Global View Model Parameters

Global parameters let you provide input to a view model at runtime. They’re available to all the operators in the view model.

Some view models obtain all necessary input from database operations, data services, and other input sources. However, you’ll often want to provide input to your model at runtime that affects the way it functions. For example, a model that processes sales figures might require a parameter specifying the sales region or the fiscal quarter you’re interested in.

Parameters to the view model are called global parameters because they are available to all of the operators and other elements within the model. WorkSpace Data Federation provides tools that let you display, add, modify, and delete global parameters.

If an input source to the view model has parameters, you must map them to global view model parameters.

The view model parameters you define for your model can be referenced in the form variables.global.<globalName>. You can use the Expressions menu to insert references to global parameters into the expressions in your view model’s operators.

The order in which parameters appear in the View Model Parameters tab is the same order in which they appear to calling applications.

Note: If an operator name or a parameter name changes, WorkSpace Data Federation propagates the change to all expressions in the view model that use the changed element. However, this propagation does not apply to the code inside Custom operators, nor does it apply to operator control variables.