留学生CS 335讲解、Web Services辅导

CS 335 2019 Page 1 of 6 A#8 v1

Web Services

This assignment will give you practical experience on building a self-hosted web

service with modern frameworks, Nancy in this case. It also brings together

various bits from the previous assignments, A#5, A#6, A#7.

For a general view on Nancy, please follow the links given in the Nancy folder

and experiment with the given examples (now updated).

The server will be started on port 8081 (which is available in the labs) and will

listen at simple POST requests of the following multi-line format:

o The first line indicates a table-name, one of Customers or Orders.

o Each one of the next lines indicate a required transformation - in a format

similar to the one used in A#7.

Our application contains a folder called data, where we have two XML serialised

versions of the “standard” Northwind tables Customers and Orders, here

called Customers.XML and Orders.XML (respectively).

Essentially, we have to parse the XML “tables” into corresponding collections,

apply the required transformations, in the given order, and finally return the

result as a JSON formatted response.

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For parsing XML, we recommend extension methods from the System.Xml.Linq

namespace, such as .Elements (name), .Element (name).

The XML data must be parsed into objects of this format, exactly (otherwise the

request may fail):

public class Customer {

public string CustomerID { get; set; }

public string CompanyName { get; set; }

public string ContactName { get; set; }

}

public class Order {

public int OrderID { get; set; }

public string CustomerID { get; set; }

public DateTime? OrderDate { get; set; }

public DateTime? ShippedDate { get; set; }

public decimal? Freight { get; set; }

public string ShipName { get; set; }

public string ShipCity { get; set; }

public string ShipCountry { get; set; }

// more about this field later:

public Customer Customer { get; set; }

}

Note that Order has three nullable properties (?), which need special care when

parsing! For the moment, also ignore the property Order.Customer.

The required transformations use method names as in A#7, i.e., Where,

Select, OrderBy, Take, Skip, which means that you can still use Dynamic

Linq.

However, the element types of the sequences can be arbitrary tuples (not just

strings as in A#7).

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The assignment has several levels of difficulty, which will be separately

assessed.

Level 1 – 4 marks

We should be able to work with transformations starting from the Customers

table. For example:

POST Request Body:

Customers

OrderBy ContactName DESC

Where CustomerID < "D"

Take 3

Select new (CustomerID, ContactName, CompanyName)

POST Response (minified):

[{"customerID":"CHOPS","contactName":"Yang

Wang","companyName":"Chop-suey

Chinese"},{"customerID":"BSBEV","contactName":"Victoria

Ashworth","companyName":"B's

Beverages"},{"customerID":"AROUT","contactName":"Thomas

Hardy","companyName":"Around the Horn"}]

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Level 2 – +2 marks (total 6 marks)

We should also be able to work with transformations starting from the Orders

table, which do NOT use the nullable fields (so you can start by ignoring these

while parsing). For example:

POST Request Body:

Orders

OrderBy OrderID

Take 3

Select new (OrderID, ShipCountry, CustomerID)

POST Response (minified):

[{"orderID":10248,"shipCountry":"France","customerID":"VINET"},{"orde

rID":10249,"shipCountry":"Germany","customerID":"TOMSP"},{"orderID"

:10250,"shipCountry":"Brazil","customerID":"HANAR"}]

Level 3 – +1 marks (total 7 marks)

We should also be able to work with transformations starting from the Orders

table, which DO use the nullable fields (so now you need to parse the fields). For

example:

POST Request Body:

Orders

Where OrderDate != null && (ShippedDate == null || Freight == null)

Take 3

Select new (OrderID, OrderDate, ShippedDate, Freight)

POST Response (minified):

[{"orderID":11008,"orderDate":"1998-04-

08T00:00:00.0000000+12:00","shippedDate":null,"freight":79.4600},{"o

rderID":11009,"orderDate":"1998-04-

08T00:00:00.0000000+12:00","shippedDate":null,"freight":59.1100},{"o

rderID":11010,"orderDate":"1998-04-

09T00:00:00.0000000+12:00","shippedDate":null,"freight":28.7100}]

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Level 4 – +1 marks (total 8 marks)

We should also be able to work with transformations that require navigation

from the Orders table to the associated Customer, which means that you have

to conceptually “join” the two tables and set the Order.Customer link. For

example:

POST Request Body:

Orders

OrderBy OrderID

Take 3

Select new (OrderID, ShipCountry, CustomerID, Customer.ContactName,

Customer.CompanyName)

POST Response (minified):

[{"orderID":10248,"shipCountry":"France","customerID":"VINET","contact

Name":"Paul Henriot *******","companyName":"Vins et alcools

Chevalier"},{"orderID":10249,"shipCountry":"Germany","customerID":"T

OMSP","contactName":"Karin Josephs","companyName":"Toms

Spezialitäten"},{"orderID":10250,"shipCountry":"Brazil","customerID":"H

ANAR","contactName":"Mario Pontes","companyName":"Hanari Carnes"}]

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Programs:

(A#8) one single file C# solution (required).

You can of course use all standard libraries extant in the labs, plus Nancy.dll,

Nancy.Hosting.Self.dll, DynamicLinqUoA.dll.

Please don’t forget to add proper using clauses to your source program.

Submission

Please submit to the COMSPCI ADB (not to automarker).

https://adb.auckland.ac.nz/