# react-native-view-shot

Snapshot a view and save to an image.

The image will be stored in a temporary file that will only exist for as long as the app is running.

## Getting started

```
npm install --save react-native-view-shot
```

### Mostly automatic installation

```
react-native link react-native-view-shot
```

### Manual installation

#### iOS

1. In XCode, in the project navigator, right click `Libraries` ➜ `Add Files to [your project's name]`
2. Go to `node_modules` ➜ `react-native-view-shot` and add `RNViewShot.xcodeproj`
3. In XCode, in the project navigator, select your project. Add `libRNViewShot.a` to your project's `Build Phases` ➜ `Link Binary With Libraries`
4. Run your project (`Cmd+R`)<

#### Android

1. Open up `android/app/src/main/java/[...]/MainActivity.java`
  - Add `import com.reactlibrary.RNViewShotPackage;` to the imports at the top of the file
  - Add `new RNViewShotPackage()` to the list returned by the `getPackages()` method
2. Append the following lines to `android/settings.gradle`:
  	```
  	include ':react-native-view-shot'
  	project(':react-native-view-shot').projectDir = new File(rootProject.projectDir, 	'../node_modules/react-native-view-shot/android')
  	```
3. Insert the following lines inside the dependencies block in `android/app/build.gradle`:
  	```
      compile project(':react-native-view-shot')
  	```

#### Windows

No support yet. Feel free to PR.

## Usage

```js
import { findNodeHandle } from "react-native";
import RNViewShot from "react-native-view-shot";

RNViewShot.takeSnapshot(findNodeHandle(aRef), {
  format: "jpeg",
  quality: 0.8
})
.then(
  uri => console.log("Image saved to", uri),
  error => console.error("Oops, snapshot failed", error)
);
```

## Example

[Checkout react-native-view-shot-example](https://github.com/gre/react-native-view-shot-example)

## Full API

### `RNViewShot.takeSnapshot(view, options)`

Returns a Promise of the image URI.

- **`view`** references to a React Native component.
- **`options`** may include:
 - **`width`** / **`height`** *(number)*: the width and height of the image to capture.
 - **`format`** *(string)*: either `png` or `jpg`/`jpeg` or `webm` (Android). Defaults to `png`.
 - **`quality`** *(number)*: the quality. 0.0 - 1.0 (default). (only available on lossy formats like jpeg)

## Notes

Snapshots are not guaranteed to be pixel perfect. It also depends on the platform. Here is some difference we have noticed and how to workaround.

- Support of special components like Video / GL views remains untested.
- It's preferable to **use a background color on the view you rasterize** to avoid transparent pixels and potential weirdness that some border appear around texts.

## Thanks

- To initial iOS work done by @jsierles in https://github.com/jsierles/react-native-view-snapshot
- To React Native implementation of takeSnapshot in iOS by @nicklockwood