EventFlow Editor

Each component in the Editor tab has an associated Properties view, where you can view and define the properties of the selected component. See Properties View for more on using the Properties view.

This section describes specialized commands that you can use while working in the EventFlow Editor canvas. The availability of each command depends on your selection, focus, or mouse position within the canvas. Many of these commands are available in multiple places: a StreamBase Studio menu, in the right-click context menu, or a toolbar button. The following table is in alphabetical order by command name.

Command	Description	Context menu	StreamBase Studio menu	Toolbar button[a]
Add Note	Creates a note associated with one or more selected components. See Notes.	Yes	Diagram	No
Add Input Stream To Port n	Available only if your mouse is over the input port of a component. Creates an input stream attached to the specified port. This is a quicker alternative to dragging an input stream from the Palette.	Yes	No	No
Add Output Stream To Port n	Same as above, but for output streams.	Yes	No	No
Center Selection	Available when one or more components in the Editor are selected. Centers the view in the Editor with the selected component in the center of the new view.	Yes, with components selected	Diagram	No
Compare Schemas	Only appears in the context menu when you have selected two arcs or two streams in the canvas. Opens the Compare Schemas dialog as described in Compare Schemas	Yes, with two arcs or two streams selected	No	No
Create Group	Creates a group containing the select components. See Groups.	Yes, with two or more components selected	No	No
Disable Arc	Disables the selected arc and all downstream components. Tuples arriving at the beginning of a disabled arc are not passed to its end. See Commenting Out.	Yes	No	No
Disable Component	Disables the selected component, including all input and output ports, and all downstream components. See Commenting Out.	Yes	No	No
Enable Arc	Only appears in the context menu when the current selection is a disabled arc. Re-enables the disabled arc. See Commenting Out.	Yes	No	No
Enable Component	Only appears in the context menu when the current selection is a disabled component. Re-enables the disabled component. See Commenting Out.	Yes	No	No
Export view as PNG	Allows you to save the currently visible portion of the current EventFlow Editor, at its current zoom level, to an image file in portable network graphics format. Opens the Export Visible Diagram as PNG dialog, in which you specify a name for the image file. You can navigate anywhere in your file system to save the image file.	Yes	No	No
Export Application Bundle	Creates an application bundle file, as described in Application Bundling	Yes, on the StreamBase menu	File → Export → StreamBase	No
Extract As Module	Replaces the selected components in the EventFlow with a Module Reference, and creates a new application in the current project folder. The Module Reference points to the new application, which contains the selected components. See Extracting an Application Module.	Yes, with two or more components selected	Diagram	No
Insert Operator	Only appears in the context menu when you have selected an arc. Allows you to replace the selected arc in one step with a Filter, Map, Split, or Union operator, with arcs drawn from the newly added operator to the upstream and downstream components.	Yes, when one arc is selected	No	No
Layout Application	Rearranges the EventFlow's components and connections.	No	Diagram
Open Declaration	When a Module reference is selected, opens the EventFlow file that defines that module. When the icon for a custom Java operator or adapter is selected, opens the Java source file for that Java operator or adapter, if the source is available in the current Studio workspace. (Source for StreamBase-provided operators and adapters is not in your workspace, and cannot be opened.)	Yes	Diagram	No
Open in Properties View	If a single component is selected, opens its Properties view.	Yes	No	No
Quick Outline	Displays the whole application's components and details in a Quick Outline window. See Quick Outline.	Yes	Diagram	No
Refresh Project Typecheck Environment	If you have Java code in the current project (for example, as part of a custom operator or adapter), run this command when you have changed any Java code, to force the EventFlow to reread the changed Java code.	Yes	No	No
Reroute Connections	Rearranges the EventFlow's connections around components.	No	Diagram
Save Schema	If a stream is selected, opens the Save Schema dialog. See Using Saved Schemas.	Yes	No	No
Typecheck	Typechecks the selected components in the EventFlow Editor, or the entire EventFlow, if no components are selected.	No	Diagram
Undo Edit	Reverse changes to the last edited component.	Yes	Edit	No
View Source	Displays the a pop-up window showing the XML source of the current EventFlow. If a single component is currently selected, the window contains the XML source code for that component only. If you select zero or multiple components, the entire application is shown. To hide GUI-related code (which has no functional effect) in the View Source window, check the Filter non-semantic elements checkbox.	Yes	Diagram	No
Zoom In	Increments the zoom factor of the entire EventFlow, making details larger. If the application becomes larger than the Editor window, scroll bars are displayed. If your Windows or Linux computer has a mouse with a scroll wheel (or a touchpad that emulates a scroll wheel), and the wheel is enabled, then Ctrl + Mouse Wheel also zooms in. For this feature to work, you must click anywhere in the EventFlow editor canvas to select it.	Yes	Diagram
Zoom Out	Decrements the zoom factor of the entire EventFlow, making details smaller. Ctrl + Mouse Wheel also zooms out. See the note directly above.	Yes	Diagram
Zoom to Fit	Zooms the entire EventFlow in or out to fit within the EventFlow Editor.	No	Diagram
[a] The StreamBase toolbar is described in Toolbar Reference.

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You can comment out or disable a branch of an EventFlow application. You might do so when trying to isolate a problem, or you might disable portions of an application during development that are only needed at deployment time.

Disable an arc by selecting Disable Arc from the context menu. Re-enable with Enable Arc on the context menu of a disabled arc. You can also select an arc and press Ctrl+/. This keyboard shortcut is a toggle, so you can use it to quickly disable and re-enable arcs and components.

