Creating Topics

When a user clicks Create > Ad Hoc View on the Home page, the list of Topics on the Topics tab is populated from the Ad Hoc Components/Topics folder in the repository. There are two types of Topics:

JRXML-based Topics – Created by administrators using iReport and uploaded as JRXML files to the proper location in the repository. Topics are typically of this type.
Domain Topics – Created from a Domain by administrators using JasperReports Server.

Either type of Topic is an empty view associated with a data source in the server, and is then built on in the Ad Hoc Editor.

Creating and Uploading a Topic

JRXML-based topics are the most common type of topic. You can upload previously-created JRXML topics via the repository.

To upload a JRXML-based Topic:

1. Log into the server as administrator and select View > Repository.

While any user with sufficient repository permissions can upload a Topic to the server, this example requires an administrator login to access the JServer Jdbc data source.

2. Locate thefolder where Topics are stored. The location of the Topics folder depends on your system configuration; by default, Topics are in the Ad Hoc Components > Topics folder.
3. Right-click the Topics folder and select Add Resource  > JasperReport from the context menu.

Add Resource appears on the context menu only if your login account has write privilege to the folder.

After selecting Add Resource > JasperReport, the Set Up the Report page of the JasperReport wizard appears.

4. In the Set Up the Report page, give the Topic a name, a Resource ID, and an optional description, then click Next.
     The Name field is the visible name of the file in the repository, such as Example Topic.
     The Resource ID field is the internal ID of the object, such as Example_Topic. The server does not accept spaces in an internal ID.
     The Description field, such as Topic uploaded for User Guide example, helps users understand the purpose of the file.
5. In the Locate the JRXML File section, select Upload a Local File, and click Browse to locate the file and upload the Topic from the file system. In this example, the file is <js-install>/samples/adhoc/topics/adhoc_sample.jrxml.

To locate adhoc_sample.jrxml, you need access to the server host file system.

6. Click Data Source.

Because this is a simple Topic without parameters, there are no controls and resources associated with it. If the Topic has a Parametrized query, you can create input controls for it. See Selecting a Data Source for Running the Complex Report. Such input controls can appear in the Ad Hoc Editor and when the report is run.

7. Click Select data source from repository and Browse to locate the data source named Data Sources/JServer Jdbc data source.

Topics must be associated with the data source that they were designed for.

8. Click Next.
9. In Locate Query, click Submit.

Topics usually do not need a query or customization, but you can define them.

When you select Create > Ad Hoc View, the Example Topic appears on the Topics tab of the Data Chooser wizard. If you select the Example Topic, you can create a report using the columns available in the data source selected in step 7.

When you create a JRXML file for use as a Topic, you can specify the name to display for each field that the Topic returns. To do so, define a field property named adhoc.display for each field declared in the JRXML. The adhoc.display field property must have the following syntax:

<property name=”adhoc.display” value=”Any Name”/>

For example, this JRXML code declares a StoreState field that is displayed in reports as Store State:

<field name=”StoreState” class=”java.lang.String”>
 <property name=”adhoc.display” value=”Store State”/>

Topics also support the $R expressions for field names; for more information, see Localizing Reports.

For fields in a non-domain topic the following properties may be of interest:

dimensionOrMeasure: marks a field as a field or a measure
defaultAgg: which aggregation should be used for this measure (avg, etc)
semantic.item.desc: A description for the field
DefaultMask: set a measure as a $, date etc