(Building the Presentation Layer - KISS)

Figuring out what to do! Every was not learnt over night and certainly not without proper help and support.

Tools to Help us We are… Taking time to think about the problem Working collaboratively Using documentation to help us model the problem System specification Event tables Use case diagrams / descriptions Class diagrams Using tools to support us (Enterprise Architect and Visual Studio)

Additional Tools Visual Studio on-line Paper based designs Smoke and mirrors prototype Test Driven Development

Visual Studio On-Line A tool to allow you to share code between members of your team Includes version control to ensure that you have the most up to date version of your code

Implementing the Use Cases At some point we will need to turn our use case diagrams into presentation layer artefacts. In creating a web based interface this will involve ASP.NET web forms. In creating a desktop application this will require a Windows executable file using Windows forms.

Paper Based Designs Pen and paper is fast and cheap If your design is way off the mark of the client’s expectations then it isn’t too painful to change it I often use rough scribbles on paper just to plan out ideas if I am not sure what I need to do May be turned into story boards

The Smoke and Mirrors Prototype Firstly it is a tool to allow you to mock up the system to the client quickly with a minimum of effort on your part. Secondly it provides a useful discussion point with the user / client to establish if you are on the correct track. Even the most experienced of developers have incorrect assumptions about user interaction.

For example…

The DVD swap shop

Response.Redirect Used to transfer us between web forms

.Visible.Enabled &.Text Properties

The Benefits of Prototyping Show your system design to your client to see if it is what they are looking for Created very quickly and easily modified to suit the needs of your client Should look like a professional piece of software however the functionality is just an illusion Once you know that your prototype design is suitable then you may get on with the task of making the code work However – now that you have your presentation layer clearly defined it provides a bigger insight into how the middle layer code will need to work along with the sort of tables and attributes the data layer will need

Solutions and Projects in Visual Studio A slight tangent perhaps… As we saw in the lab last week Visual Studio allows us to create projects and solutions A project may be a web site, a desktop application, an application based in the cloud, a mobile phone app, class library etc. In Visual Studio we have the option of adding projects to a solution A solution is a master container that allows us to work on multiple projects at the same time also to create a single class library and link that class library to the projects in the solution

New Architecture PBFrontEnd (Interface) Data Layer Database Middle Layer Business Logic (Classes) PBBackOffice (Interface)

Allowing us to Share Data Between Multiple Projects…

Thick and Thin Layers When we are creating any code it is always a good idea to write with an eye to re-use. Any code in the middle layer class library may be shared across multiple projects Any code that is in the presentation layer is much harder to share with other projects We want to create as little code in the presentation layer as possible

The Class Diagram We will think about the code that handles the collection class clsAddressCollection - clsAddress

Populating a List With a Loop

Keep the Presentation Layer Simple

Prototype Presentations Marking Scheme Grade Personal appearance Clarity of delivery Timing of delivery Subjective enjoyment Consideration of potential users Completeness of documentation