public IActionResult Agent()
{
//mapagent only accepts GET or POST, so reject unsupported methods
bool isGet = this.Request.Method == "GET";
bool isPost = this.Request.Method == "POST";
if (!isGet && !isPost)
{
return HttpBadRequest("Unsupported method: " + this.Request.Method);
}
//We need the current request url as the mapagent may need to reference this URL for certain operations
//(for example: GetMapKml/GetLayerKml/GetFeaturesKml)
String uri = string.Empty;
try
{
//This is the workhorse behind the mapagent handler, the previously mysterious MgHttpRequest class
MgHttpRequest request = new MgHttpRequest(uri);
//MgHttpRequestParam is the set of key/value parameter pairs that you need to set up for the
//MgHttpRequest instance. We extract the relevant parameters from the HttpContext and pass it
//down
MgHttpRequestParam param = request.GetRequestParam();
//Extract any parameters from the http authentication header if there is one
bool bGotAuth = ParseAuthenticationHeader(param, Request);
if (isGet)
{
PopulateGetRequest(param, Request);
}
else if (isPost)
{
PopulatePostRequest(param, Request);
}
//A request is valid if it contains any of the following:
//
// 1. A SESSION parameter
// 2. A USERNAME parameter (PASSWORD optional). If not specified the http authentication header is checked and extracted if found
//
//Whether these values are valid will be determined by MgSiteConnection in the MgHttpRequest handler when we come to execute it
bool bValid = param.ContainsParameter("SESSION");
if (!bValid)
bValid = param.ContainsParameter("USERNAME");
if (!bValid)
{
return MgUnauthorized();
}
return SendRequest(request);
}
catch (MgException ex)
{
return HandleMgException(ex);
}
}
IActionResult SendRequest(MgHttpRequest request)
{
MgHttpRequestParam param = request.GetRequestParam();
//This next line does all the grunt work. It's why you never have to actually set up a
//MgSiteConnection/MgResourceService/MgFeatureService and do all this stuff yourself
MgHttpResponse response = request.Execute();
MgHttpResult result = response.GetResult();
Response.StatusCode = result.GetStatusCode();
if (Response.StatusCode == 200)
{
//MgDisposable is MapGuide's "object" class, so we need to do type
//testing to find out the underlying derived type. The list of expected
//types is small, so there isn't too much of this checking to do
MgDisposable resultObj = result.GetResultObject();
if (resultObj != null)
{
Response.ContentType = result.GetResultContentType();
//Most of the applicable types have logic to return their content as XML in the form of a MgByteReader
MgByteReader outputReader = null;
if (resultObj is MgByteReader)
{
outputReader = (MgByteReader)resultObj;
return OutputReaderContent(outputReader);
}
else if (resultObj is MgFeatureReader)
{
//NOTE: This code path is not actually reached in MGOS 2.4 and if this code path ever
//does get reached, calling ToXml() on it is a potentially memory expensive operation.
//
//But we're doing this because this is how the official mapagent handler does it
//
//RFC 130 (http://trac.osgeo.org/mapguide/wiki/MapGuideRfc130) will hopefully address this problem
outputReader = ((MgFeatureReader)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgSqlDataReader)
{
//NOTE: This code path is not actually reached in MGOS 2.4 and if this code path ever
//does get reached, calling ToXml() on it is a potentially memory expensive operation.
//
//But we're doing this because this is how the official mapagent handler does it
//
//RFC 130 (http://trac.osgeo.org/mapguide/wiki/MapGuideRfc130) will hopefully address this problem
outputReader = ((MgSqlDataReader)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgDataReader)
{
//NOTE: This code path is not actually reached in MGOS 2.4 and if this code path ever
//does get reached, calling ToXml() on it is a potentially memory expensive operation.
//
//But we're doing this because this is how the official mapagent handler does it
//
//RFC 130 (http://trac.osgeo.org/mapguide/wiki/MapGuideRfc130) will hopefully address this problem
outputReader = ((MgDataReader)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgStringCollection)
{
outputReader = ((MgStringCollection)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgSpatialContextReader)
{
outputReader = ((MgSpatialContextReader)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgLongTransactionReader)
{
outputReader = ((MgSpatialContextReader)resultObj).ToXml();
return OutputReaderContent(outputReader);
}
else if (resultObj is MgHttpPrimitiveValue)
{
return Content(((MgHttpPrimitiveValue)resultObj).ToString());
}
else //Shouldn't get here
{
return HttpBadRequest("Not sure how to output: " + resultObj.ToString());
}
}
else
{
//The operation may not return any content at all, so we do nothing
return Ok();
}
}
else
{
return HandleMgHttpError(result);
}
}