Papa Bob's Mega Solution Part 3 - Passing an Order from the Presentation Layer

Tutorial Series: Free C# Fundamentals via ASP.NET Web Apps

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This is the third part of the solution for Papa Bob's Mega Challenge. In this part of the solution, we'll be setting up the Data Transfer Object to pass an order created in the Presentation layer all the way to the Persistence layer.

Step 1: Setting up the DTO Class

Because we'll be utilizing the OrderDTO class to pass an order from the Presentation layer, we'll need to modify its properties to match those of the Entity-generated Order class of the Persistence layer. To do this, navigate to 'PapaBobsEntities' in the Persistence layer, and open its Order.cs class:


Copy all of the properties from the Order class' definition. Then, navigate to OrderDTO.cs in PapaBobs.DTO. Paste the properties from the Order class here so that it looks like this:


Step 2: Creating an OrderDTO Order in the Presentation Layer

The ultimate goal in this part of the solution is to pass an order from the Presentation layer to the database. This will happen when the orderButton_Click event is activated. Navigate to Default.aspx.cs and write the following code in the orderButton_Click to create a new instance of the OrderDTO class and then hard-code its properties:


Step 3: Passing the Order to the Persistence Layer

Now that we have an orderDTO created within this layer, we need to modify the method calls within the other layers to expect an input parameter of DTO.OrderDTO. This allows for the Presentation layer's orderDTO to be passed through the different layers.





Now, in the OrderManager's CreateOrder() method, modify the call to the Persistence, passing in the orderDTO from the input parameter:


Finally, return to Default.aspx.cs and modify the call to the Domain layer's CreateOrder(), passing in the orderDTO:


Step 4: Converting the DTO Order to an Entity Order

Now that we've passed the orderDTO to the Persistence, we need to save it to the database. However, there is an issue: The orderDTO is of a different type than an Entity Order. What we'll need to do is modify the CreateOrder() method in the Persistence layer so that it calls a helper method to convert the order into the proper type:


This modification calls a method that, at this point, has not yet been created. Select the 'convertToEntity()' text and press Ctrl + . to generate a new method stub for that method:


This method will be responsible for creating a new Entity-type order and populating its properties with those of the orderDTO that was passed in to the method:


Notice that the method's return type is changed to Order (Entity-type order), which gives the CreateOrder() method the object it needs to store in the database.

Step 5: Clear the Orders Table and Test

Before we run the project and add the order to the Orders table, make sure to clear out the table of previous data so that the new order is the only order visible in the table. To do this, open the Server Explorer, navigate to Tables and select the Orders table. Right-click and select 'Show Table Data'. From here, select the row you want to delete, right-click on the gray arrow to the left of the entry and click delete:


Then, save and run your project, click on the Order button, and return to the database to to ensure that the order was saved properly.


This concludes this part of the solution to Papa Bob's Mega Challenge. We've created much of the core functionality needed for the layers to interact and pass information back and forth. In the next part, we'll create the Default page with its controls and styling.

Related Articles in this Tutorial:

