React-medium-image-zoom-fork NPM

react-medium-image-zoom

This library is a React.js implementation of Medium.com's image zoom that allows for images to work together for a “zooming” effect and works regardless of parent elements that have overflow: hidden or parents with transform properties.

As an added bonus, it will let you zoom anything (see the Storybook Examples for more).

Blog post announcing v4

Installation

npm i react-medium-image-zoom

yarn add react-medium-image-zoom

<!-- this build only needs React to be already present -->
<script src="https://unpkg.com/react-medium-image-zoom"></script>

Basic Usage

Uncontrolled component (default)

Import the component and the CSS, wrap whatever you want to be "zoomable" with this component, and the component will handle it's own state:

import React from 'react'
import Zoom from 'react-medium-image-zoom'
import 'react-medium-image-zoom/dist/styles.css'

const MyComponent = () => (
  <Zoom>
    <img
      alt="that wanaka tree"
      src="/path/to/thatwanakatree.jpg"
      width="500"
    />
  </Zoom>
)

export default MyComponent

You can zoom anything, so <picture>, <figure>, and even <div> elements are all valid:

// <picture>
<Zoom>
  <picture>
    <source media="(max-width: 800px)" srcSet="/path/to/teAraiPoint.jpg" />
    <img
      alt="that wanaka tree"
      src="/path/to/thatwanakatree.jpg"
      width="500"
    />
  </picture>
</Zoom>

// <figure>
<figure>
  <Zoom>
    <img
      alt="that wanaka tree"
      src="/path/to/thatwanakatree.jpg"
      width="500"
    />
  </Zoom>
  <figcaption>That Wanaka Tree</figcaption>
</figure>

// <div> that looks like a circle
<Zoom>
  <div
    aria-label="A blue circle"
    style={{
      width: 300,
      height: 300,
      borderRadius: '50%',
      backgroundColor: '#0099ff'
    }}
  />
</Zoom>

Controlled component (`Controlled`)

Import the Controlled component and the CSS, wrap whatever you want to be "zoomable" with this component and then dictate the zoomed/unzoomed state to the component. Here, we will automatically zoom the component once the image has loaded:

import React, { useCallback, useState } from 'react'
import { Controlled as ControlledZoom } from 'react-medium-image-zoom'
import 'react-medium-image-zoom/dist/styles.css'

const MyComponent = () => {
  const [isZoomed, setIsZoomed] = useState(false)

  const handleImgLoad = useCallback(() => {
    setIsZoomed(true)
  }, [])

  const handleZoomChange = useCallback(shouldZoom => {
    setIsZoomed(shouldZoom)
  }, [])

  return (
    <ControlledZoom isZoomed={isZoomed} onZoomChange={handleZoomChange}>
      <img
        alt="that wanaka tree"
        onLoad={handleImgLoad}
        src="/path/to/thatwanakatree.jpg"
        width="500"
      />
    </ControlledZoom>
  )
)

export default MyComponent

The onZoomChange prop accepts a callback that will receive true or false based on events that occur (like click or scroll events) to assist you in determining when to zoom and unzoom the component.

There is also an example in the Storybook Examples of how to use a Controlled component to create a full-screen slideshow gallery.

API

Both uncontrolled & controlled components

You can pass these options to either the default or controlled components.

Prop	Type	Required	Default	Details
`closeText`	`String`	no	`'Unzoom Image'`	Accessible label text for when you want to unzoom
`openText`	`String`	no	`'Zoom Image'`	Accessible label text for when you want to zoom
`overlayBgColorEnd`	`String`	no	`'rgba(255, 255, 255, 0.95)'`	Modal overlay background color at end of zoom
`overlayBgColorStart`	`String`	no	`'rgba(255, 255, 255, 0)'`	Modal overlay background color at start of zoom
`portalEl`	`Element`	no	`document.body`	DOM Element to which we will append the zoom modal
`scrollableEl`	`Window`	no	`window`	DOM Element to which we will listen for scroll events to determine if we should unzoom
`transitionDuration`	`Number`	no	`300`	Transition duration in milliseconds for the component to use on zoom and unzoom. Set this to `0` to disable the animation
`wrapElement`	`String`	no	`'div'`	Wrapper element
`wrapStyle`	`Object`	no	`null`	Optional style object to pass to the wrapper element. Useful when you want the `<Zoom>` container to be `width: '100%'`, for example
`zoomMargin`	`Number`	no	`0`	Offset in pixels the zoomed image should be from the `window`' boundaries
`zoomZindex`	`Number`	no	`2147483647`	`z-index` value for the zoom overlay

Only the controlled component

You can pass these options to only the controlled component.

Prop	Type	Required	Default	Details
`isZoomed`	`bool`	yes	`false`	Tell the component whether or not it should be zoomed
`onZoomChange`	`Function`	no	`Function.prototype`	Listen for hints from the component about when you should zoom (`true` value) or unzoom (`false` value)

Migrating From v3 to v4

In v3, you might have code like this:

<ImageZoom
  image={{
    src: '/path/to/bridge.jpg',
    alt: 'Golden Gate Bridge',
    className: 'img',
    style: { width: '50em' }
  }}
  zoomImage={{
    src: '/path/to/bridge-big.jpg',
    alt: 'Golden Gate Bridge'
  }}
  zoomMargin={80}
/>

In v3, you would pass properties for your normal image that would be zoomed, and you would pass an optional zoomImage that would be a higher quality image that would replace the original image when zoomed.

The problem with v3 was that it tried to assume too many things about what it is you were trying to zoom, and this resulted in overly complex and near-unmaintainable code that had a number of bugs.

In v4, you can zoom the bridge example above like this:

<Zoom zoomMargin={40}>
  <img
    src="/path/to/bridge.jpg"
    alt="Golden Gate Bridge"
    className="img"
    style={{ width: '50em'}}
  />
</Zoom>

We've removed the zoomImage functionality (there is an issue for us to consider re-adding something like it), but as it was not a primary use case for many consumers, we opted to ship v4 without it.

Please see the Controlled component (Controlled) section for further documentation regarding controlled components that used the isZoomed, onZoom, and onUnzoom properties.