Formula Fields

Inserting formula fields in a report

Changing the display type of formula fields

Binding links to formula fields

Adding conditional formats to formula fields

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

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.

Inserting formula fields in a report

Formula fields can be inserted in the report areas listed in Component placement.

For a business view based report
Select the formula from the Dynamic Resources > Formulas node in the Data panel and drag it to the destination.
For a query based report
You have two ways to insert a formula into a query based report.
- By dragging and dropping
  Select the formula from the Formulas node in the Data panel, then drag it to the destination. If the given formulas are not what you want, click the <New Formula...> item to create one as required.
- Using dialog
  1. Position the mouse pointer at the destination where you want to insert the formula and click Insert > Formula or Home > Insert > Formula.
    The Insert Fields dialog appears.
  2. Select the required formula from the Formulas node, then specify its layout in the Insert Layout box.
  3. Click the Insert button to insert the formula into the destination.

Notes:

In a query based report, not all formulas in the catalog are valid in the current context, so under the Formulas node in the Insert Fields dialog or the Data panel, only the valid formulas that are based on DBFields from the current dataset are listed.
If you insert a formula into the detail panel of a data component, the name of the formula will automatically be inserted as a label into the corresponding header panel. Otherwise the formula and its name label will be placed in the same panel. If you do not want to insert the name label automatically, you can uncheck Insert field name label with field in the Options dialog (File > Options > Component > Insert field name label with field).

Changing the display type of formula fields

JReport Designer provides 13 kinds of display types: Text, Image, Barcode, Rank, Text Field, Hidden Field, Text Area, Checkbox, Radio Button, Image Button, Button, List, and Drop-down List. By changing the display type of a formula field, you can map the formula field to other value or image to be displayed instead.

A formula field in a page report created using query resources can be displayed as one of the following general types: Text, Image, Barcode and Rank. It can also be displayed as a basic web control, including Text Field, Password, Text Area, Checkbox, Radio Button, Image Button, and Button. While the formula fields in a web report or library component can only be displayed as Text.

The Display Type feature is not supported in page reports created using business views.

To edit the display type of a formula field:

Right-click it and click Display Type on the shortcut menu.
In the Display Type dialog, select the display type you want the formula field to display in.
If a general display type is selected, take the same procedure as Changing the Display Type of Labels to customize the formula field.
If a basic web control type is selected, see Inserting basic web controls in a page report for details about how to make settings of the display type.
Click OK to accept the changes.

Binding links to formula fields

You can make the formula fields in a report link with other reports, locations specified by URLs, e-mail addresses, or Blob data type fields. The links can either be simple links or conditional links. With conditional links, different targets can be loaded based on different conditions.

To bind a link to a formula field, right-click it and click Link on the shortcut menu, then take the same procedure as described in Binding Links to Labels.

Adding conditional formats to formula fields

You can add conditional formats to formula fields in a report, then when a specified condition is fulfilled, the format defined on the condition will be applied to the field values automatically. This is very useful to highlight values that might need to be acted on by end users.

To add conditional format to a formula field, right-click it and select Conditional Formatting from the shortcut menu, then take the same procedure as described in Adding Conditional Formats to DBFields.

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