Table of contents

• Table of contents
• react-file-viewer
  • Supported file formats:
  • Usage
  • Development
    • To start demo app
    • Testing
    • To run the linter
    • Extending the file viewer
    • Viewing local changes in a secondary repo
    • Testing locally against the mymove application
  • Roadmap

react-file-viewer

Extendable file viewer for web

Forked from https://github.com/plangrid/react-file-viewer

Supported file formats:

• Images: png, jpeg, gif, bmp, including 360-degree images
• pdf
• csv
• xslx
• docx
• Video: mp4, webm
• Audio: mp3

Usage

Note this module works best with react 16+. If you are using React < 16 you will likely need to use version 0.5. npm install react-file-viewer@0.5.0.

There is one main React component, FileViewer, that takes the following props:

fileType string: type of resource to be shown (one of the supported file formats, eg 'png'). Passing in an unsupported file type will result in displaying an unsupported file type message (or a custom component).

filePath string: the url of the resource to be shown by the FileViewer.

onError function [optional]: function that will be called when there is an error in the file viewer fetching or rendering the requested resource. This is a place where you can pass a callback for a logging utility.

errorComponent react element [optional]: A component to render in case of error instead of the default error component that comes packaged with react-file-viewer.

unsupportedComponent react element [optional]: A component to render in case the file format is not supported.

To use a custom error component, you might do the following:

// MyApp.js
import React, { Component } from 'react';
import logger from 'logging-library';
import FileViewer from 'react-file-viewer';
import { CustomErrorComponent } from 'custom-error';

const file = 'http://example.com/image.png'
const type = 'png'

class MyComponent extends Component {
  render() {
    return (
      <FileViewer
        fileType={type}
        filePath={file}
        errorComponent={CustomErrorComponent}
        onError={this.onError}/>
    );
  }

  onError(e) {
    logger.logError(e, 'error in file-viewer');
  }
}

Development

There is a demo app built into this library that can be used for development purposes. It is by default served via webpack-dev-server.

To start demo app

yarn serve:dev will start the webpack analyzer and serve app.js for debugging and playwright.

Testing

Tests use Jest, Enzyme, and Playwright.

Run tests with:

yarn test:watch

This starts Jest in watch mode. To run a particular test file, while in watch mode hit p and then type the path or name of the file.

Some tests use snapshots. If intended changes to a component cause snapshot tests to fail, snapshot files need to be updated (stored in __snapshots__ directories). To do this run:

yarn jest --updateSnapshot

yarn test:e2e

This runs the playwright tests for the drivers. As certain drivers now rely on modern web API, playwright must be used to simulate a real browser environment as this is still experimental within Jest's JSDOM.

To run the linter

yarn lint

Extending the file viewer

Adding supported file types is easy (and pull requests are welcome!). Say, for example, you want to add support for .rtf files. First, you need to create a "driver" for that file type. A driver is just a component that is capable of rendering that file type. (See what exists now in src/components/drivers.) After you've created the driver component and added it to src/components/drivers, you simply need to import the component into file-vewer.jsx and add a switch clause for rtf to the getDriver method. Ie:

case 'rtf':
  return RtfViewer;

Viewing local changes in a secondary repo

If you are working on a feature branch and need to see changes introduced in that branch in another repo that using this library, here are the steps:

1. Run yarn build in this react-file-viewer repo
2. In the secondary repo, update package.json to point the trussworks/react-file-viewer declaration to your branch in the react-file-viewer repo:

"@trussworks/react-file-viewer": "git+https://github.com/trussworks react-file-viewer#your-branch-name"

3. In the secondary repo, reinstall frontend packages and then run the client.

4. When your react-file-viewer branch is merged into main, update the package.json in the secondary repo to declare the react-file-viewer libary normally

"@trussworks/react-file-viewer": "git+https://github.com/trussworks react-file-viewer"

Testing locally against the mymove application

Testing locally against the mymove application can be done via yarn link, but for the purpose of being thorough it is recommended to manually test against the /dist/ output. This verifies the webpack is successfully compiling/transpiling and that the mymove application is successfully serving chunks.

TODO: ENHANCE ME (This is supposed to work, but it doesn't. Fallback is still rm -rf node_modules && yarn install && ./scripts/copy-react-file-viewer && make client_run)

1. [OPTIONAL] Within this repository, navigate to webpack.config.js. This is the production webpack.
   1. Find where plugins: [new BundleAnalyzerPlugin({ analyzerMode: 'disabled' })] is located and remove/enable the analyzerMode attribute
   2. This makes it so you can preview the chunks
2. Within this repository, run yarn build, it should output new files to /dist/
3. Within the MyMove repository update package.json and set "@transcom/react-file-viewer" to point to the local location of this repository: Such as "file:../react-file-viewer"
4. Within MyMove, run yarn upgrade @transcom/react-file-viewer
5. Within MyMove, run ./scripts/copy-react-file-viewer

You should now successfully be testing the webpack build of react-file-viewer against MyMove. Each time you adjust react-file-viewer, repeat steps 2, 4, and 5 to reflect within MyMove.

The benefit of working this way over yarn link is that we can properly simulate MyMove serving the chunks from its ./scripts/copy-react-file-viewer.

Roadmap

• Remove ignored linting rules and fix them
• Convert CSS to CSS modules
• Add support for custom controls components
• Convert to TypeScript
• Add caching to fetch wrapper?
• Fix re-render FileViewer if file changes
• Code split drivers to reduce bundle size
• Update PDF.JS & API & use worker loader