PureBasic

USPS OAuth2 Client Credentials

See more OAuth2 Examples

Get an OAuth2 access token for the United States Postal Service (USPS) REST API. PureBasic

IncludeFile "CkHttpResponse.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkStringBuilder.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkHttpRequest.pb"

Procedure ChilkatExample()

    success.i = 0

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

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Implements the following CURL command:

    ; curl -X POST https://apis.usps.com/oauth2/v3/token \
    ;   -H "Content-Type: application/x-www-form-urlencoded" \
    ;   -d "grant_type=client_credentials" \
    ;   -d "client_id=123456789" \
    ;   -d "client_secret=A1B2C3D4E5" \
    ;   -d "scope=ResourceA+ResourceB+ResourceC"

    ; Use the following online tool to generate HTTP code from a CURL command
    ; Convert a cURL Command to HTTP Source Code

    req.i = CkHttpRequest::ckCreate()
    If req.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpRequest::ckAddParam(req,"grant_type","client_credentials")
    CkHttpRequest::ckAddParam(req,"client_id","123456789")
    CkHttpRequest::ckAddParam(req,"client_secret","A1B2C3D4E5")
    CkHttpRequest::ckAddParam(req,"scope","ResourceA+ResourceB+ResourceC")

    CkHttpRequest::setCkHttpVerb(req, "POST")
    CkHttpRequest::setCkContentType(req, "application/x-www-form-urlencoded")

    resp.i = CkHttpResponse::ckCreate()
    If resp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkHttp::ckHttpReq(http,"https://apis.usps.com/oauth2/v3/token",req,resp)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkHttpResponse::ckDispose(resp)
        ProcedureReturn
    EndIf

    sbResponseBody.i = CkStringBuilder::ckCreate()
    If sbResponseBody.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpResponse::ckGetBodySb(resp,sbResponseBody)

    jResp.i = CkJsonObject::ckCreate()
    If jResp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoadSb(jResp,sbResponseBody)
    CkJsonObject::setCkEmitCompact(jResp, 0)

    Debug "Response Body:"
    Debug CkJsonObject::ckEmit(jResp)

    respStatusCode.i = CkHttpResponse::ckStatusCode(resp)
    Debug "Response Status Code = " + Str(respStatusCode)
    If respStatusCode >= 400
        Debug "Response Header:"
        Debug CkHttpResponse::ckHeader(resp)
        Debug "Failed."
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkHttpResponse::ckDispose(resp)
        CkStringBuilder::ckDispose(sbResponseBody)
        CkJsonObject::ckDispose(jResp)
        ProcedureReturn
    EndIf

    ; Sample JSON response:
    ; (Sample code for parsing the JSON response is shown below)

