EventFlow Editor

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. Most of these commands are available in multiple places: a StreamBase Studio menu, in the right-click context menu, or a toolbar button.

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
Undo Edit	Reverse changes to the last edited component.	Yes	Edit	No
Create Group	Creates a group containing the select components. See Groups.	Yes	No	No
Center Selection	Moves the selection to the center of the canvas.	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.	Yes	Diagram
Zoom Out	Decrements the zoom factor of the entire EventFlow, making details smaller.	Yes	Diagram
Zoom to Fit	Zooms the entire EventFlow in or out to fit within the EventFlow Editor.	No	Diagram
View Source	Displays the View Source window. If you have selected a single component, the window contains the sbapp XML source code for that component only; if you selected zero or multiple components, the entire application is shown. To hide GUI-related code (which has no functional effect) in the View Source window, enable the option, Filter non-semantic elements.	Yes	Diagram	No
Quick Outline	Displays the whole application's components and details in a Quick Outline window. See Quick Outline.	Yes	Diagram	No
Open in Properties View	If a single component is selected, opens its Properties view.	Yes	No	No
Save Schema	If a stream is selected, opens the Save Schema dialog. See Using Saved Schemas.	Yes	No	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	Diagram	No
Layout Application	Rearranges the EventFlow's components and connections.	No	Diagram
Reroute Connections	Rearranges the EventFlow's connections around components.	No	Diagram
Typecheck	Typechecks the selected components in the EventFlow Editor, or the entire EventFlow (if no components are selected).	No	Diagram
[a] The StreamBase toolbar is described in Toolbar Reference.

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Each component in the Editor tab has an associated Properties view, where you can define its properties. 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.

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:

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.

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:

You can group collections of components on your canvas. Groups are a visual tool that can help you edit more efficiently, but they do not affect the functionality of your application. To create a group:

When you first create a group or select an existing group, its Properties view opens. You can define a name, set the background color, and add a description for the group.

You can select the components inside a group independently of the group. Select the group itself by clicking its title bar or any non-component space inside the group.

Here are some useful things you can do with groups:

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.

The text you place in Notes is saved with the EventFlow application, but does not affect the functionality of your application. Note text can be seen as one or more gui.note elements when you view your EventFlow application in text form.

A Note's text can be seen in the Note's tooltip, when you hover the mouse pointer over the Note. You can also select a Note's icon and view the text in the Note's Properties view.

To add a Note:

You can use the following HTML tags in your Note text: b, p, br.

When you delete a component that has an attached Note, the Note remains on the canvas and becomes a free-standing note.

Also see Using Notes.

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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.