arrows-svg

Library for creating SVG arrow between two HTML elements. Positions of elements are observed, so when they change arrow will rerender. There's also react implementation --> react-arrows.

Installation

npm install arrows-svg

How to use it

https://codesandbox.io/s/brave-haslett-tlmz7

import arrowCreate, { DIRECTION } from 'arrows-svg'

const arrow = arrowCreate({
  from: document.getElementById('from'),
  to: document.getElementById('to'),
})

/*
  - arrow.node is HTMLElement
  - remove arrow from DOM with arrow.clear()
*/
document.body.appendChild(arrow.node);

Arrow could be also created with window.arrowCreate() function.

CSS styles

Styles should be added to make arrow visible. Feel free to change them.

.arrow {
  pointer-events: none;
}

.arrow__path {
  stroke: #000;
  fill: transparent;
  stroke-dasharray: 4 2;
}

.arrow__head line {
  stroke: #000;
  stroke-width: 1px;
}

Example styles:

API

arrowCreate(props: IArrowProps): IArrow

interface IArrowProps {
  className?: string,
  head?: HeadFactory,
  from: Anchor,
  to: Anchor,
}

interface IArrow {
  node: DocumentFragment;
  clear: () => void;
}

* clear() - should be invoked to remove arrow.

Controlling arrow curve

import arrowCreate, { DIRECTION } from 'arrows-svg'

const arrow = arrowCreate({
  className: 'arrow',
  from: {
    direction: DIRECTION.TOP,
    node: document.getElementById('from'),
    translation: [-0.5, -1],
  },
  to: {
    direction: DIRECTION.RIGHT,
    node: document.getElementById('to'),
    translation: [0.9, 1],
  },
})

const DIRECTION = {
  TOP_LEFT: 'top-left',
  TOP: 'top',
  TOP_RIGHT: 'top-right',
  RIGHT: 'right',
  BOTTOM_LEFT: 'bottom-left',
  BOTTOM: 'bottom',
  BOTTOM_RIGHT: 'bottom-right',
  LEFT: 'left',
};

direction - position of Anchor in HTMLElement from/to.

type Anchor = {
  node: HTMLElement | (() => HTMLElement);
  direction: string;
  translation: PointArray; // e.g. [1, -0.5]
} | HTMLElement | (() => HTMLElement);

translation - is an array of two numbers [x, y] like [-0.5, 1.3] which are used by Bezier curve. x and y are offset multiplier of Bezier control point. Translation could be tested in examples/form/index.html

node - if HTMLElement still doesn't exist in DOM, try to pass it as a function () => node.

Custom head

example with diamond head

import arrowCreate, { DIRECTION, HEAD } from 'arrows-svg'

const arrow = arrowCreate({
  ...,
  head: HEAD.DIAMOND, // or { func: 'diamond' }
})

document.body.appendChild(arrow.node);

---

example with diamond head and specified size

import arrowCreate, { DIRECTION, HEAD } from 'arrows-svg'

const arrow = arrowCreate({
  ...,
  head: {
    func: HEAD.DIAMOND,
    size: 30, // custom options that will be passed to head function
  }
})

document.body.appendChild(arrow.node);

---

example with image head

import arrowCreate, { DIRECTION, HEAD } from 'arrows-svg'

const arrow = arrowCreate({
  ...,
  head: {
    func: HEAD.IMAGE, // could be just 'image' / 'IMAGE'
    width: 20, // px
    height: 30, // px
    image: 'abc.png', // url of image head
  }
})

document.body.appendChild(arrow.node);

---

Head types

* Default head size is 10
* Default head is thin
* head has also distance param, see more at https://codesandbox.io/s/damp-tdd-3fx91
* head could be also an array, see more at examples/heads_multiple

---

Custom head

import arrowCreate, { DIRECTION, HEAD } from 'arrows-svg'

const arrow = arrowCreate({
  ...,
  head: {
    func: ({ width }) => { // all passed props from head
      const SVG_NS = 'http://www.w3.org/2000/svg';
      const node = document.createElementNS(SVG_NS, 'g');

      // ... bla bla like node.setAttributeNS(...)

      return {
        node,
        width: width,
        height: 25,
      }

      // OR node could be string like

      return {
        node: '<rect x="-10" y="-10" width="20" height="25" />',
        width: size,
        height: size,
      }
    },
    width: 30,
  }
})

document.body.appendChild(arrow.node);

* Return of custom head function always require a params like { node, width, height }

Building

npm run build

Development

npm run start

Testing

npm run test

Examples

in ./examples directory