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:

Date-time

Lists all the datetime type special fields.

Print Date
Prints today's date (or the current date from your computer).
Print Time
Prints the current time from your computer.
Fetch Date
Prints the date when the data is retrieved from the database.
Fetch Time
Prints the time when the data is retrieved from the database.
Modified Date
Prints the last modified date of the catalog.
Modified Time
Prints the last modified time of the catalog.

Computed

Lists all the special fields that are computed based on the report.

Record Number
Prints the record number (usually placed in the Details panel).
Group Name
Prints the group name (usually placed in the Group Header/Footer panel).
Total Records
Prints the total number of records after all the filter conditions are performed, except the ones created in the Filter dialog of Page Report Studio, and the Group Filter dialog and top N or bottom N condition in JReport Designer.
Total Fetched Records
Prints the total number of records which take part in grouping calculation. The possible result of the special field is as follows:
- If you don't set any filter condition in the Filter dialog of Page Report Studio, print the very number of the record obtained after setting the property Maximum Records.
- If you set filter conditions in the Filter dialog of Page Report Studio, print the number of records obtained after performing the filters, even though you have set the property Maximum Records before setting the filters.
Group Number
Prints the group number (usually placed in the Group Header/Footer panel).
Total Group Number
Prints the total group number (usually placed in the Group Header/Footer panel).
Page Number
Prints the page number of the report which it is placed in.
Global Page Number
Prints the global page number of the whole report wherever it is placed.
Total Page Number
Prints the total page number of the report which it is placed in.
Global Total Page Number
Prints the global total page number of the whole report wherever the field is placed.
Page N of M
Prints a specific page number out of the total page number of the report which the field is placed in. You can specify the format of this special field. To do this, select this special field, then in the Report Inspector, find the Format property and choose an item from the shortcut list. Besides the items listed here, you can also customize the format. For example, if you want it displayed as "This is page n of m pages", you can input the format string "This is page @PageNumber of @TotalPageNumber pages" into the Format text box.
Global Page N of M
Prints a specific global page number out of the global total page number. You can specify the format of this special field in the Report Inspector. The operation is the same as Page N of M.
SQL Statement
Prints the SQL statements used to execute the query.

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:

In V7 and prior, the Page Number, Total Page Number and Page N of M which are placed in a subreport will calculate the page number of the subreport if the value of the property Embed in a subreport is set to true. And if you set Embed to false, the Page Number, Total Page Number and Page N of M will work as global special fields, it will calculate the page number of the primary report.
While in V8 and after, the Page Number, Total Page Number and Page N of M which are placed in a subreport will calculate the page number of the subreport no matter you set the property Embed to true or fals

System

Lists all the special fields which get values from the system.

User Name
Prints the User ID. When viewing the report in JReport Designer, it returns the name specified for the User Name option in the General category of the Options dialog, while when running the report on JReport Server, it returns the name used to log onto the server. The User Name special field can be used in different data sources as follows:

	Filter Condition	HDS (General)	HDS (XML)	UDS	SQL File	JSON
User Name	Supported.	Supported in the Parameter box in the Add General Hierarchical Data Source dialog.	Supported.	Supported in the Parameter box in the Add User Defined Data Source dialog.	Supported in the SQL statement.	Supported in the Instance box in the Extract JSON Schema screen of the JSON Connection Wizard and the Value column of the HTTP headers and HTTP body in the RESTful Data Source Options dialog.
User Name used in a formula	Supported.	Supported.	Supported.	Supported.	Supported.	Supported.

It should be used as username in formulas and stored procedures and as @username in UDS, imported SQL, JSON and filter conditions.

Task ID
Prints the internal task ID (a unique time stamp). This special field only works in the JReport Server environment. It returns a NULL value when running in JReport Designer.
Report Path on Server
Prints the full path of the report on the JReport Server resource tree. If the report is not running on JReport Server, it returns the full disk path of the report. It returns a NULL value if the report is unsaved.
Report Path on Disk
Prints the full disk path of the report. It returns a NULL value if the report is unsaved.
Catalog Path on Server
Prints the full path of the report's catalog on the JReport Server resource tree. If the report is not running on JReport Server, it returns the full disk path of the catalog. It returns a NULL value if the report is unsaved.
Catalog Path on Disk
Prints the full disk path of the report's catalog. It returns a NULL value if the report is unsaved.

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, Print Date, Print 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, 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:

Position the mouse pointer at the destination where the special field is to be inserted.
Do one of the following:
- Click Insert > Special Fields, and click the corresponding command on the submenu.
- Click the down arrow on the Insert Special Field button on the Insert toolbar and select the required special field from the drop-down list.
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:

Right-click the special field and select Display Type from the shortcut menu.
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.
Upon finishing, click the OK button to close the dialog.

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

Applying web actions to a special field

A special field can be bound with some web actions. This allows you to customize a special field to make it respond to some events, and execute corresponding actions, such as sorting and filtering.

To apply web actions to a special field:

Right-click the special field and select Display Type from the shortcut menu.
In the Web Behaviors box of the Display Type dialog, choose an event from the Events column, then click in the Actions column and click that appears in the text box.
In the Web Action List dialog, select a web action and define the action as required.
Click in the Display Type dialog to add more web behavior lines and specify the events and actions accordingly. If a web behavior is not required, click to remove it.
Adjust the order of the added web actions by clicking or . Then, when an event that has been bound with more than one action happens, the upper action will be triggered first.
When done , click OK to accept the settings.

For more information about web actions, see Applying web actions to 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, an e-mail address, or a Blob data type field. 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:

Right-click the special field and click Link on the shortcut menu.
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.
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:

Right-click the special field and select Conditional Formatting from the shortcut menu.
In the Conditional Formatting dialog, click the button to add a condition.
Set the format that will be applied to the field values when the specified condition is fulfilled.
Repeat the above two steps to add more conditions and define the format for each condition.
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.