dv-scalebar

comes in two flavours -
As a framework-agnostic web component, and as a Vue component with minimal overhead.

Documentation with live examples

Getting Started

The scalebar component is cross-built as a framework-agnostic web component created with Lit and as a framework-specific Vue component. The Lit version is compatible with any framework, vanilla JS, or plain HTML, with a size of approximately 69kB (26kB gzip). The Vue version, on the other hand, can only be used in Vue projects but is lighter at around 51kB (20kB gzip) and is more versatile.

These sizes include dv-scalebar's only dependency, chroma.js

Smaller builds without dependencies

For projects where chroma.js is already in use, builds of the scalebar component that exclude this dependency are available. This reduces its size significantly, to about 26kB (9kB gzip) for the Lit version and 9kB (3kB gzip) for the Vue version.

Intallation

$ npm install dv-scalebar

Lit

The Lit version of the component is highly versatile and can be used in various environments; with or without a framework, and with or without a bundler. Typically, you only need to import the component in JavaScript...

import "dv-scalebar/lit"

...and then use it in the HTML.

<dv-scalebar colors labels ticks></dv-scalebar>

Vue

In Vue, the use of Single File Components (SFCs, or .vue files) is quite common. To use dv-scalebar in an SFC, import it in the <script> section before referencing it in the <template> or render function.

The dv-scalebar/sfc path targets an SFC version that uses TypeScript and includes scoped styles. Alternatively, you can import the pre-built Vue component from dv-scalebar/vue and separately import the style file.

<script setup lang="ts">
import dvScalebar from "dv-scalebar/sfc"
//import dvScalebar from "dv-scalebar/vue"
//import "dv-scalebar/style.css"
</script>

<template>
  <dv-scalebar colors labels ticks/>
</template>

Reactivity

The following example demonstrates the binding of reactive variables to attributes of the scalebar component in Vue:

<script setup lang="ts">
import { ref } from 'vue';
import dvScalebar from 'dv-scalebar/sfc'

// calls a function periodiclly with a random integer
const intervalRandom = (fn: (r: number) => void, r: number, ms: number) =>
  setInterval(() => fn(Math.floor(Math.random() * r)), ms)

const COLORS = ["OrRd","PuBu","BuPu","BuGn","YlOr","YlGn","RdPu","YlGn"];

// reactive variables
const num = ref(0); 
const col = ref(COLORS[0]);

// run intervals
intervalRandom(r => num.value = r, 10, 500);
intervalRandom(r => col.value = COLORS[r], COLORS.length, 700);
</script>

<template>
  <dv-scalebar :colors="col" :ticks="num" labels />
</template>

The use of multiple attributes in the above example can be simplified with v-bind like so...

<template>
  <dv-scalebar v-bind={colors:col, ticks:num, labels:true} />
</template>

... or even with a single reactive configuration object:

<script setup lang="ts">
/* .... */

// reactive variable
const sb = ref({colors:COLORS[0],ticks:0,labels:true}); 

// run intervals
intervalRandom(r => sb.value.ticks = r, 10, 500);
intervalRandom(r => sb.value.colors = COLORS[r], COLORS.length, 700);
</script>

<template>
  <dv-scalebar v-bind="sb"></dv-scalebar>
</template>

Usage

This page demonstrates some basic attributes that can be used to modify the scalebar component. For more detailed examples, refer to the sections in the side navigation.

"Hello World" Example

Without any attributes, the scalebar renders as a simple grayscale gradient.

Code

<dv-scalebar></dv-scalebar>

Results

"Real World" Examples

The scalebar can be enhanced with basic attributes such as colors, labels, ticks, and classes, as well as layout properties like vertical, reverse, and before/after.

Code

<dv-scalebar colors="Viridis" labels="0,2,4,6,8,10" ticks="11"></dv-scalebar>
<dv-scalebar colors="Viridis" labels="low,medium,high" classes ticks></dv-scalebar>
<dv-scalebar colors="piYG" before="slategray" labels ticks="5"></dv-scalebar>
<dv-scalebar colors="piYG" labels="min,-1σ,0,1σ,max" classes="0,.16,.5,.84,1" ticks></dv-scalebar>

<dv-scalebar vertical colors="PuBuGn" labels ticks="0,.1,.3,.6,1"></dv-scalebar>
<dv-scalebar vertical colors="YlGnBu" labels="low,medium,high" classes="0,.16,.84,1" ticks></dv-scalebar>
<dv-scalebar vertical colors="BrBG" reverse labels="-80,-40,0,70,140" ticks="9"></dv-scalebar>
<dv-scalebar vertical colors="dodgerblue,orangered" reverse labels="6°,10°,20°,27°" ticks="0,.19,0.66,1" before after></dv-scalebar>

Results

Colors

Code

<dv-scalebar colors></dv-scalebar>
<dv-scalebar colors="teal"></dv-scalebar>
<dv-scalebar colors="rgb(70 100 250 / .5)"></dv-scalebar>
<dv-scalebar colors="yellow,red,black"></dv-scalebar>
<dv-scalebar colors="Viridis"></dv-scalebar>

Results

Labels

Code

<dv-scalebar colors="OrRd" labels></dv-scalebar>
<dv-scalebar colors="OrRd" labels="9"></dv-scalebar>
<dv-scalebar colors="OrRd" labels="zero,50,1e2"></dv-scalebar>

Results

Ticks

Code

<dv-scalebar colors="PuOr" ticks></dv-scalebar>
<dv-scalebar colors="PuOr" ticks="11"></dv-scalebar>
<dv-scalebar colors="PuOr" ticks="0,.1,.3,.6,1"></dv-scalebar>

Results

Classes

Code

<dv-scalebar colors="orange,snow,teal" classes></dv-scalebar>
<dv-scalebar colors="orange,snow,teal" classes="9"></dv-scalebar>
<dv-scalebar colors="orange,snow,teal" classes="0,.1,.3,.6,1"></dv-scalebar>

Results

More

This was a brief overview of the four most common attributes. They are explained in more detail in the Documentation, along with additional layout and color attributes.