Special fields

Special fields are defined by JReport and allow you to easily obtain system information and report-related data and add it to your report. The special fields are as follows:

Note: Page Number, Total Page Number and Page N of M in the following conditions in versions after V8 are different from those in versions prior to V7:

Referencing special fields in a formula

Some special fields can be used in formulas. They are User Name, Print Date, Print Time, Fetch Date, Fetch Time, Modified Date, Modified Time, Record Number, Page Number, Global Page Number, Total Records and Total Fetched Records. They can all be divided into two types (page level and constant level) according to the time when their values are ready.

Page level

The value of this special field is ready at the time when the report result is generated. A formula which references a page-level special field is treated as a page-level formula. In which, the formula is calculated more than once.

The special fields of this type are: Fetch Date, Fetch Time, Record Number, Page Number, Global Page Number, Total Records and Total Fetched Records.

Constant level

The value of this special field is ready at any time before the engine runs. A formula which references a constant-level special field is treated as a constant-level formula, and is calculated only once.

The special fields of this type are: User Name, Print Date, Print Time, Modified Date and Modified Time.

Inserting a special field into a report

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

To insert a special field into a report:

  1. Position the mouse pointer at the destination where the special field is to be inserted.
  2. Do one of the following:
  3. Click in the destination to insert the special field.

When a special 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).

Changing the display type of a special field

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

To change the display type a special field:

  1. Right-click the special 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 special field

You can make a special 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 special field:

  1. Right-click the special 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 special field

You can add some conditional formats to a special field, then when a specified condition is fulfilled, the format bound with the condition will be applied to the field values automatically for distinguishing. However, conditional formatting applies only to the two special fields: Page Number and User Name.

To add conditional formats to the special field Page Number/User Name:

  1. Right-click the special 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 special field example, open <install_root>\Demo\Reports\SampleComponents\ForSpecialFields.cls.