/// <summary>
/// Verifies the extension rule.
/// </summary>
/// <param name="context">The Interop service context</param>
/// <param name="info">out parameter to return violation information when rule does not pass</param>
/// <returns>true if rule passes; false otherwise</returns>
public override bool?Verify(ServiceContext context, out ExtensionRuleViolationInfo info)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
bool?passed = null;
ExtensionRuleResultDetail detail = new ExtensionRuleResultDetail(this.Name);
var restrictions = AnnotationsHelper.GetChangeTracking(context.MetadataDocument, context.VocCapabilities);
if (string.IsNullOrEmpty(restrictions.Item1) ||
null == restrictions.Item2 || !restrictions.Item2.Any() ||
null == restrictions.Item3 || !restrictions.Item3.Any())
{
detail.ErrorMessage = "Cannot find an entity-container or any entity-sets which support the change tracking function.";
info = new ExtensionRuleViolationInfo(context.Destination, context.ResponsePayload, detail);
return(passed);
}
string url = string.Format("{0}/{1}", context.ServiceBaseUri, restrictions.Item1);
List <KeyValuePair <string, string> > requestHeaders = new List <KeyValuePair <string, string> >();
foreach (KeyValuePair <string, string> kvp in context.RequestHeaders)
{
requestHeaders.Add(new KeyValuePair <string, string>(kvp.Key, kvp.Value));
}
// Add odata.track-changes preference in request header.
KeyValuePair <string, string> prefer = new KeyValuePair <string, string>("Prefer", "odata.track-changes");
requestHeaders.Add(prefer);
Response response = WebHelper.Get(new Uri(url), Constants.V4AcceptHeaderJsonFullMetadata, RuleEngineSetting.Instance().DefaultMaximumPayloadSize, requestHeaders);
detail = new ExtensionRuleResultDetail(this.Name, url, "GET", StringHelper.MergeHeaders(Constants.V4AcceptHeaderJsonFullMetadata, requestHeaders), response);
if (response != null && !string.IsNullOrEmpty(response.ResponseHeaders))
{
string preferHeader = response.ResponseHeaders.GetHeaderValue("Preference-Applied");
if (string.IsNullOrEmpty(preferHeader))
{
passed = false;
detail.ErrorMessage = "The response header returned by the service does not contain 'odata.track-changes', when request with the header 'Prefer:odata.track-changes'.";
}
else if (preferHeader.Contains("odata.track-changes"))
{
passed = true;
}
}
else
{
passed = false;
detail.ErrorMessage = "The service does not support Delta change tracking.";
}
info = new ExtensionRuleViolationInfo(context.Destination, context.ResponsePayload, detail);
return(passed);
}