Adding an Input Stream or Window to a Project

Input streams and windows accept data from a source external to the project.

You can create an input stream or window by adding an adapter that supports schema discovery, and generating the stream or window to inherit the schema of the external data source automatically. You can then add columns as needed, and specify if they need an autogenerate clause. If an autogenerate clause is added, it can be used to automatically generate data for specified columns.

In the Visual editor workspace, in the Palette menu under the Streams and Windows category, select either:
- Input Stream
- Input Window
Select a location in the diagram and click to add the shape.
To set the name of the input stream or window, either:
- Click to edit the shape name, or,
- In verbose mode, click the Edit icon next to the name.
  
  Note: When you create a duplicate named window or stream in the Vistual Editor, then save your file and switch to the Text Editor, a third duplicate of the original stream or window is created. You can see this third duplicate only when you switch back to the Visual Editor. To remove this third duplicate in the Visual Editor, click Remove all shapes from diagram to clear out all the shapes, then click Add all shapes to get the original stream or window and the second duplicate stream or window back.
Click Add Column to add each new column to the schema, then set key columns and edit column expressions.
To delete columns, select them and press Delete.
(Optional for windows, not permitted for streams) Select Set Keep Policy and choose an option.
(Optional) Double-click the policy to edit its parameters.
(Optional for both windows and streams) Select Set Autogenerate , choose the columns from the Candidate list (only columns with a datatype of Long will populate the Candidate list) and click Add.

Note: You can also manually specify a column you want to add to the autogenerate list by clicking Add Column and entering in a column name. Only columns with a datatype of Long can be used.
To remove columns from the autogenerate list, select them and click Remove.
To set a From value for the autogenerate clause to start with, click Select and choose a variable or parameter from the list. You can also manually enter a variable or parameter that is used within a declare block of a column with a datatype of Long.
Click OK when finished.