/// <summary>
/// Create an LtiRequestViewModel that contains a ContentItemPlacementResponse.
/// </summary>
/// <param name="url">The content_item_return_url from the content-item message.</param>
/// <param name="consumerKey">The OAuth consumer key to use to sign the request.</param>
/// <param name="consumerSecret">The OAuth consumer secret to use to sign the request.</param>
/// <param name="contentItems">The ContentItemPlacementResponse to send.</param>
/// <param name="data">The data received in the original content-item message.</param>
/// <param name="ltiErrorLog">Optional plain text error message to be logged by the Tool Consumer.</param>
/// <param name="ltiErrorMsg">Optional plain text error message to be displayed by the Tool Consumer.</param>
/// <param name="ltiLog">Optional plain text message to be logged by the Tool Consumer.</param>
/// <param name="ltiMsg">Optional plain text message to be displayed by the Tool Consumer.</param>
/// <returns>The LtiRequestViewModel which contains a signed version of the response.</returns>
public static LtiRequestViewModel CreateContentItemSelectionViewModel(
string url, string consumerKey, string consumerSecret,
ContentItemSelectionGraph contentItems, string data,
string ltiErrorLog, string ltiErrorMsg, string ltiLog, string ltiMsg)
{
var ltiRequest = new LtiRequest(LtiConstants.ContentItemSelectionLtiMessageType)
{
Url = new Uri(url),
ConsumerKey = consumerKey,
ContentItems = contentItems.ToJsonLdString(),
Data = data,
LtiErrorLog = ltiErrorLog,
LtiErrorMsg = ltiErrorMsg,
LtiLog = ltiLog,
LtiMsg = ltiMsg
};
return ltiRequest.GetViewModel(consumerSecret);
}
public ActionResult PlaceContentItem(int id)
{
var tool = ProviderContext.Tools.Find(id);
if (tool == null)
{
return RedirectToAction("BadRequest", "Error", new { error = "Invalid tool id" });
}
var ltiRequest = GetLtiRequestFromClaim();
if (ltiRequest == null)
{
return RedirectToAction("BadRequest", "Error", new { error = "Invalid LTI request" });
}
var consumer = ProviderContext.Consumers.SingleOrDefault(c => c.Key.Equals(ltiRequest.ConsumerKey));
if (consumer == null)
{
return RedirectToAction("BadRequest", "Error", new { error = "Invalid consumer" });
}
// Prepare the custom parameters this TP would like on each link.
var custom = new Dictionary<string, string>();
// The next two custom parameters use well-known custom parameter substitution variables.
custom.Add("username", "$User.username"); // Used by this TP when pairing a new user
custom.Add("tc_profile_url", "$ToolConsumerProfile.url"); // Used by this TP to determine TC capabilities
// Determine the best PresentationDocumentTarget from the list of targets acceptable
// to the TC assuming the TC sent the list of acceptable targets in priority order
var presentationDocumentTarget = DocumentTarget.iframe;
var acceptablePresentationDocumentTargets =
ParseDocumentTargets(ltiRequest.AcceptPresentationDocumentTargets);
if (acceptablePresentationDocumentTargets.Count > 0)
{
if (!acceptablePresentationDocumentTargets.Contains(presentationDocumentTarget))
{
presentationDocumentTarget = acceptablePresentationDocumentTargets[0];
}
}
// Calculate the full qualified URL for the tool.
var toolUrl = UrlHelper.GenerateUrl("Default", "View", "Tool", new RouteValueDictionary(new { id }),
RouteTable.Routes, Request.RequestContext, false);
Uri toolUri;
Uri.TryCreate(Request.Url, toolUrl, out toolUri);
// Start building the response
var graph = new List<ContentItem>
{
new LtiLink
{
Custom = custom,
Id = toolUri,
MediaType = LtiConstants.LtiLinkMediaType,
Text = tool.Description ?? ltiRequest.Text,
Title = tool.Name ?? ltiRequest.Title,
PlacementAdvice = new ContentItemPlacement
{
PresentationDocumentTarget = presentationDocumentTarget
}
}
};
var response = new ContentItemSelectionGraph
{
Graph = graph
};
// Content-Item Message 1.0 sends each request (which can have many items)
// back to the Tool Consumer.
var model = ContentItemsClient.CreateContentItemSelectionViewModel(
ltiRequest.ContentItemReturnUrl, consumer.Key,
consumer.Secret, response, ltiRequest.Data,
null, null, null, "Selected " + tool.Name);
return View(model);
}
/// <summary>
/// Create an LtiRequestViewModel that contains a ContentItemPlacementResponse.
/// </summary>
/// <param name="url">The content_item_return_url from the content-item message.</param>
/// <param name="consumerKey">The OAuth consumer key to use to sign the request.</param>
/// <param name="consumerSecret">The OAuth consumer secret to use to sign the request.</param>
/// <param name="contentItems">The ContentItemPlacementResponse to send.</param>
/// <param name="data">The data received in the original content-item message.</param>
/// <returns>The LtiRequestViewModel which contains a signed version of the response.</returns>
public static LtiRequestViewModel CreateContentItemSelectionViewModel(
string url, string consumerKey, string consumerSecret,
ContentItemSelectionGraph contentItems, string data)
{
return CreateContentItemSelectionViewModel(url, consumerKey, consumerSecret, contentItems, data, null, null, null, null);
}
