(PureBasic) Get eBay Application Token

This example shows how to request an eBay Application token.

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()

    ; 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")

    ; (The PostUrlEncoded method automatically sets the Content-Type header equal to "application/x-www-form-urlencoded")
    endPoint.s = "https://api.sandbox.ebay.com/identity/v1/oauth2/token"
    resp.i = CkHttp::ckPostUrlEncoded(http,endPoint,req)
    If CkHttp::ckLastMethodSuccess(http) <> 1
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        CkHttpRequest::ckDispose(req)
        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)
        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.i = 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)
        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)
    CkJsonObject::ckDispose(json)
    CkDateTime::ckDispose(dtExpire)
    CkFileAccess::ckDispose(fac)


    ProcedureReturn
EndProcedure