Lua Requires Chilkat v10.1.2+

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.

Lua

local chilkat = require("chilkat")

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

local oauth2 = chilkat.OAuth2.new()

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

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

oauth2.authorization_endpoint = "https://www.dropbox.com/oauth2/authorize"
oauth2.token_endpoint = "https://api.dropboxapi.com/oauth2/token"

-- Replace this with your actual Dropbox App Key
oauth2.client_id = "DROPBOX_APP_KEY"

-- This is for Require Proof Key for Code Exchange (PKCE)
-- See OAuth2 PKCE Explained
oauth2.code_challenge = true
oauth2.code_challenge_method = "S256"

-- Add token_access_type=offline to also get a refresh token in the response
oauth2:add_auth_query_param("token_access_type", "offline")

-- Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
local url = oauth2:start_auth()
if not oauth2.last_method_success then
    print(oauth2.last_error_text)
    return
end

print("url = " .. url)

-- Launch the default browser on the system and navigate to the url.
local success = oauth2:launch_browser(url)
if not success then
    print(oauth2.last_error_text)
    return
end

-- Wait for the user to approve or deny authorization in the browser.
local numMsWaited = 0
while (numMsWaited < 90000) and (oauth2.auth_flow_state < 3) do
    oauth2:sleep_ms(100)
    numMsWaited = numMsWaited + 100
end

-- 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.auth_flow_state < 3 then
    oauth2:cancel()
    print("No response from the browser!")
    return
end

-- 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.auth_flow_state == 5 then
    print("OAuth2 failed to complete.")
    print(oauth2.failure_info)
    return
end

if oauth2.auth_flow_state == 4 then
    print("OAuth2 authorization was denied.")
    print(oauth2.access_token_response)
    return
end

if oauth2.auth_flow_state ~= 3 then
    print("Unexpected AuthFlowState:" .. oauth2.auth_flow_state)
    return
end

print("OAuth2 authorization granted!")

local json = chilkat.JsonObject.new()
json:load(oauth2.access_token_response)
json.emit_compact = 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.access_token)

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