DRAG DROP
###BeginCaseStudy###
Case Study: 1
Scenario 1
Background
You are developing a flight information consolidation service. The service retrieves flight
information from a number of sources and combines them into a single data set. The
consolidated flight information is stored in a SQL Server database. Customers can query
and retrieve the data by using a REST API provided by the service. The service also offers
access to historical flight information. The historical flight information can be filtered and
queried in an ad hoc manner. The service runs on a Windows Azure Web Role. SSL is not
used.
Business Requirements
• A new data source for historical flight information is being developed by a contractor
located on another continent.
• If a time zone is not specified, then it should be interpreted as Coordinated Universal
Time (UTC).
• When you upgrade a service from a staging deployment to a production deployment,
the time that the service is unavailable must be minimized.
• The default port must be used for HTTP.
Technical Requirements
The existing sources of flight information and the mechanism of exchange are listed below.
• Blue Yonder Airlines provides flight information in an XML file.
• Consolidated Messenger provides flight information in a Microsoft Access database
that is uploaded every 12 hours to the service using SFTP. The company uses port 22 for
SFTP.
• Margie’s Travel provides and consumes flight information using serialized ADO.NET
DataSets. Data is periodically synced between the service and Margie’s Travel.
• Trey Research provides data from multiple sources serialized in proprietary binary
formats. The data must be read by using .NET assemblies provided by Trey Research. The
assemblies use a common set of dependencies. The current version of the Trey Research
assemblies is 1.2.0.0. All assemblies provided by Trey Research are signed with a key pair
contained in a file named Trey.snk, which Trey Research also supplies.
• The application specification requires that any third-party assemblies must have
strong names.
Application Structure
###EndCaseStudy###
You need to parse flight information from Blue Yonder Airlines. The content of the XML file is shown below.
Some airlines do not specify the timezone of the arrival time. If the timezone is not specified,
then it should be interpreted per the business requirements. You need to implement the
LoadFlights() and Parse() methods of the BlueYonderLoader class. What should you do?
(To answer, drag the appropriate code segments to the correct location in the answer area.
Each segment may be used once, more than once, or not at all. You may need to drag the
split bar between panes or scroll to view content.)
Answer: 
This question is garbage. none of the “answers” would actually work.
The LoadFlights() method clearly needs to be:
var flights = feed.Decendants(“{urn:CFI}Flight”).Concat(feed.Decendants(“Flight”));
The other options won’t work. However none of the last three options would actually work for the Parse() method. The one we are supposed to go for is the line with “DateTimeStyles.AssumeUniversal” in it, but this method WILL fail to execute at runtime because we know there is a namesapce involved, therefore the statement flightElement.Element(“Arrival”).Value will throw an ArgumentNullException because the namespace wasn’t appended, and the resulting XElement would be null when the Value property was dereferenced.
Semantically, it must be the one with “AssumeUniversal” in it because the others don’t do the right thing.
The answer is correct!