Review the Project Explorer

The Project Explorer shows both an object-based and a file-based view of all the projects in the workspace.

  1. In Project Explorer, note that you can expand and collapse MyProject by clicking the twisty on the left.
    The next level shows namespaces (only one, in this case), a dependencies entry, and resources (directories and files).
    Below the namespace, my.name.space, are main composites. Other objects, such as types and functions, if you had any, appear there also.
  2. Under my.name.space, see the main composite MyMainComposite.
    The next level shows build configurations. Here, there is only one build configuration, named BuildConfig, that is created by default. You can create multiple builds, for debug, different optimization levels and other variations.
  3. Expand Resources.
    The next level shows a number of directories and two XML files that contain descriptions of the current application or toolkit. (In Streams, toolkit and application are the same in terms of project organization and metadata.)
    The only directory you will use in this lab is the data directory. By default, build configurations in Streams Studio specify this as the root for any relative path names (paths that do not begin with a forward slash “/”) for input and output data files.

Default data directory

Streams applications do not have a default data directory unless you explicitly set one in the build specification. Here, you are simply taking advantage of a feature of Streams Studio, which will provide that specification by default. It works because you have only a single host.

Because Streams is a distributed platform that does not require a shared file system, you need to be careful when you specify file paths. A process accessing a file must run on a host that can reach it. In general, this means specifying absolute paths and constraining where a particular process can run. Using relative paths and a default data directory makes the application less portable.