bpk-component-nudger

bpk-component-nudger

Backpack nudger component.

Installation

npm install bpk-component-nudger --save-dev

Usage

BpkNudger

import React, { Component } from 'react';
import BpkLabel from 'bpk-component-label';
import BpkNudger from 'bpk-component-nudger';

class App extends Component {
  constructor() {
    super();

    this.state = {
      value: 1,
    };
  }

  handleChange = value => {
    this.setState({ value });
  };

  render() {
    return (
      <div>
        <BpkLabel htmlFor="my-nudger">Number of passengers</BpkLabel>
        <BpkNudger
          id="my-nudger"
          min={1}
          max={10}
          value={this.state.value}
          onChange={this.handleChange}
          decreaseButtonLabel="Decrease"
          increaseButtonLabel="Increase"
        />
      </div>
    );
  }
}

BpkConfigurableNudger

import React, { Component } from 'react';
import BpkLabel from 'bpk-component-label';
import { BpkConfigurableNudger } from 'bpk-component-nudger';

const options = ['economy', 'premium', 'business', 'first'];

const compareValues = (value1, value2) => {
    const [aIndex, bIndex] = [options.indexOf(value1), options.indexOf(value2)];
    return aIndex - bIndex;
  };

const incrementValue = currentValue => {
    const [aIndex] = [options.indexOf(currentValue) + 1];
    return options[aIndex];
  };

const decrementValue = currentValue => {
    const [aIndex] = [options.indexOf(currentValue) - 1];
    return options[aIndex];
  };

const formatValue = currentValue => currentValue.toString();

class App extends Component {
  constructor() {
    super();

    this.state = {
      value: 1,
    };
  }

  handleChange = value => {
    this.setState({ value });
  };

  render() {
    return (
      <div>
        <BpkLabel htmlFor="nudger">Number of passengers</BpkLabel>
        <BpkConfigurableNudger
          id="nudger"
          min="economy"
          max="first"
          value={this.state.value}
          onChange={this.handleChange}
          decreaseButtonLabel="Decrease"
          increaseButtonLabel="Increase"
          compareValues={compareValues}
          incrementValue={incrementValue}
          decrementValue={decrementValue}
          formatValue={formatValue}
        />
      </div>
    );
  }
}

Props

BpkNudger

Property	PropType	Required	Default Value
id	string	true	-
decreaseButtonLabel	string	true	-
increaseButtonLabel	string	true	-
max	number	true	-
min	number	true	-
onChange	func	true	-
value	number	true	-
className	string	false	null
buttonType	oneOf('secondary', 'secondaryOnDark')	false	secondary

BpkConfigurableNudger

Property	PropType	Required	Default Value
id	string	true	-
decreaseButtonLabel	string	true	-
increaseButtonLabel	string	true	-
max	number	true	-
min	number	true	-
onChange	func	true	-
value	number	true	-
compareValues	func	true	-
incrementValue	func	true	-
decrementValue	func	true	-
formatValue	func	true	-
className	string	false	null
inputClassName	string	false	null
buttonType	oneOf('secondary', 'secondaryOnDark')	false	secondary

compareValues

Given a and b:

• If a is less than b then compareValues(a, b) should return a value less than 0
• If a and b are equal then compareValues(a, b) should return exactly 0
• If a is greater than b then compareValues(a, b) should return a value greater than 0

We use this along with the min and max values to determine when we should disable the increment and decrement buttons. This is inspired by the compareFunction in Array.prototype.sort

For integer numbers the following is a correct implementation const compareValues = (a: number, b: number): number => a - b;

incrementValue & decrementValue

Functions that handle the incrementing or decrementing of the current selected value.

formatValue

A simple function that will allow you to set the format of the display value e.g. local dates or times.

Theme Props

Same as secondary button