react-native-image-resizer/README.md

# React Native Image Resizer

A React Native module that can create scaled versions of local images (also supports the assets library on iOS).

## Setup

First, install the package:
```
npm install react-native-image-resizer
```

Then, follow those instructions:

### iOS

You need to add `RNImageResizer.xcodeproj` to **Libraries** and add `libRNImageResizer.a` to **Link Binary With Libraries** under **Build Phases**. [More info and screenshots about how to do this is available in the React Native documentation](http://facebook.github.io/react-native/docs/linking-libraries-ios.html#content).

### Android

#### Update your gradle files

For **react-native >= v0.15**, this command will do it automatically:
```
react-native link react-native-image-resizer
```

For **react-native = v0.14**
You will have to update them manually:

In `android/settings.gradle`, add:
```
include ':react-native-image-resizer'
project(':react-native-image-resizer').projectDir = new File(settingsDir, '../node_modules/react-native-image-resizer/android')
```

In `android/app/build.gradle` add:
```
dependencies {
  ...
  compile project(':react-native-image-resizer')
}
```

#### Register the package into your `MainActivity`
```java
package com.example;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;

import com.facebook.react.LifecycleState;
import com.facebook.react.ReactInstanceManager;
import com.facebook.react.ReactRootView;
import com.facebook.react.modules.core.DefaultHardwareBackBtnHandler;
import com.facebook.react.shell.MainReactPackage;
import com.facebook.soloader.SoLoader;

// IMPORT HERE
import fr.bamlab.rnimageresizer.ImageResizerPackage;
// ---

public class MainActivity extends Activity implements DefaultHardwareBackBtnHandler {

    private ReactInstanceManager mReactInstanceManager;
    private ReactRootView mReactRootView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mReactRootView = new ReactRootView(this);

        mReactInstanceManager = ReactInstanceManager.builder()
                .setApplication(getApplication())
                .setBundleAssetName("index.android.bundle")
                .setJSMainModuleName("index.android")
                .addPackage(new MainReactPackage())

                // REGISTER PACKAGE HERE
                .addPackage(new ImageResizerPackage())
                // ---
                .setUseDeveloperSupport(BuildConfig.DEBUG)
                .setInitialLifecycleState(LifecycleState.RESUMED)
                .build();

        mReactRootView.startReactApplication(mReactInstanceManager, "example", null);

        setContentView(mReactRootView);
    }

    ...
```

## Usage example

```javascript
var ImageResizer = require('react-native-image-resizer');

ImageResizer.createResizedImage(imageUri, newWidth, newHeight, compressFormat, quality).then((resizedImageUri) => {
  // resizeImageUri is the URI of the new image that can now be displayed, uploaded...
});
```

## API

### `promise createResizedImage(path, maxWidth, maxHeight, compressFormat, quality, rotation = 0)`

Open the image at the given path and resize it so that it is less than the specified `maxWidth` and `maxHeight` (i.e: ratio is preserved). `compressFormat` is either `JPEG`, `PNG` (android only) or `WEBP` (android only).

`quality` is a number between 0 and 100, used for the JPEG compression.

`rotation` is the rotation to apply to the image, in degrees, for android only. On iOS, the resizing is done such that the orientation is always up.

The promise resolves with a string containing the uri of the new file.