (similar to d3.select(...).attr)

.attr will get called on <text> elements created from annotation. However, instead of only having access to the bound data(d.data) - you have access to what is returned from .getBBox() of the target element (d.box), eg:

// Place labels to the left of target element (centered vertically and horizontally by default)
.attr('x', (d) => d.box.x)
.attr('text-anchor', 'end')
  
// Color labels based on data in target element
.attr('fill', (d) => palette(d.data.category))

.show([boolean or function])

Create annotations automatically(true will create an annotation for every datum)

.saved([annotation object])

Add object of annotations to be rendered on .call(annotation), created from calling annotation.serialize()

.serialize()

Returns an object of annotations based on current state of annotations.

Example Usage

// render some chart elements with data
var bubbles = chartArea.selectAll('.bubble').data(cars) ....

var annotation = d3.annotate()
      .continer(chartArea.append('g'))
      .key((d) => d.model + d.year)
      .text((d) => `${d.make} ${d.model}: ${d.mpg} miles per gallon`)
      .show((d) => d.year === 2016) // create annotations only for 2016 models, initially
      .saved({'prius2015':{text:'Most efficient',x:400,y:600}})
      .attr('fill', (d) => makeColors(d.data.make));

d3.selectAll('.bubble').call(annotation); // <text> elements get created
[User interaction to move, edit, rewrite annotations]
JSON.stringify(annotation.serialize()) // can be saved for creating inital annotation state

CSS

To style annotations, use a selector a la:

#myChart .d3-an-container .annotation 

For a better experience, add the following CSS to your page or CSS build system:

.d3-an-container .annotation { cursor: move; }
.d3-an-container .annotation.dragging {
  cursor: grabbing;
  cursor: -moz-grabbing;
  cursor: -webkit-grabbing;
  text-decoration: underline; }
.d3-an-text-edit {
  position: fixed;
  top: 40px;
  left: 40px; }

Author

By @ChrisPolis

License

This project is licensed under the terms of the MIT license.