Swift

Dropbox: OAuth2 Authorization to Obtain an Access Token

See more Dropbox Examples

Demonstrates how to get a Dropbox OAuth2 access token from a desktop application or script.

This example runs the OAuth 2.0 authorization flow that lets the user sign in to Dropbox and authorize your app.

Swift

func chilkatTest() {
    var success: Bool = false

    // For more information about the OAuth2, see OAuth 2.0 Authorization Flow

    let oauth2 = CkoOAuth2()!

    // The port should match the Authorized Redirect URL in your Dropbox app, 
    // which would look like "http://localhost:3017/"
    oauth2.listenPort = 3017

    // IMPORTANT: One of the OAuth2 redirect URIs for your Dropbox app must be
    // exactly this string:  http://localhost:3017/

    oauth2.authorizationEndpoint = "https://www.dropbox.com/oauth2/authorize"
    oauth2.tokenEndpoint = "https://api.dropboxapi.com/oauth2/token"

    // Replace this with your actual Dropbox App Key
    oauth2.clientId = "DROPBOX_APP_KEY"

    // This is for Require Proof Key for Code Exchange (PKCE)
    // See OAuth2 PKCE Explained
    oauth2.codeChallenge = true
    oauth2.codeChallengeMethod = "S256"

    // Add token_access_type=offline to also get a refresh token in the response
    oauth2.addAuthQueryParam(name: "token_access_type", value: "offline")

    // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    var url: String? = oauth2.startAuth()
    if oauth2.lastMethodSuccess != true {
        print("\(oauth2.lastErrorText!)")
        return
    }

    print("url = \(url!)")

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    success = oauth2.launchBrowser(url: url)
    if success == false {
        print("\(oauth2.lastErrorText!)")
        return
    }

    // Wait for the user to approve or deny authorization in the browser.
    var numMsWaited: Int = 0
    while (numMsWaited < 90000) && (oauth2.authFlowState.intValue < 3) {
        oauth2.sleepMs(millisec: 100)
        numMsWaited = numMsWaited + 100
    }

    // If the browser does not respond within the specified time, AuthFlowState will be:
    // 
    // 1: Waiting for Redirect - The OAuth2 background thread is waiting for the browser's redirect request.
    // 2: Waiting for Final Response - The thread is awaiting the final access token response.
    // In either case, cancel the background task initiated by StartAuth.

    if oauth2.authFlowState.intValue < 3 {
        oauth2.cancel()
        print("No response from the browser!")
        return
    }

    // Check AuthFlowState to determine if authorization was granted, denied, or failed:
    // 
    // 3: Success - OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
    // 4: Access Denied - OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
    // 5: Failure - OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

    if oauth2.authFlowState.intValue == 5 {
        print("OAuth2 failed to complete.")
        print("\(oauth2.failureInfo!)")
        return
    }

    if oauth2.authFlowState.intValue == 4 {
        print("OAuth2 authorization was denied.")
        print("\(oauth2.accessTokenResponse!)")
        return
    }

    if oauth2.authFlowState.intValue != 3 {
        print("Unexpected AuthFlowState:\(oauth2.authFlowState.intValue)")
        return
    }

    print("OAuth2 authorization granted!")

    let json = CkoJsonObject()!
    json.load(json: oauth2.accessTokenResponse)
    json.emitCompact = false

    print("Access Token Response = \(json.emit()!)")

    // A sample access token response:

    // {
    //   "access_token": "...",
    //   "token_type": "bearer",
    //   "expires_in": 14399,
    //   "refresh_token": "...",
    //   "scope": "account_info.read",
    //   "uid": "562542581",
    //   "account_id": "dbid:AACQhDS0E3_Vb72Ynd0F-GxGWdTI2qcTHzA"
    // }

    print("Access Token = \(oauth2.accessToken!)")

    // Save the JSON access token response to a file for subsequent use..
    json.writeFile(path: "qa_data/tokens/dropbox.json")

}