Lua

Refresh a Dynamics CRM OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to refresh an expiring Dynamics CRM access token using the refresh token. endpoint.

(If a REST API call fails with a 401 unauthorized error, an application can auto-recover by refreshing the access token, and then re-send the request using the new token.)

Lua

local chilkat = require("chilkat")

-- This example requires the Chilkat API to have been previously unlocked.
-- See Global Unlock Sample for sample code.

-- We previously obtained an access token and saved the JSON to a file using this example:
-- Get Dynamics CRM OAuth2 Access Token

-- This example will examine the JSON and expiration date, and if near expiration will
-- refresh the access token.

local json = chilkat.JsonObject.new()
local success = json:load_file("qa_data/tokens/dynamicsCrm.json")
if not success then
    return
end

-- The contents of the JSON look like this:
-- {
--   "token_type": "Bearer",
--   "scope": "user_impersonation",
--   "expires_in": "3599",
--   "ext_expires_in": "0",
--   "expires_on": "1524783438",
--   "not_before": "1524779538",
--   "resource": "https://mydomain.api.crm.dynamics.com",
--   "access_token": "...",
--   "refresh_token": "...",
--   "id_token": "..."
-- }

-- The "expires_on" value is a Unix time.
local dtExpire = chilkat.DateTime.new()
dtExpire:set_from_unix_time(false, json:int_of("expires_on"))

-- If this date/time expires within 10 minutes of the current system time, refresh the token.

-- OK, we need to refresh the access token by sending a POST...
--

local req = chilkat.HttpRequest.new()
req:add_param("grant_type", "refresh_token")
req:add_param("redirect_uri", "http://localhost:3017/")
req:add_param("client_id", "DYNAMICS-CRM-CLIENT-ID")
req:add_param("client_secret", "DYNAMICS-CRM-SECRET-KEY")
req:add_param("refresh_token", json:string_of("refresh_token"))
req:add_param("resource", "https://mydynamicsdomain.api.crm.dynamics.com")

local http = chilkat.Http.new()

req.http_verb = "POST"
req.content_type = "application/x-www-form-urlencoded"

local resp = chilkat.HttpResponse.new()
success = http:http_req("https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token", req, resp)
if not success then
    print(http.last_error_text)
    return
end

-- Load the JSON response.
json:load(resp.body_str)
json.emit_compact = false

-- Show the JSON response.
print(json:emit())

print("Response status code: " .. resp.status_code)

-- If the response status code is not 200, then it's an error.
if resp.status_code ~= 200 then
    return
end

-- If an "expires_on" member does not exist, then add the JSON member by
-- getting the current system date/time and adding the "expires_in" seconds.
-- This way we'll know when the token expires.
if not json:has_member("expires_on") then
    dtExpire:set_from_current_system_time()
    dtExpire:add_seconds(json:int_of("expires_in"))
    json:append_string("expires_on", dtExpire:get_as_unix_time_str(false))
end

-- Save the refreshed access token JSON to a file for future requests.
local fac = chilkat.FileAccess.new()
fac:write_entire_text_file("qa_data/tokens/dynamicsCrm.json", json:emit(), "utf-8", false)