Processing REST and SOAP Request
Processing REST Request
The REST request processing has 3 steps:
1. Passing parameter keys and values in a URL
2. Making a call to ECS
3. Obtaining the response in XML format
SFXHTTPConnection class is used for REST connection. In the source code below, _http is an instance of SFXHTTPConnection class.
SFCError SGRNetworkDialogSet::Connect(Void)
{
SFCError error;
// access by REST
if ((error = _http.Open()) == SFERR_NO_ERROR)
{
if ((error = _http.SetMethod("GET")) == SFERR_NO_ERROR)
// Make a call to ECS and get the response by callback function
error = _http.Connect(_url, CALLBACK_FUNCTION(ConnectCallback));
}
//notify if error occured
if (error != SFERR_NO_ERROR)
{
_spp(NOTIFY_CONNECT_START, error, _reference);
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
_errorDialog.Open(HTTP_ERROR_TITLE,
HTTP_ERROR_CODE1,
DIALOG_OK,
this);
}
return error;
}
Below is the implementation of the ConnectCallback function.
CALLBACK_IMPLEMENT_SFXHTTPCONNECTION(SGRNetworkDialogSet, ConnectCallback, error)
{
TRACE("CALLBACK_IMPLEMENT_SFXHTTPCONNECTION");
if (error == SFERR_NO_ERROR) {
// Get the stream reader
error = _http.GetStreamReader(1024, &_reader);
if (error == SFERR_NO_ERROR)
// then get data using callback function
error = _reader.Fetch(CALLBACK_FUNCTION(FetchCallback));
}
// notify if error occurred
if (error != SFERR_NO_ERROR) {
_spp(NOTIFY_ERROR, error, _reference);
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
_errorDialog.Open(HTTP_ERROR_TITLE,
HTTP_ERROR_CODE2,
DIALOG_OK,
this);
}
return;
}
Below is the implementation of the FetchCallback function.
CALLBACK_IMPLEMENT_SFXBINARYSTREAMREADER(SGRNetworkDialogSet, FetchCallback, error)
{
TRACE("CALLBACK_IMPLEMENT_SFXBINARYSTREAMREADER");
SFXBuffer _tempBuffer;
if (error == SFERR_NO_ERROR) {
// get a chunk of data
_tempBuffer.SetSize(_reader.GetReadableSize());
_reader.Read(&_tempBuffer);
// _string holds the returned text in XML format
error = _receivedBuffer.Add(_tempBuffer);
if (_reader.Ends() && _reader.GetReadableSize() == 0) {
// if no data remains
// close the connection
_http.Close();
// close the dialog
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
// notify the application
_connecting = false;
//DBGPRINTF("Network connect end...");
_spp(NOTIFY_CONNECT_END, error, _reference);
}
else { // if there is remaining data, fetch again
_reader.Fetch(CALLBACK_FUNCTION(FetchCallback));
}
}
else {
_http.Close();
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
_spp(NOTIFY_ERROR, error, _reference);
_errorDialog.Open(HTTP_ERROR_TITLE,
HTTP_ERROR_CODE3,
DIALOG_OK,
this);
}
return;
}
Processing SOAP Request
The SFXSOAPRPC class is used for SOAP request. This class accesses to the ECS by making a remote procedure call.
The return data in XML format is then parsed by the SFXSOAPParser class.
Developers can access to the elements such as the header, the body, the fault of the parsed XML document tree through the instance of the SFXSOAPParser class.
The source code below shows how to use SFXSOAPRPC class to set parameters and get the body element of the XML document.
SFCError SGRSOAPDialogSet::SOAPConnect(Void)
{
SFCError error (SFERR_NO_ERROR);
// set method name
_rpc.SetMethodName(_params->operation);
// set SOAP EncodingStyle
_rpc.SetEncodingStyle("http://schemas.xmlsoap.org/soap/encoding/");
// set target object URI
_rpc.SetTargetObjectURI(TARGET_URI);
// set AWSAccessKeyId
error = _rpc.AddParameter("AWSAccessKeyId",
SFXBuffer(SFXAnsiString(AMAZON_ID)));
if (error != SFERR_NO_ERROR) return error;
//
// set method parameters
//
// set request parameter
error = _rpc.AddParameter("Request",
SFXBuffer::EmptyInstance(),
SFXSOAPRPC::PARAMETER::UNKNOWN);
if (error != SFERR_NO_ERROR) return error;
// set SearchIndex parameter
if (_params->_set_search_index)
{
error = _rpc.AddParameter("SearchIndex",
SFXBuffer(_params->search_index));
if (error != SFERR_NO_ERROR) return error;
}
// set BrowseNode parameter
if (_params->_set_browse_node)
{
error = _rpc.AddParameter("BrowseNode",
SFXBuffer(_params->browse_node));
if (error != SFERR_NO_ERROR) return error;
}
// set ResponseGroup parameter
error = _rpc.AddParameter("ResponseGroup",
SFXBuffer(_params->response_group));
if (error != SFERR_NO_ERROR) return error;
// set Keywords parameter
if(_params->_set_keyword){
error = _rpc.AddParameter("Keywords",
SFXBuffer(_params->keyword));
if (error != SFERR_NO_ERROR) return error;
}
// set ItemId parameter
if(_params->_set_asin)
{
error = _rpc.AddParameter("ItemId",
SFXBuffer( _params->asin));
if (error != SFERR_NO_ERROR) return error;
}
// make a remote procedure call
// and get the body elemnet by SOAP_Notify function
error = _rpc.Invoke(END_POINT_URL,
SOAP_ACTION_URI,
SOAP_Notify, this);
return error;
}
Below is the implementation of the SOAP_Notify function.
Void SGRSOAPDialogSet::SOAP_Notify(SFCError error,
const SFXSOAPRPC::Params& result,
const SFXSOAPRPC::FAULT& fault,
SFXSOAPParserConstRef soap,
VoidPtr reference)
{
static_cast<SGRSOAPDialogSetPtr>(reference)->On_SOAP_Notify(error, result, fault, soap);
}
Void SGRSOAPDialogSet::On_SOAP_Notify(SFCError error,
const SFXSOAPRPC::Params& result,
const SFXSOAPRPC::FAULT& fault,
SFXSOAPParserConstRef soap )
{
// if error occured
if (error != SFERR_NO_ERROR)
{
_spp(NOTIFY_CONNECT_START, error, _reference);
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
_errorDialog.Open(SOAP_ERROR_TITLE, SOAP_ERROR_CODE, DIALOG_OK, this);
}
else// if success
{
_body = soap.GetBody();
// close dialog
SGRSoftkeyToolbox::CloseStandardDialog(_dialog);
// redrawing
SFRApplication::GetInstance()->Invoke(
SFXEvent(SREVT_RESPONDER_RENDER,
SRP16_RENDER_INVOKE,
false));
// notify the application when connection end
_spp(NOTIFY_CONNECT_END, error, _reference);
}
return;
}
