Using the Report Viewer

Overview
Viewer Operations
Run a Report
Viewer Frameset
Viewer Command Options
Report Parameters
Error Reporting

Overview

The Viewer performs three distinct operations, of which one is internal and not visible to your application:

Create a frameset-based viewer that interacts with the servlet using AJAX to support more features.
Given a set of report parameter values, run a report and return the output as either HTML or PDF.
Retrieve an embedded image, or an image of a chart within the report (internal operation).

You can use a full-feature viewer frameset that handles parameter entry, Table of Contents, export to CSV and HTML pagination. Or, you can supply the parameter values and simply run the report to produce a simple HTML or PDF output page.

Viewer Operations

The Report Viewer provides a number of URLs that control its behavior. The Report Viewer provides two modes of operation as given by two servlet mappings.

Operation	Description
frameset	Displays a frameset that contains the report and additional AJAX components for retrieving Table of Contents, exporting to CSV, parameter entry and paging controls.
run	Runs the report and displays the output as a stand-alone HTML page, or as a PDF document.

The servlet mapping names are case-sensitive.

Run a Report

The run servlet mapping runs a report given a set of report parameters, and returns the report as an HTML page or PDF document. This servlet mapping does not provide a frameset. Use this option if you want the report to appear as a stand-alone page or if PDF output is required. Parameters must be handled in one of three ways:

The report requires no report parameters.
Your application already knows the values of the parameters (perhaps from a server session), and passes them along.
Your application has created a parameter page specifically for the report.

Birt 2.2 or Later Runtime Note:

If your report has a required parameter with no default value, the parameter entry screen will be displayed automatically.

The run report URL is of the form:

http://sitePrefix/birt-viewer/run?option1=value1;option2=value2;...

See below for a list of available viewer command options.

Viewer Frameset

The frameset command provides additional UI to work with a report. Use this URL if your report contains parameters, and you want the viewer to display a UI so the user can enter parameter values. Using the frameset command also allows for HTML pagination.

The frame-based viewer displays a frameset that contains the report and controls for the following functions:

Table of Contents - use this navigate report. Selecting a link in a multi-page report will automatically load the desired page.
Run Report - use this control to enter parameters and execute the report.
Export Data - this control prompts the user to select what report data should be exported to CSV.
Page Controls - navigate paginated HTML report output.

The parameters dialog displays a form for entering the parameters (if any) for a report. It contains a Run Report button that runs the report. The report then appears in the report frame. The user can refine the report simply by modifying parameters in the parameter frame and again by clicking on Run Report.

The viewer URL is of the form:

http://sitePrefix/birt-viewer/frameset?option1=value1;option2=value2;...

See below for a list of available command options. The command options allow you to control which of the three frames appear in the resulting Web page.

When you issue this command, the viewer will do one of two things:

Run and display the report if any of the following conditions are true.
- The report has no parameters
- All parameters have supplied default values.
- All parameters have allowNull property checked
Display the parameter page and ask you to enter parameters. You can then click the Run Report button to run the report.

Viewer Command Options

The run and the frameset viewer operations both take a set of options which include report parameters. Report parameters are defined within the report design. They appear in the URL using their internal names, not display names. Viewer options pass information to the Report Viewer Web application. Viewer options start with a double underscore to differentiate them from report parameters. Option names and values must be encoded for use in a URL. For example:

http://localhost:8080/carnot-reporting/run?__report=report%5CSalesInvoice.rptdesign&OrderNumber=10010

In the above:

http://localhost:8080/ � the URL (including port) for your installation of the application server
/carnot-reporting/ - the context name of the Web application
run - the servlet mapping for running a report
report%5CSalesInvoice.rptdesign � relative file system path of the report to run. The name is relative to the Web app directory in which the Birt viewer was installed.
OrderNumber=10010 � the name and value of a report parameter as defined in the report design

List of Options

The available viewer options include:

Option	Description	Values	Default	frameset	run
`__format`	The output format	html or pdf	html	N	Y
`__isnull`	Identifies that a report parameter has a null value	Parameter name	None. Required.	N	Y
`__locale`	Report locale	Java locale value such as en, en-us or ch-zh.	JVM locale	Y	Y
`__report`	The path to the report design.		None. Required.	Y	Y
`__document`	The path to the report document.		None. Required.	Y	N
`reportParam`	Report parameter.	As specified in the report design.	As specified in the report design.	Y	Y

Case-Sensitivity

Case-sensitivity of the options varies:

Viewer option names and values are case-insensitive.
Report parameter names are case-sensitive: they must match the name as defined in the design.
The file name case sensitivity is defined by your operating system.

