react-native-cached-image-viewer

react-native-cached-image-viewer

React native Cached Image Viewer component for react-native

I last used it on React Native v0.63.3

This project is not my owned project.
I modified tuananhluong's project. As i readed his page , he forked and modified
kfiroo's project.
ALSO. I copied the following texts from kfiroo/react-native-cached-image and made some changes

THANKS FOR kfiroo AND tuananhluong

WHY I MODIFIED

! react-native-fetch-blob is deprecated. I used rn-fetch-blob instead.
! @react-native-community/netinfo is changed some things.
! componentWillReceiveProps is deprecated. I changed to componentDidUpdate
! string ref's are deprecated. I changed to createRef()

This package is greatly inspired by @jayesbe's amazing react-native-cacheable-image but adds some functionality that we were missing when trying to handle caching images in our react-native app.

Installation

npm install react-native-cached-image-viewer --save
- or -
yarn add react-native-cached-image-viewer

We use rn-fetch-blob to handle file system access in this package and it requires an extra step during the installation.

You should only have to do this once.

react-native link rn-fetch-blob

Or, if you want to add Android permissions to AndroidManifest.xml automatically, use this one:

RNFB_ANDROID_PERMISSIONS=true react-native link rn-fetch-blob

Grant Permission to External storage for Android 5.0 or lower

The mechanism for granting Android permissions has slightly different since Android 6.0 released, please refer to Official Document.

If you're going to access external storage (say, SD card storage) for Android 5.0 (or lower) devices, you might have to add the following line to AndroidManifest.xml.

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.rnfetchblobtest"
    android:versionCode="1"
    android:versionName="1.0">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
+   <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+   <uses-permission android:name="android.permission.DOWNLOAD_WITHOUT_NOTIFICATION" />
    ...

Also, if you're going to use Android Download Manager you have to add this to AndroidManifest.xml

    <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
+           <action android:name="android.intent.action.DOWNLOAD_COMPLETE"/>
    </intent-filter>

If you are going to use the wifiOnly flag, you need to add this to AndroidManifest.xml

+   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    ...

Grant Access Permission for Android 6.0

Beginning in Android 6.0 (API level 23), users grant permissions to apps while the app is running, not when they install the app. So adding permissions in AndroidManifest.xml won't work for Android 6.0+ devices. To grant permissions in runtime, you might use PermissionAndroid API.

Usage

TODO - add usage example

import React, { Component } from 'react'
import { ActivityIndicator } from 'react-native'
import {
    CachedImage,
    ImageCacheProvider
} from 'react-native-cached-image-viewer';

const images = [
    'https://example.com/images/1.jpg',
    'https://example.com/images/2.jpg',
    'https://example.com/images/3.jpg',
    // ...
];

export default class Example extends Component {
    render() {
        return (
            <ImageCacheProvider
                urlsToPreload={images}
                onPreloadComplete={() => console.log('hey there')}>

                <CachedImage source={{uri: images[0]}}/>

                <CachedImage source={{uri: images[1]}}/>

				<CachedImage source={{uri: images[2]}}/>

                <CachedImage 
                    style={{
                        width : 40,
                        height : 40,
                    }} 
                    source={{uri: 'https://randomuser.me/api/portraits/women/60.jpg'}}
                    loadingIndicator={ActivityIndicator}
				/>

            </ImageCacheProvider>
        );
    }
}

Sorry if there is something unrelated to the text below. It may be saying something irrelevant or invalid because I copied this text and haven't checked it all

API

This package exposes 3 modules:

const {
    CachedImage,            // react-native component that is a drop-in replacement for your react-native `Image` components
    ImageCacheProvider,     // a top level component that provides accsess to the underlying `ImageCacheManager` and preloads images
    ImageCacheManager,      // the logic behind cache machanism - ttl, fs, url resolving etc. 
} = require('react-native-cached-image-viewer');

ImageCacheManager

This is where all the cache magic takes place. The API usually takes a URL and a set of ImageCacheManagerOptions.

