AddLti11Parameters

gistfile1.cs

        /// <summary>
        /// Add optional parameters that are specific to an LTI 1.1 request.
        /// </summary>
        /// <param name="assignment">The Assignment to be launched.</param>
        /// <param name="parameters">The partially filled OAuthParameters object
        /// that is being used to collect the data.</param>
        private void AddLti11Parameters(Assignment assignment, OAuthParameters parameters)
        {
            // LTI 1.1 does support custom parameter substitution
            if (!string.IsNullOrWhiteSpace(assignment.CustomParameters))
            {
                var customParams = assignment.CustomParameters.Split(new[] { ",", "\r\n", "\n" },
                    StringSplitOptions.RemoveEmptyEntries);
                foreach (var customParam in customParams)
                {
                    var namevalue = customParam.Split(new[] { "=" },
                        StringSplitOptions.RemoveEmptyEntries);
                    if (namevalue.Length == 2)
                    {
                        // Note that per the LTI 1.x specs, custom parameter
                        // names must be lowercase letters or numbers. Any other
                        // character is replaced with an underscore.
                        var name = "custom_" +
                            Regex.Replace(namevalue[0].ToLower(), "[^0-9a-zA-Z]", "_");
                        var value = SubstituteCustomValue(namevalue[1]);
                        parameters.AdditionalParameters.Add(name, value);
                    }
                }
            }

            // Basic Outcomes Service: These parameters tell the provider where to
            // send outcomes (if any) for this assignment.
            var urlHelper = new UrlHelper(Request.RequestContext);
            parameters.AdditionalParameters.Add("lis_outcome_service_url", 
                urlHelper.Action("Outcome", "Assignment", null, Request.Url.Scheme));
            parameters.AdditionalParameters.Add("lis_result_sourcedid", 
                assignment.AssignmentId.ToString());
        }