@halka/react-medium-zoom

A thin wrapper on top of the amazing Medium Zoom

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Why the wrapper?

Got tired of re-writing this component everywhere. It tried to strike the right balance between the declarative goodness and imperative power.

Feel free to star the repo, fork the repo and raise issues

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Installation

npm i @halka/react-medium-zoom

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API Reference

<MediumZoom> component

The easiest way to consume this package is using the MediumZoom component

import { MediumZoom } from '@halka/react-medium-zoom';

function App() {
  return (
    <div>
      <OtherComponents >
      <MediumZoom
        /** you can also attach a ref and it will be refer to the <img> element underneath
        /** any valid <img /> props **/
        src={imgUrl}
        alt="image"
        style={{ width: 'auto', height: 400 }}
        /** anything you can pass to medium zoom options **/
        options={{ background: 'black', margin: 20 }}
      />
      <OtherComponents >
    </div>
  );
}

Props

• All the base <img /> props like src, alt (don't forget alt), etc.
• You can also use ref to attach a ref to the original <img> component
• options - An object that accepts all the options accepted by medium-zoom. Reference docs
• You can also add data-zoom-src to add a higher quality image for the zoomed view. Reference docs

Supported Options

Property	Type	Default	Description
margin	number	0	The space outside the zoomed image
background	string	"#fff"	The background of the overlay
scrollOffset	number	40	The number of pixels to scroll to close the zoom
container	string | HTMLElement | object	null	The viewport to render the zoom in Read more →
template	string | HTMLTemplateElement	null	The template element to display on zoom Read more →

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useMediumZoom hook

If you want more control over the interaction, you can use the hook as well.

import { useMediumZoom } from '@halka/react-medium-zoom';

function Image(props) {
  const ref = React.useRef();
  const handler = useMediumZoom(ref, {
    background: 'black',
  });

  return (
    <div>
      <button
        onClick={() => {
          handler.open();
        }}
      >
        Open Image
      </button>
      <img ref={ref} src={imgUrl} alt="image" />
    </div>
  );
}

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Arguments

• ref - first arguments is the ref object of the <img> element to attach to.
• options - second is the options object accepted by medium-zoom. Reference docs

The hook returns the handler object which exposes a subset of the methods present on zoom instance.

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handler object

We strongly recommend not using the imperative methods on the zoom instance directly and use the methods exposed on the handler object instead.

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open(): Promise<void>

Opens the zoom and returns a promise resolving with the zoom.

handler.open();

Emits an event open on animation start and opened when completed.

Reference docs

Note: the return type is void instead of the zoom instance and it doesn't accept a target

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close(): Promise<void>

Closes the zoom and returns a promise resolving with the zoom.

handler.close();

Emits an event close on animation start and closed when completed.

Reference docs

Note: the return type is void instead of the zoom instance

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toggle(): Promise<void>

Opens the zoom when closed / dismisses the zoom when opened, and returns a promise resolving with the zoom.

handler.toggle();

Reference docs

Note: the return type is void instead of the zoom instance and it doesn't accept a target.

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on(type: string, listener: () => void, options?: boolean | AddEventListenerOptions): void

Registers the listener on each target of the zoom.

The same options as addEventListener are used.

handler.on('closed', event => {
  // the image has been closed
});

handler.on(
  'open',
  event => {
    // the image has been opened (tracked only once)
  },
  { once: true }
);

Reference docs

Note: the return type is void instead of the zoom instance

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off(type: string, listener: () => void, options?: boolean | AddEventListenerOptions): void

Removes the previously registered listener on each target of the zoom.

The same options as removeEventListener are used.

function listener(event) {
  // ...
}

handler.on('open', listener);
// ...
handler.off('open', listener);

Reference docs

Note: the return type is void instead of the zoom instance

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Supported Events

Event	Description
open	Fired immediately when the open method is called
opened	Fired when the zoom has finished being animated
close	Fired immediately when the close method is called
closed	Fired when the zoom out has finished being animated
detach	Fired when the detach method is called
update	Fired when the update method is called

Reference docs

Example and Advance Usage

• /examples/Image.tsx - showcases some advance usecases using the useMediumZoom hook. It shows usage of handler object, adding custom event listeners and using template.

You can also refer to examples in medium-zoom repo and try to implement using them the ways shown in the example component mentioned above.