(PureBasic) Get eBay Application Token

This example shows how to request an eBay Application token.

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkJsonObject.pb"
IncludeFile "CkDateTime.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkFileAccess.pb"
IncludeFile "CkHttpRequest.pb"
IncludeFile "CkHttpResponse.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ; See the Ebay documentation about Access token types
    ; Also see the Ebay documentation about client credentials grant flow

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

    ; If using the sandbox, the target endpoint will be:
    ; POST https://api.sandbox.ebay.com/identity/v1/oauth2/token

    ; If using the production (live) system, the target endpoint will be:
    ; POST https://api.ebay.com/identity/v1/oauth2/token

    ; The eBay client_id and client_secret needs to be sent
    ; in a Basic Authorization  request header, which has this format:
    ; Authorization: Basic <B64_encoded_oauth_credentials>

    ; Chilkat takes care of it.  You only need to set the Login = client_id,
    ; and password = client_secret, and indicate you want "Basic" HTTP Authorization.
    CkHttp::setCkLogin(http, "EBAY_CLIENT_ID")
    CkHttp::setCkPassword(http, "EBAY_CLIENT_SECRET")
    CkHttp::setCkBasicAuth(http, 1)

    ; Let's do the following POST:

    ;   HTTP method:   POST
    ;   URL (Sandbox): https://api.sandbox.ebay.com/identity/v1/oauth2/token
    ; 
    ;   HTTP headers:
    ;     Content-Type = application/x-www-form-urlencoded
    ;     Authorization = Basic <B64-encoded-oauth-credentials>
    ; 
    ;   Request body (wrapped for readability):
    ;     grant_type=client_credentials&
    ;     redirect_uri=<RuName-value>&
    ;     scope=<SPACE separated list of scopes>
    ; 

    ; Create an HttpRequest object to hold the request params.
    req.i = CkHttpRequest::ckCreate()
    If req.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpRequest::setCkHttpVerb(req, "POST")
    CkHttpRequest::ckAddParam(req,"grant_type","client_credentials")

    ; The scope query param indicates the access to be provided by the token.
    ; Multiple scopes can be specified by separating each with a SPACE char.
    ; See the Ebay OAuth scopes documentation

    CkHttpRequest::ckAddParam(req,"scope","https://api.ebay.com/oauth/api_scope")

    endPoint.s = "https://api.sandbox.ebay.com/identity/v1/oauth2/token"
    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,endPoint,req,resp)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkHttpResponse::ckDispose(resp)
        ProcedureReturn
    EndIf

    ; The response is JSON..
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoad(json,CkHttpResponse::ckBodyStr(resp))
    CkJsonObject::setCkEmitCompact(json, 0)

    ; If the response status code is not 200, then it failed.
    Debug "Response status code = " + Str(CkHttpResponse::ckStatusCode(resp))
    If CkHttpResponse::ckStatusCode(resp) <> 200
        Debug CkJsonObject::ckEmit(json)
        Debug "Failed."
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkHttpResponse::ckDispose(resp)
        CkJsonObject::ckDispose(json)
        ProcedureReturn
    EndIf

    ; We successfully retrieved an eBay access token.
    ; The actual access token string can be parsed from the JSON like this:
    accessToken.s = CkJsonObject::ckStringOf(json,"access_token")

    ; This application token is only valid for 7200 seconds (2 hours).  We'll want to refresh
    ; it before it expires.  (There is an online example for that..)
    ; For now, let's save the JSON to a file for our application to use.

    ; But before doing that, let's add to the JSON an expiration timestamp
    ; so we know when to refresh the token.
    dtExpire.i = CkDateTime::ckCreate()
    If dtExpire.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkDateTime::ckSetFromCurrentSystemTime(dtExpire)
    CkDateTime::ckAddSeconds(dtExpire,CkJsonObject::ckIntOf(json,"expires_in"))
    CkJsonObject::ckAppendString(json,"expire_time",CkDateTime::ckGetAsTimestamp(dtExpire,0))

    ; Persist the JSON to a file.
    fac.i = CkFileAccess::ckCreate()
    If fac.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkFileAccess::ckWriteEntireTextFile(fac,"qa_data/tokens/ebay.json",CkJsonObject::ckEmit(json),"utf-8",0)
    If success <> 1
        Debug CkFileAccess::ckLastErrorText(fac)
        Debug "Failed to save eBay Application token to file."
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        CkHttpResponse::ckDispose(resp)
        CkJsonObject::ckDispose(json)
        CkDateTime::ckDispose(dtExpire)
        CkFileAccess::ckDispose(fac)
        ProcedureReturn
    EndIf

    Debug CkJsonObject::ckEmit(json)
    Debug "Success."

    ; The output of this example is:

    ; 	{ 
    ; 	  "access_token": "v^1.1#i^1#p^1#I^3#r^0# ... Ajp1BQhJDgAA",
    ; 	  "token_type": "Application Access Token",
    ; 	  "expires_in": 7200,
    ; 	  "refresh_token": "N/A",
    ; 	  "expire_time": "2017-04-16T14:44:20Z"
    ; 	}
    ; 
    ; 	Success.
    ; 


    CkHttp::ckDispose(http)
    CkHttpRequest::ckDispose(req)
    CkHttpResponse::ckDispose(resp)
    CkJsonObject::ckDispose(json)
    CkDateTime::ckDispose(dtExpire)
    CkFileAccess::ckDispose(fac)


    ProcedureReturn
EndProcedure