Lua Requires Chilkat v10.1.2+

Facebook OAuth2 Access Token

See more Facebook Examples

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

local chilkat = require("chilkat")

-- To further clarify, see OAuth 2.0 Authorization Flow

local oauth2 = chilkat.OAuth2.new()

-- This should match the Site URL configured for your Facebook APP, such as "http://localhost:3017/"
oauth2.listen_port = 3017

oauth2.authorization_endpoint = "https://www.facebook.com/dialog/oauth"
oauth2.token_endpoint = "https://graph.facebook.com/oauth/access_token"

-- Replace this with your actual App ID
oauth2.client_id = "APP_ID"

-- Set the Scope to a comma-separated list of permissions the app wishes to request.
-- See https://developers.facebook.com/docs/facebook-login/permissions/ for a full list of permissions.
oauth2.scope = "public_profile,user_friends,email,user_posts,user_likes,user_photos"

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

-- 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!")
print("Access Token = " .. oauth2.access_token)