File Upload

Many applications need to upload the file to the backend. Hypi provides a simple API to do so!

Hypi’s core App has a type definition called File. A file can be uploaded using an endpoint. Once it is uploaded an object of File type gets created. The information about the file gets extracted and stored as a File object. The definition includes metadata about the file, the URL to download it, and more. You may place these file objects within your data model. For example, profile picture of a user with his personal information.

The file can be downloaded from the URL given in the object using an authorization token. Anonymous users cannot download the file. To allow access to other users, permission can be granted to download the file.

With this preliminary information, let’s get inside the File type definition.

type File {
    name: String!
    directory: String!
    path: String!
    isDirectory: Boolean!
    status: FileStatus
    url: URL
    type: String
    size: Long
    extension: String
    isStared: Boolean
    isSharable: Boolean
    content: String
    children(...): [File!]
}

Parameter	Type	Description
name	String	Name of the file
directory	String	The name of the directory
path	String	The path of the file
isDirectory	Boolean	If the file has to be uploaded in a virtual file system like Google Drive/Dropbox, this field is set to true
status	FileStatus	Status of file upload
url	URL	URL to download file
type	String	Media type
size	Long	Size of the file in Bytes
extension	String	Extension of the file (.txt,.jpg, etc)
isStared	Boolean	For the virtual file system, the file can be set to Starred status
isSharable	Boolean	File sharing status
content	String	For the virtual file system upload, the content of the file would be set to a String value. Otherwise, the content would be null.
children	File	For the virtual file system, the directory can have sub-files

Upload endpoint

To upload a file (any file can be uploaded, image, pdf, etc), use the following endpoint

POST /upload/**

Note the **, if you use a path like /upload/my/path, then the File object will have a directory value of /my/path. If you have many files to upload, you may put all of them in one directory.

Download endpoint

GET /file/<path>.ext

To download a file uploaded to the platform, the above URL pattern should be used.

The <path> is by default the ID of the File object. The .ext is the original extension of the file e.g. .txt. You may copy the value from path field of File object.

curl upload example

auth='<hypi-auth-token>'
curl -v https://api.hypi.app/upload/ -H "Accept: application/json" -H "Authorization: $auth" -H "hypi-domain: <instance-domain>" -F 0=@/path/to/file.txt

• The response of the upload is JSON
• The Authorization header is required
• The hypi-domain header is required (like other API requests)
• You may copy the authorization token and hypi instance domain from GraphQL configuration of the instance.
• @ is the root directory of the file to be uploaded.

In the following example of curl request, we are uploading logo.png file to Hypi domain. incineration.apps.hypi.app

curl -v https://api.hypi.app/upload/ -H "Accept: application/json" -H "Authorization: <auth-token>" -H "hypi-domain: incineration.apps.hypi.app" -F 0=@static/img/logo.png

The URL Path could be https://api.hypi.app/upload/mydir if you want to upload the file under mydir directory.

Here, we have uploaded an image file. So, an Image object also gets created that has details of the uploaded image. It contains the File object with file details.

type Image {
    name: String!
    file: File!
    description: String
    location: Geo
}

After executing curl command, let's retrieve the details of the file object.

GraphQL Query

{
  find(type: File, arcql: "*") {
    edges {
      node {
        ... on File {
          hypi {
            id
          }
          name
          directory
          path
          isDirectory
          status
          status
          url {
            path #Path to download file
          }
          type
          size
          extension
          isStared
          isSharable
          content
        }
      }
      cursor
    }
  }
}

Response

{
  "data": {
    "find": {
      "edges": [
        {
          "node": {
            "hypi": {
              "id": "01F35ZCSYBHTQ4JBWZ1KFXTDZR"
            },
            "name": "logo.png",
            "directory": "/",
            "path": "/logo.png",
            "isDirectory": false,
            "status": "UPLOADED",
            "url": {
              "path": "/file/01F322XSV13R9VAGJXW351PVBT-01F35ZCSYBHTQ4JBWZ1KFXTDZR.png"
            },
            "type": "image/png",
            "size": 13759,
            "extension": "png",
            "isStared": null,
            "isSharable": null,
            "content": null
          },
          "cursor": "01F35ZCSYBHTQ4JBWZ1KFXTDZR"
        }
      ]
    }
  }
}

curl download example

curl -v https://api.hypi.app/file/<id>.ext -H "Authorization: $auth"

Let's download the file that we uploaded earllier.

curl -v https://api.hypi.app/file/01F322XSV13R9VAGJXW351PVBT-01F35ZCSYBHTQ4JBWZ1KFXTDZR.png -H "Authorization: <auth-token>" --output filedownload.png  

--ouput filedownload.png would redirect the data from the file to an output file.

note

You need to create the URL to download a file. Copy the path from File object and append it to the hypi endpoint.

In the above example, we provide an authorisation token. This is because file resource is private to the account which created it by default. To give access to other users or allow anonymous download, an access grant must be created for the File resource.

To give the anonymous users access (no token required), create an AccessRight as follows.

mutation {
  upsert(
    values: {
      AccessRight: [
        {
          resource: "01F35ZCSYBHTQ4JBWZ1KFXTDZR"
          resourceType: "File"
          operationType: "Query"
          operation: "*"
          permissionType: RBP
          approved: true
          members: { hypi: { id: "anonymous" } }
        }
      ]
    }
  ) {
    id
  }
}

Note: resource field has the hypi.id of the file uploaded. To grant access to specific users, provide hypi.id s of the user Accounts in the members field.

In this example, we explicitly give anonymous users access to the file uploaded.

IMPORTANT

You need to enable Anonymous requests in the API configurations for downloading files without authorization headers.

Due to the permission above, the curl request can now be made without any authorisation headers.

curl -v https://api.hypi.app/file/<id>.ext

Now you can download the file without the hassle of providing authorization token.

curl -v https://api.hypi.app/file/01F322XSV13R9VAGJXW351PVBT-01F35ZCSYBHTQ4JBWZ1KFXTDZR.png --output file.png

Read More...

• How to upload files to Hypi’s low code backend
• How to download stored files
• Profile Image upload using Hypi
• Using OpenWhisk Web action and Hypi’s File Upload APIs, manage QR code images
• How to give access to anonymous users to download files