(PowerBuilder) Egyptian eReceipt OAuth2 Client Credentials

See more Egypt eReceipt Examples

Get an OAuth2 access token for the Egyptian eReceipt REST API using client credentials (no interactivity with a web browser required).

For more information, see https://sdk.invoicing.eta.gov.eg/ereceiptapi/01-authenticate-pos/

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Http
integer li_Success
oleobject loo_Req
oleobject loo_Resp
oleobject loo_SbResponseBody
oleobject loo_JResp
integer li_RespStatusCode
string ls_Token_type
string ls_Access_token
string ls_Expires_in
string ls_Scope

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

loo_Http = create oleobject
// Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
li_rc = loo_Http.ConnectToNewObject("Chilkat.Http")
if li_rc < 0 then
    destroy loo_Http
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// Note: Any provider of a REST API, such as the Egyptian government in this case, can make life 
// much easier for developers by providing one or more of the following in the API documentation:
// 
// 1) A sample CURL statement for each API call.
// 2) A Postman collection, or Swagger/OpenAPI specification file.
// 3) A sample of a raw HTTP request and response for each API call.
// 
// The sample CURL statements or raw HTTP request/responses do not need to comprehensively show all 
// possible options.  Providing a sample allows one to quickly make a successful API call.
// It also allows for code generation directly from the CURL, Postman collection, or raw request/response,
// and it tends to answer all questions about the format/structure of a request that, suprisingly,
// remain ambiguous or not obvious in other forms of documentation.

loo_Req = create oleobject
// Use "Chilkat_9_5_0.HttpRequest" for versions of Chilkat < 10.0.0
li_rc = loo_Req.ConnectToNewObject("Chilkat.HttpRequest")

loo_Req.AddParam("grant_type","client_credentials")
// Use your actual client ID and client secret...
loo_Req.AddParam("client_id","d0394a9f-0607-40de-a978-2d3eb8375b04")
loo_Req.AddParam("client_secret","6d62315e-d65a-4e41-9112-4195ea834edf")

loo_Req.AddHeader("posserial","1234567899")
loo_Req.AddHeader("pososversion","os")
loo_Req.AddHeader("posmodelframework","1")
loo_Req.AddHeader("presharedkey","03ac674216f3e1...")

// When writing this example, the documentation at https://sdk.invoicing.eta.gov.eg/ereceiptapi/01-authenticate-pos/
// shows us the HTTP verb and path (POST /connect/token), however,
// we don't see the actual domain where the request is to be sent.
// What are the endpoints???
// It took some searching, but we found some endpoints here:  https://sdk.invoicing.eta.gov.eg/faq/
// It's not immediately apparent which endpoint is to be used with a given API call.
// Why not just include the endpoint in the documentation for each REST API call?
// Endpoints are literally the #1 thing that needs to be known.
// They can't just be buried in a FAQ.  They should be up-front and obvious.
// 
// So.. we're guessing the endpoint is likely "https://invoicing.eta.gov.eg/connect/token"
loo_Resp = loo_Http.PostUrlEncoded("https://invoicing.eta.gov.eg/connect/token",loo_Req)
if loo_Http.LastMethodSuccess = 0 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Http
    destroy loo_Req
    return
end if

loo_SbResponseBody = create oleobject
// Use "Chilkat_9_5_0.StringBuilder" for versions of Chilkat < 10.0.0
li_rc = loo_SbResponseBody.ConnectToNewObject("Chilkat.StringBuilder")

loo_Resp.GetBodySb(loo_SbResponseBody)

loo_JResp = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_JResp.ConnectToNewObject("Chilkat.JsonObject")

loo_JResp.LoadSb(loo_SbResponseBody)
loo_JResp.EmitCompact = 0

Write-Debug "Response Body:"
Write-Debug loo_JResp.Emit()

li_RespStatusCode = loo_Resp.StatusCode
Write-Debug "Response Status Code = " + string(li_RespStatusCode)
if li_RespStatusCode >= 400 then
    Write-Debug "Response Header:"
    Write-Debug loo_Resp.Header
    Write-Debug "Failed."
    destroy loo_Resp
    destroy loo_Http
    destroy loo_Req
    destroy loo_SbResponseBody
    destroy loo_JResp
    return
end if

destroy loo_Resp

// If successful, the OAuth2 access token JSON looks like this:

// {
//   "token_type": "Bearer",
//   "access_token": "eyJraW......R2sbqrY",
//   "expires_in": "3600",
//   "scope": "..."
// }

ls_Token_type = loo_JResp.StringOf("token_type")
ls_Access_token = loo_JResp.StringOf("access_token")
ls_Expires_in = loo_JResp.StringOf("expires_in")
ls_Scope = loo_JResp.StringOf("scope")


destroy loo_Http
destroy loo_Req
destroy loo_SbResponseBody
destroy loo_JResp