CODEWITHSUNDEEP
react-nativeexpo
sina farbod
sina farbod

Reputation: 497

How to get file extension with expo FileSystem?

I'm using expo FileSystem to get photos and videos from cameraRoll. is there any way to get these files extensions?

Upvotes: 3

Views: 7499

Answers (1)

Andrew
Andrew

Reputation: 28539

Using ImagePicker

If you have asked for permission and are able to get a response from the ImagePicker you should get an object that looks like this.

{
  "cancelled": false,
  "height": 2436,
  "type": "image",
  "uri": "file:///lots/of/directories/where/the/image/is/stored/ImagePicker/B69EA641-4738-4425-8319-FE190FC4BD6D.png",
  "width": 1125,
}

If you call the ImagePicker like this (remember this is an await so it should be wrapped in a try/catch)

let result = await ImagePicker.launchImageLibraryAsync({mediaTypes:'Images'});

You can then access the uri by using result.uri

So we can do something like this

let uri = result.uri;
let fileExtension = uri.substr(uri.lastIndexOf('.') + 1);

Remember the user can cancel the request so you should check the result.cancelled is false before trying to get the file extension, otherwise you will have issues as the uri will not exist.

Using CameraRoll

The responses from using the Camera Roll aren't consistent across platforms. The following code will access the first video on the device.

let params = { first: 1, assetType: CameraRoll.AssetTypeOptions.Videos }; 
let result = await CameraRoll.getPhotos(params)
let videos = result.edges // the edges key stores an array of objects

Android

{
  node: {
    group_name: 0,
    image:  {
      height: 1280,
      playableDuration: 56,
      uri: "content://media/external/video/media/125",
      width: 720,
    },
    timestamp: 1541516873,
    type: "video/mp4",
  },
}

iOS

{
  node:  {
    group_name: "Camera Roll",
    image:  {
      filename: "IMG_5030.MOV",
      height: 1080,
      isStored: true,
      playableDuration: 612,
      uri: "assets-library://asset/asset.MOV?id=10711D3D-EBDC-4EF2-A849-411D593A0B15&ext=MOV",
      width: 1920,
    },
    location:  {
      altitude: 0,
      heading: -1,
      latitude: 0.0,
      longitude: 0.0,
      speed: -1,
    },
    timestamp: 1544786625,
    type: "ALAssetTypeVideo",
  },
}

As you can see Android doesn't give a specific filename, unlike iOS which does. For iOS you can extract the file extension using the method I described above. Unfortunately for Android the only way to get the actual file extension is to use the ImagePicker.

Upvotes: 5

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