The purpose of the Symphony Framework is to enable you to expose existing Synergy data and logic in a way that can be utilised in a Windows Presentation Foundation (WPF) desktop application. This is achieved using Symphony Data Objects. These Data Objects are at the root of a Symphony Framework development.
Creating a Symphony Data Object is very simple, but before we talk about how, let’s look at why. Synergy data is rather different to the data you find in other applications/databases. All synergy data is an alpha. When I talk about Synergy data I mean the information we store and move around the application. I’m not referring to individual elements of data that you can define using the “data” statement – these are different and do allow you to create a data entity that is not an alpha. So, that’s cleared up what “data” in Synergy is…. It’s all just an alpha. These alpha data areas are what we manage in our SDMBS data files. Just try reading from your file into an integer: %DBL-E-ALPHAXP, Alpha expression expected! The compiler is very clever and allows you to re-map this alpha data to anything you desire, with a few exceptions, and this is done by declaring “record” areas. Your record area can overlay this alpha data in any way you require, and can even overlay the overlays. This overlaying is simply remapping how we want to expose or access the individual bytes of the alpha stream of data. It’s actually quite cool and very powerful. Now you have your alpha data – but in your Synergy program you are accessing portions of the data as different types like decimal, integer, alpha, etc. and your programs rely on this ability. So where do we store these overlay definitions of our alpha data – in your Synergy Repository of course!
Now back to our Symphony Data Objects. As I mentioned, creating them is a breeze. You simply use CodeGen, the right Symphony Framework template, and your Synergy Repository structure. The syntax is very easy:
codegen -s GROUP -t Symphony_Data -n PartMaint -prefix m
And you have your structure based Symphony Data Object.
Assuming you have referenced the required Symphony Framework assemblies in your Synergy.NET Visual Studio project your Data Object code will just build.
Understanding the Data Object is really quite simple as well. There are a number of aspects to be aware of….
- There is a property called SynergyRecord. This is a property that exposes the underlying “alpha” data area. You can use this property to populate the Data Object, for example, when you have read a record from a file.
- Each field in your repository structure is exposed as a read-write property which allows access to the individual fields.
- You can data-bind to these properties from your WPF user interface (XAML) code. More about this in my next article!
- You can also access this “field” data from your existing Synergy code.
- Additional powerful capabilities of your Data Object include:
- IsDataValid is a boolean value indicating if the data within the Data Object passes the basic validation rules you have defined in your repository structure. For example, a “required” field must have a value in it otherwise the Data Object is considered IsDataValid == false.
- The object conforms to the property notification sub-system of the Model-View-ViewModel design pattern for WPF development.
- Individual fields in your repository structure additionally expose IsEnabled, IsReadOnly and IsFocused properties that help you control the User Interface.
You can watch a short video at http://youtu.be/DkoVIEmr3NY that walks you through the steps for creating Symphony Data Objects and building them into your Synergy .NET Visual Studio project. In the next article I’ll demonstrate how easy it is to data bind UI controls to your Data Object properties.