Formula fields

Formula fields are calculated from DBFields, other formulas, summaries, and parameters, so they can present information that DBFields cannot do.

Inserting a formula field in a report

A formula field can be inserted in the report areas listed in Component placement. Before you can insert a formula field into a report, you need to define it. For details about how to define formulas, see Creating a formula.

To insert a formula field into a report, you can use either of the following two ways:

When a formula field has been inserted into a report, you can customize its appearance and behavior by setting properties in the Report Inspector, which can be saved as a CSS style for future use (for details, see Creating a CSS style).

Notes:

Changing the display type of a formula field

The display type of a formula field can be changed, that is to say, you can map the formula field to another value or image to be displayed instead.

To change the display type a formula field:

  1. Right-click the formula field and select Display Type from the shortcut menu.
  2. In the Display Type dialog, specify the required display type in the Type box, and set the options for the selected type in the Web Options panel.
  3. Upon finishing, click the OK button to close the dialog.

For details about display types, see Changing the display type of a label.

Binding a link to a formula field

You can make a formula field linked with another report, a location specified by a URL or an e-mail address. The link can either be a simple link or a conditional link. With conditional link, different targets can be loaded based on different conditions.

To bind a link to a formula field:

  1. Right-click the formula field and click Link on the shortcut menu.
  2. In the Insert Link dialog, specify whether it is a conditional link or a simple link, then select the link target and set the options for the link target as required.
  3. When done, click OK.

For details about different link targets, see Binding a link to a label.

Adding conditional formats to a formula field

You can add some conditional formats to a formula field, then when a specified condition is fulfilled, the format bound with the condition will be applied to the field values automatically for distinguishing.

To add conditional formats to a formula field:

  1. Right-click the formula field and select Conditional Formatting from the shortcut menu.
  2. In the Conditional Formatting dialog, click the button to add a condition.
  3. Set the format that will be applied to the field values when the specified condition is fulfilled.
  4. Repeat the above two steps to add more conditions and define the format for each condition.
  5. When done, click OK to save the settings.

For more details about conditional formatting, see Adding conditional formats to a DBField.

See an example: The SampleComponents catalog, included with JReport Designer, contains reports that have examples of how each component type could be used in a report. For the formula field example, open <install_root>\Demo\Reports\SampleComponents\UsingFormula.cls.