upload-preview

Upload Preview

Preview component to show image or video being uploaded.

By default, will present a preview of the file being uploaded in case its an image or video.

The best place to get started is at our: React-Uploady Documentation Website

Installation

#Yarn: 
   $ yarn add @rpldy/uploady @rpldy/upload-preview 

#NPM:
   $ npm i @rpldy/uploady @rpldy/upload-preview 

Props

Name (* = mandatory)	Type	Default	Description
loadFirstOnly	boolean	false	load preview only for the first item in a batch
maxPreviewImageSize	number	2e+7	maximum size of image to preview
maxPreviewVideoSize	number	1e+8	maximum size of video to preview
fallbackUrl	string | FallbackMethod	undefined	static URL or function that returns fallback in case failed to load preview or when file over max size
imageMimeTypes	string[]	see list below	image mime types to load preview for
videoMimeTypes	string[]	see list below	video mime types to load preview for
previewComponentProps	PreviewComponentPropsOrMethod	undefined	object or function to generate object as additional props for the preview component
PreviewComponent	React.ComponentType<any>	img | video	The component that will show the preview
rememberPreviousBatches	boolean	false	show previous batches' previews as opposed to just the last
previewMethodsRef	React Ref	undefined	ref will be set with preview helper methods
onPreviewsChanged	(PreviewItem[]) => void	undefined	callback will be called whenever preview items array changes

Usage

import React from "react";
import Uploady from "@rpldy/uploady";
import UploadPreview from "@rpldy/upload-preview";

export const App = () => (
     <Uploady destination={{ url: "my-server.com/upload" }}>     
        <UploadPreview
            fallbackUrl="https://icon-library.net/images/image-placeholder-icon/image-placeholder-icon-6.jpg"/>
    </Uploady>
);

Advanced Usage

The props rememberPreviousBatches, previewMethodsRef, and onPreviewsChanged make it possible to do more with previews. Specifically, the make it possible to create a visual queue of the uploads.

This is especially useful when adding other features such as abort and retry.

The code below shows how to clear the previews with a button click:

import React from "react";
import Uploady, { useAbortItem } from "@rpldy/uploady";
import UploadPreview from "@rpldy/upload-preview";
import UploadButton from "@rpldy/upload-button";

const PreviewsWithClear = () => {
	const abortItem = useAbortItem();
	const previewMethodsRef = useRef();
	const [previews, setPreviews] = useState([]);

	const onPreviewsChanged = useCallback((previews) => {
		setPreviews(previews);
	}, []);

	const onClear = useCallback(() => {
		if (previewMethodsRef.current?.clear) {
			previewMethodsRef.current.clear();
		}
	}, [previewMethodsRef]);

	const onRemoveItem = useCallback(() => {
		if (previewMethodsRef.current?.removePreview) {
			abortItem("item-123"); //cancel the upload for the item
            previewMethodsRef.current.removePreview("item-123") //need the item id to remove the preview
        }
    }, [previewMethodsRef]);
	
	return <>
		<button onClick={onClear}>
            Clear {previews.length} previews
        </button>
		<br/>		
        <UploadPreview
            rememberPreviousBatches            
            previewMethodsRef={previewMethodsRef}
            onPreviewsChanged={onPreviewsChanged}
        />            		
	</>;
};

export const App = () => {	
	return <Uploady destination={{ url: "my-server.com/upload" }}>
		<UploadButton />
		<PreviewsWithClear />
	</Uploady>;
};

previewMethodsRef

type PreviewMethods = {
    clear: () => void;
    removePreview: (id: string) => void;
};

Provides access to preview related methods:

• clear - will reset all items shown in the preview
• removePreview - will remove a single item preview

These methods do not remove the item from the upload queue. ONLY from the preview.

Custom Preview Component

The Upload Preview can be customized in several ways. The main method is through the PreviewComponent prop. Passing a custom component will make the preview render your own UI per each file being uploaded.

The custom component is called with the following props

type PreviewProps = {
	id: string;
	url: string;
	name: string;
	type: PreviewType;
	isFallback: boolean;
    removePreview: () => void;
};

For an example of using a custom preview component see this story.

Custom Batch Items Method

The default way the UploadPreview component learns which items to show previews for is done by internally using the useBatchStartListener hook. This means that for a batch that hasn't started uploading, because a previous batch hasn't finished or when autoUpload = false, the previews for the next batch will not be shown.

If there's a different event (or one completely custom) you want to listen to, for example: the useBatchAddListener hook, you can do that with getUploadPreviewForBatchItemsMethod. With useBatchAddListener, the previews will be shown even for batches that hadn't started to upload yet.

This method expects a hook method as a parameter that will return a batch(-like) object with a items property as an array of BatchItems. It returns a UploadPreview component that will use the custom hook method to learn about the items to preview.

Below is an example of how to use it:

import React from "react";
import Uploady, { useBatchAddListener } from "@rpldy/uploady";
import { getUploadPreviewForBatchItemsMethod } from "@rpldy/upload-preview";
import UploadButton from "@rpldy/upload-button";

const MyUploadPreview = getUploadPreviewForBatchItemsMethod(useBatchAddListener);

export const App = () => {
    return (
        <Uploady
            destination={{ url: "[upload-url]" }}
        >
            <div className="App">
                <UploadButton>Upload Files</UploadButton>
                <br />
  
                <MyUploadPreview
                    maxPreviewVideoSize={2}
                    fallbackUrl="https://icon-library.net/images/image-placeholder-icon/image-placeholder-icon-6.jpg"
                />
            </div>
        </Uploady>
    );
}

Custom Previews Render

The UploadPreview component allows for a lot of customization by providing your own component to render each single preview. This is mostly enough since it doesn't render anything else beyond the preview items - no surrounding element/component.

However, in case you wish even more control, you can create your own hook from the batch method you wish to use (typically either useBatchAddListener or useBatchStartListener).

import { useBatchAddListener } from "@rpldy/uploady";
import { getPreviewsLoaderHook } from "@rpldy/upload-preview";

const useBatchAddPreviewsData = getPreviewsLoaderHook(useBatchAddListener);

const PreviewDataCustomerViewer = () => {
    const { previews } = useBatchAddPreviewsData({ rememberPreviousBatches: true });

    return previews.map((p) =>
        <div key={p.id}>
            {p.name}
            <img src={p.url}/>
        </div>);
};

The hook receives PreviewOptions and can also be called without any param.

Default image types

• "image/jpeg"
• "image/webp"
• "image/gif"
• "image/png"
• "image/apng"
• "image/bmp"
• "image/x-icon"
• "image/svg+xml"

Default video types

• "video/mp4"
• "video/webm"
• "video/ogg"