(Tcl) Square OAuth2 Access Token

Demonstrates how to get an access token for the Square API. This example is for desktop apps only (not web apps).

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load ./chilkat.dll

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

set oauth2 [new_CkOAuth2]

# This should be the port in the localhost callback URL for your app.  
# The callback URL would look like "http://localhost:3017/" if the port number is 3017.
CkOAuth2_put_ListenPort $oauth2 3017

# To use the production system, change the domains here to "connect.squareup.com"
CkOAuth2_put_AuthorizationEndpoint $oauth2 "https://connect.squareupsandbox.com/oauth2/authorize"
CkOAuth2_put_TokenEndpoint $oauth2 "https://connect.squareupsandbox.com/oauth2/token"

# Replace these with actual values.
CkOAuth2_put_ClientId $oauth2 "APPLICATION_ID"
CkOAuth2_put_ClientSecret $oauth2 "APPLICATION_SECRET"

# Make sure to include the scopes you'll need.
CkOAuth2_put_Scope $oauth2 "ITEMS_WRITE ITEMS_READ"

# Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
set url [CkOAuth2_startAuth $oauth2]
if {[CkOAuth2_get_LastMethodSuccess $oauth2] != 1} then {
    puts [CkOAuth2_lastErrorText $oauth2]
    delete_CkOAuth2 $oauth2
    exit
}

# Add the session=False query param to the URL.
set sbUrl [new_CkStringBuilder]

CkStringBuilder_Append $sbUrl $url
CkStringBuilder_Append $sbUrl "&session=False"
# Launch this URL in the browser.
set url [CkStringBuilder_getAsString $sbUrl]

# At this point, your application should load the URL in a browser.
# For example, 
# in C#: System.Diagnostics.Process.Start(url);
# in Java: Desktop.getDesktop().browse(new URI(url));
# in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
#              wsh.Run url
# in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
# in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
# The Microsoft account owner would interactively accept or deny the authorization request.

# Add the code to load the url in a web browser here...
# Add the code to load the url in a web browser here...
# Add the code to load the url in a web browser here...

# Now wait for the authorization.
# We'll wait for a max of 30 seconds.
set numMsWaited 0
while {expr [$numMsWaited < 30000]  &&  [[CkOAuth2_get_AuthFlowState $oauth2] < 3]} {
    CkOAuth2_SleepMs $oauth2 100
    set numMsWaited [expr $numMsWaited + 100]
}

# If there was no response from the browser within 30 seconds, then 
# the AuthFlowState will be equal to 1 or 2.
# 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
# 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
# In that case, cancel the background task started in the call to StartAuth.
if {[CkOAuth2_get_AuthFlowState $oauth2] < 3} then {
    CkOAuth2_Cancel $oauth2
    puts "No response from the browser!"
    delete_CkOAuth2 $oauth2
    delete_CkStringBuilder $sbUrl
    exit
}

# Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
# The possible AuthFlowState values are:
# 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
# 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
# 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if {[CkOAuth2_get_AuthFlowState $oauth2] == 5} then {
    puts "OAuth2 failed to complete."
    puts [CkOAuth2_failureInfo $oauth2]
    delete_CkOAuth2 $oauth2
    delete_CkStringBuilder $sbUrl
    exit
}

if {[CkOAuth2_get_AuthFlowState $oauth2] == 4} then {
    puts "OAuth2 authorization was denied."
    puts [CkOAuth2_accessTokenResponse $oauth2]
    delete_CkOAuth2 $oauth2
    delete_CkStringBuilder $sbUrl
    exit
}

if {[CkOAuth2_get_AuthFlowState $oauth2] != 3} then {
    puts "Unexpected AuthFlowState:[CkOAuth2_get_AuthFlowState $oauth2]"
    delete_CkOAuth2 $oauth2
    delete_CkStringBuilder $sbUrl
    exit
}

puts "OAuth2 authorization granted!"
puts "Access Token = [CkOAuth2_accessToken $oauth2]"

# Get the full JSON response:
set json [new_CkJsonObject]

CkJsonObject_Load $json [CkOAuth2_accessTokenResponse $oauth2]
CkJsonObject_put_EmitCompact $json 0

# The JSON response looks like this:

# {
#   "access_token": "EAAAE...depV",
#   "token_type": "bearer",
#   "expires_at": "2020-09-04T23:30:18Z",
#   "merchant_id": "MLQA83866KSR5",
#   "refresh_token": "EQAAEE...jeVfD6MV"
# }

puts [CkJsonObject_emit $json]

# Save the JSON to a file for future requests.
set fac [new_CkFileAccess]

CkFileAccess_WriteEntireTextFile $fac "qa_data/tokens/square.json" [CkJsonObject_emit $json] "utf-8" 0

delete_CkOAuth2 $oauth2
delete_CkStringBuilder $sbUrl
delete_CkJsonObject $json
delete_CkFileAccess $fac