The Missing Link: Schema Modeler for Mac

In this previous post, i talked about the current state of Data Abstract for OS X, and also promised a follow-up with a roadmap of where we are going next.

Where We’re at

To recap, when Data Abstract for OS X originally shipped last winter, it was client only. Basically, you needed to have existing servers written in DA/.NET or DA/Delphi (or write new ones using those same tools). This basically made DA/OSX a solution mainly for our existing Delphi and .NET customers, allowing them to expand their current solutions with native Mac and iPhone clients

In the following Spring release last month, we added Relativity Server running on all three platforms, giving developers the option to host Data Abstract services on Mac (in addition to Linux and Windows), without needing to know .NET or Delphi (or even having those tools).

This took care of two thirds of the picture, but there is still one hole in a complete Mac solution: Schema Modeling (and Relativity Administration). While Relativity server runs on the Mac, developers are still dependent on Windows based tools both to configure and control their Relativity server, and – more importantly – design and work with their schemas.

What’s Coming Next

As hinted at before, we’re working on closing this gap, and are writing a new tool for Mac developers that provides two things. First, it builds on the functionality in Relativity Server Admin for Windows, and expands it to a new concept, to what we are calling the Server Explorer. Secondly, it will allow Schema Modeling thru Relativity server, essentially providing the full functionality of Schema Modeler for Windows.

Let’s have a quick look at both of these aspects.

Server Explorer

Server Explorer will provide a single unified place for you to keep track of and administer all your Data Abstract servers. You can see a preview of what the current beta of Server Explorer looks like, here: (note that many things may still be subject to change before this ships):

Server Explorer will automatically find ZeroConf servers on your local network, and you can manually register servers at remote locations, using their Target URL. It can handle Relativity and custom servers alike, although it will show slightly different options and features for each.

In the screenshot you see two servers folded open – one custom server (this is our Continuous Integration system, OnyxCI), and one Relativity server.

Custom DA servers don’t provide much room for configuration, so Server Explorer restricts itself to showing a list of all services it finds, and allowing you to browse data (including running DA SQL queries, if the server supports it) and view the readonly schema. That is provided you have a login to the server that authorizes data access. In this case, you can see there’s 2 data services and four other services exposed by our server.

For Relativity servers, there’s a lot more to see. As the screenshot shows, you can dive into the different Domains configured on the server (we’re looking at one called “OneSpace” here, which is a personal project of mine). You can look at the schemas (as well as browse and query the data they expose) and connection strings, and you can of course configure the Relativity server itself, such as to create new Domains.

Where things get interesting is on the Connection and Schema nodes, both of which allow you to open dedicated editor documents for what essentially are the .daConnections and .daSchema files.

Schema Modeler

Combined, these two editors give you the same abilities you have in Schema Modeler for Windows: You can define new connections and browse the actual contents of the database they connect to. And you can visually create and edit schemas, both by manually defining data tables and other elements, or by dragging tables from a Connection to the Schema document.

There is two core differences between what you (may) know from Schema Modeler for Windows, and how the Mac version of Schema Modeler handles things.

For one thing, while DASM/Win combines both the Schema and the Connection list into a single document window, DASM/Mac keeps them separate. The reason is simply that a Domain has one list of connections, but might have more than one schema defined. Having both in separate windows makes it more intuitive to edit several schemas at the same time – you will have one shared Connections window, where you can edit the connections, and from which you can drag objects into any of the schemas.

The second difference is more important. The current DASM/Win contains both DA/.NET and DA/Delphi server code that talks directly to the databases to retrieve metadata such as table names. If you are writing a Delphi server, it uses DA/Delphi drivers, if you are writing a .NET server or creating a schema for Relativity, it uses DA/.NET ones. This logic is embedded right into DASM/Win.

For DASM/Mac we have changed this, and have moved modeling support into the Relativity server. Relativity now exposes APIs (password protected, of course) that allow Schema Modeler to create connections for and obtain meta data from any database supported by the instance of Relativity it is talking to – over the network.

This means that you don’t need to worry about the proper drivers being installed and properly configured on your development machine, it also means that your database does not even have to be exposed to the network your development machine is on (you might have both your Relativity server and the backend database hosted somewhere on the internet, and expose only Relativity thru the firewall, for example. As long as you can talk to your Relativity server, you can work).

As a side effect, this allows Schema Modeler to be a 100% native Cocoa application and to still model and validate schemas against all the DA/.NET drivers available in Relativity.

As you can see in the screenshot of the Schema document above, DASM/Mac also already exposes the new DA Scripting feature, which allows you to use JavaScript to define business rules that will run inside Relativity (but also in custom DA Servers).

The Add Event drop down provides quick access to stubs for all the available events, in this case the schema implements (well, pretends to) the beforeProcessDelta event, which gets called before any chunk of updates received from the client would be applied


Work on DASM/Mac is well under way, and we’re confident it will ship with the upcoming “Summer 2010” releases. The same is true for DA Scripting in DA/.NET and Relativity (the feature is completed as we speak).

Stay tuned to see both features in beta drops, very soon.


marc hoffman

Chief Architect and CEO here at RemObjects Software. Project Manager for Elements and lead developer of Fire, our awesome new development environment for the Mac.