react-native-camera/README.md

react-native-camera

A camera module for React Native.

Known Issues

Below is a list of known issues. Pull requests are welcome for any of these issues!

• Orientation is not set correctly upon device rotation
• Stills captured to disk will not be cleaned up and thus must be managed manually for now

Getting started

1. npm install react-native-camera@latest --save
2. In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
3. Go to node_modules ➜ react-native-camera and add RCTCamera.xcodeproj
4. In XCode, in the project navigator, select your project. Add libRCTCamera.a to your project's Build Phases ➜ Link Binary With Libraries
5. Click RCTCamera.xcodeproj in the project navigator and go the Build Settings tab. Make sure 'All' is toggled on (instead of 'Basic'). Look for Header Search Paths and make sure it contains both $(SRCROOT)/../react-native/React and $(SRCROOT)/../../React - mark both as recursive.
6. Run your project (Cmd+R)

Usage

All you need is to require the react-native-camera module and then use the <Camera/> tag.

var React = require('react-native');
var {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  TouchableHighlight
} = React;
var Camera = require('react-native-camera');

var cameraApp = React.createClass({
  getInitialState() {
    return {
      cameraType: Camera.constants.Camera.back
    }
  },

  render() {

    return (
      <Camera
        ref="cam"
        style={styles.container}
        onBarCodeRead={this._onBarCodeRead}
        type={this.state.cameraType}
      >
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started, edit index.ios.js{'\n'}
          Press Cmd+R to reload
        </Text>
        <View>
          {preview}
        </View>
        <TouchableHighlight onPress={this._switchCamera}>
          <Text>The old switcheroo</Text>
        </TouchableHighlight>
        <TouchableHighlight onPress={this._takePicture}>
          <Text>Take Picture</Text>
        </TouchableHighlight>
      </Camera>
    );
  },
  _onBarCodeRead(e) {
    console.log(e);
  },
  _switchCamera() {
    var state = this.state;
    state.cameraType = state.cameraType === Camera.constants.Camera.back
      ? Camera.constants.Camera.front : Camera.constants.Camera.back;
    this.setState(state);
  },
  _takePicture() {
    var that = this;
    this.refs.cam.capture(function(err, data) {
      console.log(err, data);
    });
  }
});

AppRegistry.registerComponent('cameraApp', () => cameraApp);

Properties

aspect

Values: Camera.constants.Aspect.fit or "fit", Camera.constants.Aspect.fill or "fill" (default), Camera.constants.Aspect.stretch or "stretch"

The aspect property allows you to define how your viewfinder renders the camera's view. For instance, if you have a square viewfinder and you want to fill the it entirely, you have two options: "fill", where the aspect ratio of the camera's view is preserved by cropping the view or "stretch", where the aspect ratio is skewed in order to fit the entire image inside the viewfinder. The other option is "fit", which ensures the camera's entire view fits inside your viewfinder without altering the aspect ratio.

captureMode

Values: Camera.constants.CaptureMode.still (default)

The type of capture that will be performed by the camera - either a still image or (hopefully soon, video).

captureTarget

Values: Camera.constants.CaptureTarget.memory (default), Camera.constants.CaptureTarget.disk

This property allows you to specify the target output of the captured image data. By default the image binary is sent back as a base 64 encoded string. The disk output has been shown to improve capture response time, so that is the recommended value.

type

Values: Camera.constants.Camera.front or "front", Camera.constants.Camera.back or "back" (default)

Use the type property to specify which camera to use.

orientation

Values: Camera.constants.Orientation.landscapeLeft or "landscapeLeft", Camera.constants.Orientation.landscapeRight or "landscapeRight", Camera.constants.Orientation.portrait or "portrait" (default), Camera.constants.Orientation.portraitUpsideDown or "portraitUpsideDown"

The orientation property allows you to specify the current orientation of the phone to ensure the viewfinder is "the right way up."

TODO: Add support for an Auto value to automatically adjust for orientation changes.

onBarCodeRead

Will call the specified method when a barcode is detected in the camera's view.

Event contains data (the data in the barcode) and bounds (the rectangle which outlines the barcode.)

TODO: Only emit one event for each barcode scanned.

Component methods

You can access component methods by adding a ref (ie. ref="camera") prop to your <Camera> element, then you can use this.refs.camera.capture(cb), etc. inside your component.

capture([options,] callback)

Captures data from the camera. What is captured is based on the captureMode and captureTarget props. captureMode tells the camera whether you want a still image or -- in the future, this is not currently supported -- video. captureTarget allows you to specify how you want the data to be captured and sent back to you. The available targets are Camera.constants.CaptureTarget.memory and Camera.constants.CaptureTarget.disk - the latter has been shown to dramatically improve camera performance.

Subviews

This component supports subviews, so if you wish to use the camera view as a background or if you want to layout buttons/images/etc. inside the camera then you can do that.

Todo

These are some features I think would be important/beneficial to have included with this module. Pull requests welcome!

• Video support
• Flash mode setting
• Automatic orientation adjustment
• Tap to focus
• Optional facial recognition (w/ ability to style box around face)

---

Thanks to Brent Vatne (@brentvatne) for the react-native-video module which provided me with a great example of how to set up this module.