Lesson 1 - Series Introduction

Lesson 2 - Installing Visual Studio 2015

Lesson 3 - Building Your First Web App

Lesson 4 - Understanding What You Just Did

Lesson 5 - Working with Projects in Visual Studio

Lesson 6 - Simple Web Page Formatting in Visual Studio

Challenge 1

Solution 1

Lesson 7 - Variables and Data Types

Lesson 8 - Data Type Conversion

Lesson 9 - Arithmetic Operators

Lesson 10 - C# Syntax Basics

Challenge 2 - ChallengeSimpleCalculator

Solution - ChallengeSimpleCalculator

Lesson 11 - Conditional If Statements

Lesson 12 - The Conditional Ternary Operator

Challenge 3 - ChallengeConditionalRadioButton

Solution - Challenge Conditional RadioButton

Lesson 13 - Comparison and Logical Operators

Lesson 13 Challenge - First Papa Bob's Website

Solution - Challenge First Papa Bob's Website

Lesson 14 - Working with Dates and Times

Lesson 15 - Working With Spans of Time

Lesson 16 - Working with the Calendar Server Control

Challenge 4 - Challenge Days Between Dates

Solution - Challenge Days Between Dates

Lesson 17 - Page_Load and Page.IsPostBack

Lesson 18 - Setting a Break Point and Debugging

Lesson 19 - Formatting Strings

Challenge 5 - Challenge Epic Spies Assignment

Solution - Challenge Epic Spies Assignment

Lesson 20 - Maintaining State with ViewState

Lesson 21 - Storing Values in Arrays

Lesson 22 - Understanding Multidimensional Arrays

Lesson 23 - Changing the Length of an Array

Challenge 6 - Challenge Epic Spies Asset Tracker

Solution - Challenge Epic Spies Asset Tracker

Lesson 24 - Understanding Variable Scope

Lesson 25 - Code Blocks and Nested If Statements

Lesson 26 - Looping with the For Iteration Statement

Challenge 7 - Challenge For Xmen Battle Count

Solution - Challenge For Xmen Battle Count

Lesson 27 - Looping with the while() & do...while() Iteration Statements

Lesson 28 - Creating and Calling Simple Helper Methods

Lesson 29 - Creating Methods with Input Parameters

Lesson 30 - Returning Values from Methods

Lesson 31 - Creating Overloaded Methods

Lesson 32 - Creating Optional Parameters

Lesson 33 - Creating Names Parameters

Lesson 34 - Creating Methods with Output Parameters

Challenge 8 - Challenge Postal Calculator Helper Methods

Solution - Challenge Postal Calculator Helper Methods

Mega Challenge Casino

Solution - Mega Challenge Casino

Lesson 35 - Manipulating Strings

Challenge 9 - Phun With Strings

Solution - Challenge Phun With Strings

Lesson 36 - Introduction to Classes and Objects

Challenge - Hero Monster Classes Part 1

Solution - Hero Monster Classes Part 1

Challenge - Hero Monster Classes Part 2

Solution - Challenge Hero Monster Classes Part 2

Lesson 37 - Creating Class Files Creating Cohesive Classes and Code Navigation

Lesson 38 - Understanding Object References and Object Lifetime

Lesson 39 - Understanding the .NET Framework and Compilation

Lesson 40 - Namespaces and Using Directives

Lesson 41 - Creating Class Libraries and Adding References to Assemblies

Lesson 42 - Accessibility Modifiers, Fields and Properties

Lesson 43 - Creating Constructor Methods

Lesson 44 - Naming Conventions for Identifiers

Lesson 45 - Static vs Instance Members

Challenge 10 - Challenge Simple Darts

Solution - Challenge Simple Darts

Lesson 46 - Working with the List Collection

Lesson 47 - Object Initializers

Lesson 48 - Collection Initializers

Lesson 49 - Working with the Dictionary Collection

Lesson 50 - Looping with the foreach Iteration Statement

Lesson 51 - Implicitly-Typed Variables with the var Keyword

Challenge 11 - Challenge Student Courses

Solution - Challenge Student Courses

Mega Challenge War

Solution - Mega Challenge War

Lesson 52 - Creating GUIDs

Lesson 53 - Working with Enumerations

Lesson 54 - Understanding the switch() Statement

Lesson 55 - First Pass at the Separation of Concerns Principle

Lesson 56 - Understanding Exception Handling

Lesson 57 - Understanding Global Exception Handling

Lesson 58 - Understanding Custom Exceptions

Lesson 59 - Creating a Database in Visual Studio

Lesson 60 - Creating an Entity Data Model

Lesson 61 - Displaying the DbSet Result in an ASP.NET GridView

Lesson 62 - Implementing a Button Command in a GridView

Lesson 63 - Using a Tools-Centric Approach to Building a Database Application

Lesson 64 - Using a Maintenance-Driven Approach to Building a Database Application

Lesson 65 - Creating a New Instance of an Entity and Persisting it to the Database

Lesson 66 - Package Management with NuGet

Lesson 67 - NuGet No-Commit Workflow

Lesson 68 - Introduction the Twitter Bootstrap CSS Framework

Lesson 69 - Mapping Enum Types to Entity Properties in the Framework Designer

Lesson 70 - Deploying the App to Microsoft Azure Web Services Web Apps

Papa Bob's Mega Challenge

Papa Bob's Mega Solution Part 1 - Setting up the Solution

Papa Bob's Mega Solution Part 2 - Adding an Order to the Database

Papa Bob's Mega Solution Part 3 - Passing an Order from the Presentation Layer

Papa Bob's Mega Solution Part 4 - Creating the Order Form

Papa Bob's Mega Solution Part 5 - Adding Enums

Papa Bob's Mega Solution Part 6 - Creating an Order with Validation

Papa Bob's Mega Solution Part 7 - Calculating the Order Price

Papa Bob's Mega Solution Part 8 - Displaying the Price to the User

Papa Bob's Mega Solution Part 9 - Creating the Order Management Page


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