Contents
This topic discusses the options for preserving the layout information of components on the EventFlow Editor canvas.
The EventFlow XML grammar contains two distinct types of elements:
- EventFlow Semantic elements
-
Describes the functionality of application components. This information changes when you add or remove components and change their properties.
- Graphical Layout elements
-
Describes the last-saved graphical positions and dimensions of components on the EventFlow canvas. This information changes when you move or resize a component on the canvas. Changes in layout elements have no effect on your application's functionality.
By default, StreamBase stores semantic and layout elements in in separate files:
-
Semantic elements stored in the primary application file with
.sbappextension. -
Layout elements stored in an associated layout-only file with
.sblayoutextension.
When a separate layout file exists for an application module, it shares the same base
name, which always matches exactly in spelling and case. For example,
StreamBase Studio treats the following files as a related pair that
together define the application module BlendDepthOfBook:
BlendDepthOfBook.sbapp
|
BlendDepthOfBook.sblayout
|
StreamBase Studio respects and preserves the layout status it detects for each individual EventFlow application. That is:
-
If Studio detects an
.sbappfile with no matching.sblayoutfile, then it draws the canvas based on the layout information in the.sbappfile. On save, Studio creates the matching.sblayoutfile and stores all layout information there. -
If Studio detects an
.sbappfile with matching.sblayoutfile (with the same base name), then it uses the layout information in the.sblayoutfile to draw the canvas. On save, Studio stores any changed layout information back to the.sblayoutfile.
Your project folders might contain several EventFlow application modules with a mix
of layout states: some modules with only an .sbapp
file, and other modules with both .sbapp and
.sblayout files.
Separate layout files are copied and deleted automatically when you copy or delete
the corresponding EventFlow file. If you rename the EventFlow file with refactoring,
its corresponding .sblayout file is automatically
renamed. But the reverse is not true: you can copy, delete, and rename .sblayout files without affecting the corresponding EventFlow file.
StreamBase Studio's default state for newly created EventFlow modules is to keep semantic and layout information in separate files. The advantages are:
-
Better match for many version control systems. With meaningful changes isolated to the
.sbappfile, difference comparison and merging are easier for version control systems to handle. -
Easier to share application modules in a team development environment, where more than one developer might open the same file and rearrange components.
The advantage of using combined layout in the .sbapp
file is simplicity of file management and in sharing of application module files with
other users.
There are both manual and automatic ways to create an .sblayout file for any .sbapp file.
- Manual Creation of Layout Files
-
Create separate layout files for individual EventFlow applications with the following steps:
-
Select one or more
.sbappfile names in the Package Explorer. (Hold the Ctrl key while clicking to select more than one.) You can select files in the same project or different projects. -
Right-click and select → → from the context menu.
-
- Automatic Creation of Layout Files
-
Configure Studio to automatically create separate layout files when new EventFlow application files are created:
-
Open Studio Preferences with → .
-
In the contents pane on the left, open → .
-
Select Separate layout (.sblayout) file (the default setting).
This setting controls only whether
.sblayoutfiles are created automatically when you create EventFlow application files going forward. It does not affect existing.sbappfiles in your workspace. -
When a module has separate .sbapp and .sblayout files, you can recombine the two by removing the
.sblayout file in the Package Explorer. In this case,
Studio behaves as follows:
-
If the
.sbappfile is open in Studio when you remove the.sblayoutfile, Studio detects a file system change and prompts for permission to reload the file. Let the file reload, then move one component slightly, which allows you to save the.sbappfile. When you next save the module, the current layout information is saved to the.sbappfile. -
If the
.sbappfile is not open when you remove the.sblayoutfile, then the next time the.sbappfile is opened, Studio applies a default layout. Rearrange the components as you prefer, then save the file.