If the URL contains a misspelled option name, or the names of report parameters are in the wrong case, then the viewer silently ignores the parameter.

The __format Option

The type of output to produce: either HTML or PDF. Values are case-insensitive. If a value other than PDF is provided, the HTML format is produced.

The __isnull Option

Report parameters can take a value, or can be null. Hereby, "null" means the database definition: the value is unknown. By definition, date and numeric report parameters have a null value if the report parameter is provided in the URL, and the value is blank. However, string report parameters have an ambiguity: is an empty value to be considered blank (a string whose value is ""), or null? Since blank is used more often, the Business Analysis and Reporting Component interprets an empty report parameter value as blank.

To say a string parameter is null, just write:

__isnull=yourParam

While this option is primarily for string report parameters, it works just as well for other report parameter types as well. See the Report Parameters section below for additional details.

The __locale Option

Use the __locale option to specify both the locale for report parameter values, and the locale for the report output. The locale must be a valid Java locale such as en-us , etc. as specified in the Sun Java locale guidelines. If you do not specify a locale, it defaults to the locale set in the Java virtual machine (JVM).

Values are case-insensitive.

The __report Option

The __report option names the report design to run. It can be an absolute or relative file name. If relative, the looks in the directory specified in the BIRT_VIEWER_WORKING_FOLDER property in the viewer's web.xml file. The file search rules are:

If name is absolute, use it directly.
If BIRT_VIEWER_WORKING_FOLDER is set, use this value as the base for the relative name.
Otherwise, use the viewer Web applications directory as the base for the relative name.

The __document Option

The __document option names the report document to run with the frameset mapping. This file is the intermediate file when run and render are separate phases. It can be an absolute or relative file name. If relative, the looks in the directory specified in the BIRT_VIEWER_WORKING_FOLDER property in the viewer's web.xml file. The file search rules are:

If name is absolute, use it directly.
If BIRT_VIEWER_WORKING_FOLDER is set, use this value as the base for the relative name.
Otherwise, use the viewer Web applications directory as the base for the relative name.

Report Parameters

Report parameters can be Boolean, Number, Date, Float or String. The values are defined as follows:

Data Type	Value Encoding	Notes
Boolean	true, false	Must use the value true for a true value, all other values (including 1) are treated as false. (Uses the Java `Boolean.parse()` method for parsing.) Values are case-insensitive.
Number	Floating point number with a locale-specific decimal separator.	Must not include a thousands separator, or extra characters such as a currency symbol. Uses the Java `java.text.DecimalFormat` class to parse the number.
String	None
Date	Locale-specific date format.	Uses the Java `java.text.SimpleDateFormat` class to parse the date.

Report Parameter Value

The rules for a given parameter foo are determined by the first rule below that takes effect:

If __isnull=foo appears in the URL, foo's value is null.
If foo=mumble appears in the URL, foo's value is mumble.
If foo= appears in the URL, foo's value is blank if it is a string, and null if it is a number or date.
If foo has a default value, foo's value is that default value.
Otherwise, foo's value is blank for string or null for number and date.

Value Checking

The report definition provides two properties for report parameters that influence parameter validation. First, the allowNull property determines if a report parameter can be null. If a report parameter has a null value, but the allowNull property is false, then the Stardust Report Engine will raise an error.

Second, string report parameters have a allowBlank property. If the report parameter has a blank value, and allowBlank property is false, the Stardust Report Engine will raise an error.

Error Reporting

If an error occurs during the operation, an error page will appear.