(Tcl) PayPal -- Get an OAuth 2.0 Access Token

Demonstrates how to send a request to get a PayPal OAuth2 access token. Sends an HTTP request equivalent to the following:

curl https://api.sandbox.paypal.com/v1/oauth2/token \
  -H "Accept: application/json" \
  -H "Accept-Language: en_US" \
  -u "Client-Id:Secret" \
  -d "grant_type=client_credentials"

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

# Note: Requires Chilkat v9.5.0.64 or greater.

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

set rest [new_CkRest]

# Make the initial connection.
# A single REST object, once connected, can be used for many PayPal REST API calls.
# The auto-reconnect indicates that if the already-established HTTPS connection is closed,
# then it will be automatically re-established as needed.
set bAutoReconnect 1
set success [CkRest_Connect $rest "api.sandbox.paypal.com" 443 1 $bAutoReconnect]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

# Duplicate this request:

# 	curl https://api.sandbox.paypal.com/v1/oauth2/token \
# 	  -H "Accept: application/json" \
# 	  -H "Accept-Language: en_US" \
# 	  -u "Client-Id:Secret" \
# 	  -d "grant_type=client_credentials"

CkRest_AddHeader $rest "Accept" "application/json"
CkRest_AddHeader $rest "Accept-Language" "en_US"

# For additional help on where to find  your client ID and API secret, see PayPal Client_ID and API_Secret
CkRest_SetAuthBasic $rest "PAYPAL_REST_API_CLIENT_ID" "PAYPAL_REST_API_SECRET"

CkRest_AddQueryParam $rest "grant_type" "client_credentials"

set responseStr [CkRest_fullRequestFormUrlEncoded $rest "POST" "/v1/oauth2/token"]
if {[CkRest_get_LastMethodSuccess $rest] != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkRest $rest
    exit
}

puts [CkRest_lastRequestHeader $rest]

# A sample response:

# 	{
# 	  "scope": "https://api.paypal.com/v1/payments/.* https://api.paypal.com/v1/vault/credit-card https://api.paypal.com/v1/vault/credit-card/.*",
# 	  "access_token": "EEwJ6tF9x5WCIZDYzyZGaz6Khbw7raYRIBV_WxVvgmsG",
# 	  "token_type": "Bearer",
# 	  "app_id": "APP-6XR95014BA15863X",
# 	  "expires_in": 28800
# 	}

set json [new_CkJsonObject]

CkJsonObject_Load $json $responseStr
CkJsonObject_put_EmitCompact $json 0

# Check the response status code.  A 200 indicates success..
if {[CkRest_get_ResponseStatusCode $rest] != 200} then {
    puts [CkJsonObject_emit $json]
    puts "Failed."
    delete_CkRest $rest
    delete_CkJsonObject $json
    exit
}

# Given that the access token expires in approx 8 hours,
# let's record the date/time this token was created.
# This will allow us to know beforehand if the token
# is expired (and we can then fetch a new token).
set dateTime [new_CkDateTime]

set bLocalTime 0
set dtNow [CkDateTime_GetAsUnixTime $dateTime $bLocalTime]
CkJsonObject_AppendInt $json "tokenCreateTimeUtc" $dtNow

# Examine the access token and save to a file.
puts "Access Token: [CkJsonObject_stringOf $json access_token]"
puts "Full JSON Response:"
puts [CkJsonObject_emit $json]

set sbResponse [new_CkStringBuilder]

CkStringBuilder_Append $sbResponse [CkJsonObject_emit $json]
set bEmitBom 0
CkStringBuilder_WriteFile $sbResponse "qa_data/tokens/paypal.json" "utf-8" $bEmitBom

delete_CkRest $rest
delete_CkJsonObject $json
delete_CkDateTime $dateTime
delete_CkStringBuilder $sbResponse