ImageCacheManager.downloadAndCacheUrl(url: String, options: ImageCacheManagerOptions): Promise<String>

Check the cache for the the URL (after removing fixing the query string according to ImageCacheManagerOptions.useQueryParamsInCacheKey). If the URL exists in cache and is not expired, resolve with the local cached file path. Otherwise, download the file to the cache folder, add it to the cache and then return the cached file path.

ImageCacheManager.seedAndCacheUrl(url: String, seedPath: String, options: ImageCacheManagerOptions): Promise<String>

Check the cache for the the URL (after removing fixing the query string according to ImageCacheManagerOptions.useQueryParamsInCacheKey). If the URL exists in cache and is not expired, resolve with the local cached file path. Otherwise, copy the seed file into the cache folder, add it to the cache and then return the cached file path.

ImageCacheManager.deleteUrl(url: String, options: ImageCacheManagerOptions): Promise

Removes the cache entry for the URL and the local file corresponding to it, if it exists.

ImageCacheManager.clearCache(options: ImageCacheManagerOptions): Promise

Clear the URL cache and remove files in the cache folder (as stated in the ImageCacheManagerOptions.cacheLocation)

ImageCacheManager.getCacheInfo(options: ImageCacheManagerOptions): Promise.<{file: Array, size: Number}>

Returns info about the cache, list of files and the total size of the cache.

CachedImage

CachedImage is a drop in replacement for the Image component that will attempt to cache remote URLs for better performance.
It's main use is to hide the cache layer from the user and provide a simple way to cache images.
CachedImage uses an instance of ImageCacheManager to interact with the cache, if there is an instance provided by ImageCacheProvider via the context it will be used, otherwise a new instance will be created with the options from the component's props.

<CachedImage
    source={{
        uri: 'https://example.com/path/to/your/image.jpg'
    }}
    style={styles.image}
/>

Props

• renderImage - a function that returns a component, used to override the underlying Image component.
• activityIndicatorProps - props for the ActivityIndicator that is shown while the image is downloaded.
• defaultSource - prop to display a background image while the source image is downloaded. This will work even in android, but will not display background image if there you set borderRadius on this component style prop
• loadingIndicator - component prop to set custom ActivityIndicator.
• fallbackSource - prop to set placeholder image. when source.uri is null or cached failed, the fallbackSource will be display.
• any of the ImageCacheManagerOptionsPropTypes props - customize the ImageCacheManager for this specific CachedImage instance.

ImageCacheProvider

This is a top-level component with 2 major functions:

1. Provide the customized ImageCacheManager to nested CachedImage.
2. Preload a set of URLs.

Props

• urlsToPreload - an array of URLs to preload when the component mounts. default []
• numberOfConcurrentPreloads - control the number of concurrent downloads, usually used when the urlsToPreload array is very big. default urlsToPreload.length
• onPreloadComplete - callback for when the preload is complete and all images are cached.

ImageCacheManagerOptions

A set of options that are provided to the ImageCacheManager and provide ways to customize it to your needs.

type ImageCacheManagerOptions = {
    headers: PropTypes.object,                      // an object to be used as the headers when sending the request for the url. default {}
    
    ttl: PropTypes.number,                          // the number of seconds each url will stay in the cache. default 2 weeks
    
    useQueryParamsInCacheKey: PropTypes.oneOfType([ // when handling a URL with query params, this indicates how it should be treated:
        PropTypes.bool,                             // if a bool value is given the whole query string will be used / ignored
        PropTypes.arrayOf(PropTypes.string)         // if an array of strings is given, only these keys will be taken from the query string.
    ]),                                             // default false
    
    cacheLocation: PropTypes.string,                // the path to the root of the cache folder. default the device cache dir 
    
    allowSelfSignedSSL: PropTypes.bool,             // true to allow self signed SSL URLs to be downloaded. default false
};

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.