React DS

Tiny (7KB) React Drag-to-Select component (with no dependencies! with support for touch devices!

I wrote this library because I couldn't find any existing one to do selections without having to wrap the items in their component.

In some cases you really need an unobtrusive way to make items selectable, this will do just that.

Installation

$ npm i react-ds

Or if you prefer yarn

console
$ yarn add react-ds

Usage

import Selection from 'react-ds';

// target (ref) is the parent component (so that selects only happen when clicking and dragging on it)
// elements (refs[]) is an array of refs to the components that are selectable

Props

target

Element where the selection should be applied to. This is to scope the mouse/touch event handlers and make sure that it doesn't affect your whole web app.

It must be a React

ref

Selection

elements

Array of refs to the elements that are selectable. The

Selection

The should exist before rendering the

Selection

onSelectionChange

Function that will be executed when the selection changes. An array of element indexes will be passed (with the same indexes as the

elements

This is where you want to update your state, to highlight them as selected for example.

onHighlightChange

While dragging,

onHighlightChange

When the mouse is released, it will be called with an empty array.

offset

(Optional)

This is used to calculate the coordinates of the mouse when drawing the Selection box, since the mouse events gives coordinates relative to the document, but the Selection box may have a different parent.

Essentially you need to pass the offset of the parent element where the Selection is being rendered. If it's rendered in the same component as the items to be selected then the default value will work fine.

If passing your own offset keep in mind that

getBoundingClientRect()

const boundingBox = target.getBoundingClientRect();
const offset = {
  top: boundingBox.top + window.scrollY,
  left: boundingBox.left + window.scrollX,
};

style

(Optional)

If you want to override the styles for the selection area, you can either pass any styles here, or use css and declare any styles on the

.react-ds-border

The styles are merged, so you can override just one property if you need (typically the

zIndex

The default styles are:

const style = {
  position: 'absolute',
  background: 'rgba(159, 217, 255, 0.3)',
  border: 'solid 1px rgba(123, 123, 123, 0.61)',
  zIndex: 9,
  cursor: 'crosshair',
}

ignoreTargets

(Optional)

Specify an array of CSS3 selectors for DOM targets that should be ignored when initiating a selection. i.e.

['div', 'div > p', '#someId']

This is specially useful because

react-ds

uses native browser events that bypass React's event queue, so you won't be able to

stopPropagation

as usual.

Example

This example was taken from

example/app/src/Example.js

import React from 'react';
import PropTypes from 'prop-types';
import Selection from 'react-ds';

export default class Example extends React.PureComponent {
  constructor() {
    super();
this.state = {
  ref: null,
  elRefs: [],
  selectedElements: [], // track the elements that are selected
};
  }
  handleSelection = (indexes) => {
    this.setState({
      selectedElements: indexes,
    });
  };
  getStyle = (index) => {
    if (this.state.selectedElements.indexOf(index) > -1) {
      // Selected state
      return {
        background: '#2185d0',
        borderColor: '#2185d0',
        color: 'white',
      };
    }
    return {};
  };
  addElementRef = (ref) => {
    const elRefs = this.state.elRefs;
    elRefs.push(ref);
    this.setState({
      elRefs,
    });
  };
  renderSelection() {
    if (!this.state.ref || !this.state.elRefs) {
      return null;
    }
    return (
      
    );
  }
  render() {
    const selectableElements = [
      'one',
      'another',
      'hey there',
      'item',
      'two',
      'three',
      'something longer?',
      'last'
    ];
    return (
      
 { this.setState({ ref }); } } className='item-container'>
        { selectableElements.map((el, index) => (
          

            { el }
          
        )) }
        { this.renderSelection() }
      
    );
  }
}

Example.PropTypes = {
  style: PropTypes.object,
};

Contributing

Only edit the files in the

src

dist

To run the tests simply run

npm test

test

{string}.test.js

Meta

Copyright © Alejandro U. Alvarez 2017. MIT Licensed.