Disabling an arc prevents tuples from reaching the end of the arc, and automatically disables all downstream components. Disabled arcs can still have breakpoints. Disabled components are shown greyed out on the EventFlow canvas, as in the following example:

You can disable components with Disable Component from the context menu. This disables all of the selected component's input and output ports, and all components downstream.

If a component has more than one input port and you disable one port, the component is partially disabled and still processes tuples through its enabled ports. Partially disabled components appear in the canvas marked with a light yellow background, as in the following example:

When converting an EventFlow module to StreamSQL, any portions of the module that are commented out do not appear in the generated StreamSQL file. If you intend to convert an entire EventFlow file to StreamSQL, enable all disabled components before the conversion.

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Quick Outline is a pop-up summary of the components in the current EventFlow, and is a faster alternative to the Outline view. Use the Quick Outline feature to:

To open a Quick Outline for the currently active EventFlow view, use one of these methods:

The Quick Outline pop-up window has two panes:

To navigate with the Quick Outline window, use the component tree or edit field to locate a component of interest. When located and selected, press Enter. This closes the Quick Outline, centers the EventFlow diagram on the selected component, and, if necessary, increases the zoom factor so that the selected component is clearly visible.

To close a Quick Outline, press Esc, or change focus to anywhere in StreamBase Studio outside the Quick Outline.

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To compare the schemas of two arcs or two streams in the canvas, hold down the Ctrl key and select two arcs or two streams. Comparing schemas is best used on closely related schemas, such as an old and new version of the same schema. The comparison is more meaningful if one of the selected arcs or streams is downstream of the other in the same flow of tuples.

With two arcs or streams selected, right-click and select Compare Schemas from the context menu. Compare Schemas only appears in the context menu under these selection conditions.

This opens the Compare Schemas dialog, which shows a side-by-side view of the schemas of the two selected components. Use this feature to see what fields are added or removed in schemas as tuples flow downstream. Check the Ignore field order checkbox to compare for the presence of like fields, regardless of field order.

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You can group collections of components on your canvas, drawing a box with a colored background around the selected components. You can collapse the contents of a group to a single icon on the canvas.

Groups are a visual tool that can help you edit more efficiently, but they do not affect the functionality of your application. See Using Groups for more on groups.

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To document your EventFlows, you can add Notes. Notes can attach to the EventFlow canvas, to individual components, to two or more components selected together, or to Groups. It is even possible to attach a Note to another Note. See Using Notes for more on notes.

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For quickly viewing properties without modifying them, StreamBase provides an extensive set of tooltips. If tooltips are enabled (the default setting), StreamBase Studio displays key properties for each component when you hover your cursor over it (sometimes called mouseover). The contents of each tooltip depends on the component type and the location of the cursor on the component's icon.

This section describes how properties of some components are shown using tooltips. In the screens that follow, the relevant component is indicated by the mouse pointer. The subsections are:

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Operator Tooltips

Here are some examples of tooltips for different operators. Notice how the information varies with each operator.

For the Bsort operator, the tooltip shows its name, component type, and describes the sort operation defined.

For the Filter operator, the tooltip displays the predicate (boolean expression) that corresponds to each output port.

For the Join operator, the tooltip tells you that the join is by value (instead of by tuples), shows the predicate (boolean expression) to be applied, and all the other settings defined in the Properties view.

For the Query Table, the tooltip tells you whether the table is in-memory or on-disk, as well as its index fields and schema.

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Port Tooltips

Each port on a component is depicted as a black square. The tooltip for an input port on the left side or an output port on the right side displays the port's number. For example:

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Tooltips for Streams and Arcs

The tooltip for an arc between components displays the schema of the tuples on that arc (if known). For example:

In some arc tooltips, the text not null is appended to fields that cannot have a null value. The text is informational, not part of the actual field name or value. In the example below, the timestamp field coming out of the Heartbeat operator will always have a value. In the output stream's tooltip, the same field would not have this text, because it is possible for the intervening operator to change it to a null value.

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Toggling Tooltip Properties and Comments

If you have added comments in the General tab of the Properties view of a component (a good documentation practice), the tooltip displays those comments by default instead of the component's properties. To display properties, press and hold Ctrl. To toggle back to comments, release Ctrl. The following example illustrates:

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The Named Schemas and Constants section of the Definitions tab lists named schemas defined for the current EventFlow module. Named schemas can be used by any component in the current module that takes a schema. See Using Named Schemas in the Authoring Guide for further information.

The tree view in the Named Schemas and Constants section distinguishes between named schemas defined in the current module and named schemas imported from another module.

Manage named schemas as follows:

You can compare two named schemas in the Named Schemas tab in the same way that you compare the schemas of two components in the canvas. Comparing schemas is best used on closely related schemas, such as an old and new version of the same schema. Use the following steps:

See an example of the Compare Schemas dialog in Compare Schemas above.

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You can define constants with module scope that can thereafter be referenced in any expression in any component or adapter in the containing module. Designate the value of a constant with an expression, which is calculated once when the container holding the module is loaded into the server. See Using Constants for more on constants, including examples.

The tree view in the Named Schemas and Constants section distinguishes between constants defined in the current module and constants imported from another module.

Manage constants as follows:

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Use the Manage Module Imports section of the Definitions tab to import all or a selection of the named schemas and constants from another module to the current module. The modules from which you can import must be in the current module's Module Search Path.

Before using this feature, add the modules of interest to the current module's search path by setting the project properties for the current module. That is, select the current module's project folder in the Package Explorer, right-click and select Properties from the context menu. Then select Project References and select the project folders of interest.

For large, multi-module applications, this feature allows you to define commonly used schemas and constants in a central module, and import them from the central module as needed by other modules in the application.

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