# ScalarParameter

Defines a simple single-value parameter.

### Description

This element defines a single-value parameter. Scalar parameters can have selection lists.

Scalar parameters can provide a selection list. The list can be static (defined by the `selectionList` property) or dynamic (defined by the `dataSet`, `valueExpr` and `labelExpr` properties.) The user can be required to select a value from the list, or can enter a value not in the list (as controlled by the `mustMatch` property).

BIRT uses the following rules to determine the selection list:

- If the dataSet property is set, then the selection list is dynamic.
- Else, if the selectionList property has one or more entries, use that list.
- Else, assume the parameter has no selection list.

### See Also

`selectionList` property

`defaultValue` property

## defaultValue

The default value of the parameter.

### Description

The default value for the parameter. The default value can be an expression, but cannot reference any other parameters.

## concealValue

Hides the user’s entry by displaying asterisks or similar characters. Often used for passwords.

### Description

This property hides the user’s entry by displaying asterisks or similar characters. Often used for passwords. The default is to show the entry in plain text.

### See Also

`hidden` Property

## format

Formatting pattern for showing the parameter in the UI.

### Description

Formatting instructions for the parameter value within the parameter UI. For UIs that are able to show formatted parameter values, provides a BIRT format used to display the value. The format is dropped, and the unformatted value presented, when the user edits the parameter value.

Formatting instructions for the parameter value within the parameter UI. By default the UI should use the following rules:

- Text ? No formatting.
- Number, Float, Date-Time ? Default locale formatting.

The format string must be one of the valid BIRT format strings (see the Style element for a list.) The format is used by the UI to display the value after the user moves away from a field. For example, to format a number as a dollar amount.

### See Also

## controlType

The suggested type of UI control to use when displaying the parameter.

### Choices

- text-box: The user can type in the value.
- list-box: Requires a list of choices: static or dynamic. Shown as a list box if set of choices are fixed, combo-box if set of choices is open.
- radio-button: Only allowed for a fixed set of choices.
- check-box: Only for Boolean values

### Description

The suggested type of UI control to use when displaying the parameter. The default depends on the parameter properties:

- text-box ? Default for non-Boolean values when no choices are available.
- list-box ? Default for parameters with choices.
- check-box ? Default for Boolean values.

The list-box control is rendered in the UI depending on the value of the `mustMatch` property. If `mustMatch` is true, then the user much choose a value from the list, and the control is rendered as a UI list box. However, if `mustMatch` is false, then the user can chose an item from the list, or type in a different value, and the control is rendered as a UI combo box.

### See Also

`mustMatch` property

## alignment

How the items should appear in the UI. Choices are auto (default), left, center or right.

### Choices

- auto: Numbers are left aligned, all others are right aligned.
- left: Values are left-aligned.
- center: Values are centered.
- right: Values are right-aligned.

### Description

How the items should appear in the UI. Choices are auto (default), left, center or right.

### See Also

`mustMatch` property

`fixedOrder` property

`controlType` property

## mustMatch

If true, then the value that the user provides must match one of the values in the static or dynamic selection list.

### Description

If true, then the value that the user provides must match one of the values in the list. If false, then the values in the list are a reference; the use can enter additional values as well. Ignored if the property does not have a selection list.

### See Also

## fixedOrder

Whether to display the list sorted in unsorted (fixed) order.

### Description

Whether to display the values in the order defined in the list, or whether to resort the list lexicographically based on the actual translated values. The default is true, and the selections are displayed in the order in which they are defined.

### See Also

`selectionList` property

`dynamicList` property

This element defines or references a query that defines a dynamic selection list for the parameter. The data set can reference other parameters, but only those that appear in the design before this parameter. Sorting can be done by the data set (if the fixedOrder property is true), or can be done by BIRT (if the fixedOrder property is false.)

The data set must return a column that contains the choice values. It may also contain a column that returns the labels for the values. All other columns are ignored. The choice is that passed to the report when run. The optional display value is shown to the user in the UI. For example, the display values might be “Residential?, “Commercial?, and “Government? while the corresponding parameter values are “R?, “C?, and “G?.

### See Also

## boundDataColumns

Bindings the data set column and expressions with the property values..

### Description

Property values of a scalar parameter can bind to a data set column through bound data columns' names. If a data set column or expression are not bound in the data columns, the exeuction of the expression fails.

### See Also