    ; {
    ;   "access_token": "eyJraWQiOiIxMDEwMTAiLCJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiJ9.eyJzdWIiOiIiLCJhdWQiOiJhZGRyZXNzZXMgaW50ZXJuYXRpb25hbC1wcmljZXMgc3Vic2NyaXB0aW9ucyBwYXltZW50cyBwaWNrdXAgdHJhY2tpbmcgbGFiZWxzIHNjYW4tZm9ybXMgY29tcGFuaWVzIHNlcnZpY2UtZGVsaXZlcnktc3RhbmRhcmRzIGxvY2F0aW9ucyBpbnRlcm5hdGlvbmFsLWxhYmVscyBwcmljZXMiLCJhenAiOiJoeXI3YjN2Q1J0cFl0QUhNMWE4Y2RVcmt5eUZtTmtiZyIsIm9yZ2FuaXphdGlvbl9pZCI6IjAiLCJpc3MiOiJ1cm46XC9cL2FwaS51c3BzLmNvbSIsImV4cCI6MTY4MDkxNzc4NiwiaWF0IjoxNjgwODg4OTg2LCJqdGkiOiI3YjU5MzJlMS05NjIxLTQzZDAtYTMyNy0xMzIxYWVjNzJjZGYifQ.QzrUxlT2rG4jvYbMDGnk23j8ZYfHJcdXPKR9CbSmcKeVpURaHhEMpPB6K4x5ut3xxeEGSzeE5VRz8vixI4iqyHsD8rSdkLTPHy0iovUHOZQBAJVQ6hii9jpLhxUXmiTtH3jKzSj_f2fuNmZbIGhf-CR2FBeWF-aBPzEDEMV95nkCUMfW_Z2BmkbraSfvQZxkCO-cLrMAwlYcrzUtaJ7vnazeQB4sep5BBHBEvsa4kfq6_tz6BAKgv3R7cI2NkSv-wgy_IGoTjVCMTS8mJHGs_t8cWCO8-z4lxW1tUwIBKOCUDpmEEnGgiG6Sl0C_gGl4bZ5cDSl4IgPpcOVi9jZ7LA",
    ;   "token_type": "Bearer",
    ;   "issued_at": 1680888985929,
    ;   "expires_in": 28799,
    ;   "status": "approved",
    ;   "scope": "addresses international-prices subscriptions payments pickup tracking labels scan-forms companies service-delivery-standards locations international-labels prices",
    ;   "issuer": "api.usps.com",
    ;   "client_id": "hyr7b3vCRtpYtAHM1a8cdUrkyyFmNkbg",
    ;   "application_name": "Silver Shipper Developer",
    ;   "api_products": "[Shipping-Silver]",
    ;   "public_key": "LS0tLS1CRUdJTiBQVUJMSUMgS0VZLS0tLS0KTUlJQklqQU5CZ2txaGtpRzl3MEJBUUVGQUFPQ0FROEFNSUlCQ2dLQ0FRRUF4QWxwZjNSNEE1S0lwZnhJVWk1bgpMTFByZjZVZTV3MktzeGxSVzE1UWV0UzBjWGVxaW9OT2hXbDNaaVhEWEdKT3ZuK3RoY0NWVVQ3WC9JZWYvTENZCkhUWk1kYUJOdW55VHEwT2RNZmVkUU8zYUNKZmwvUnJPTHYyaG9TRDR4U1YxRzFuTTc1RTlRYitFZ1p0cmFEUXoKNW42SXRpMUMzOHFGMjU5NVRHUWVUemx3Wk1LQng1VTY2bGwzNzlkZ2plTUJxS3ppVHZHWEpOdVg5ZzRrRlBIaApTLzNERm9FNkVFSW8zUHExeDlXTnRaSm93VkRwQUVZZTQ3SU1UdXJDN2NGcXp2d3M1b1BDRHQ4c083N2lUdDN0Cm1vK3NrM2ExWnZSaGs2WUQ3Zkt1UldQVzFEYUM4dC9pazlnWnhqQndYNlZsSUhDRzRZSHlYejZteWdGV09jMmEKOVFJREFRQUIKLS0tLS1FTkQgUFVCTElDIEtFWS0tLS0t"
    ; }

    ; Sample code for parsing the JSON response...
    ; Use the following online tool to generate parsing code from sample JSON:
    ; Generate Parsing Code from JSON

    access_token.s = CkJsonObject::ckStringOf(jResp,"access_token")
    token_type.s = CkJsonObject::ckStringOf(jResp,"token_type")
    issued_at.i = CkJsonObject::ckIntOf(jResp,"issued_at")
    expires_in.i = CkJsonObject::ckIntOf(jResp,"expires_in")
    status.s = CkJsonObject::ckStringOf(jResp,"status")
    scope.s = CkJsonObject::ckStringOf(jResp,"scope")
    issuer.s = CkJsonObject::ckStringOf(jResp,"issuer")
    client_id.s = CkJsonObject::ckStringOf(jResp,"client_id")
    application_name.s = CkJsonObject::ckStringOf(jResp,"application_name")
    api_products.s = CkJsonObject::ckStringOf(jResp,"api_products")
    public_key.s = CkJsonObject::ckStringOf(jResp,"public_key")


    CkHttp::ckDispose(http)
    CkHttpRequest::ckDispose(req)
    CkHttpResponse::ckDispose(resp)
    CkStringBuilder::ckDispose(sbResponseBody)
    CkJsonObject::ckDispose(jResp)


    ProcedureReturn
EndProcedure