Lesson 17: Jasper Reports (continued)

As a System Admin I want to view a report of purchases made.

Lesson Outcomes

By the end of this lesson you should:

• Know how to include Jasper reports that will be viewed on the front-end
• Understand and know how to use parameters in Jasper reports
• Know how to use custom parameter filters
• Know how to use custom menu items for reports or groups of reports

Modified or Added App Files

./jasper-reports/AllFarmerPurchases/leaf_banner_gray_0.png

./jasper-reports/AllFarmerPurchases/master.jrxml

./jasper-reports/AllFarmerPurchases/report.json

./jasper-reports/FarmerUserPurchases/leaf_banner_gray_0.png

./jasper-reports/FarmerUserPurchases/master.jrxml

./jasper-reports/FarmerUserPurchases/report.json

./utilities/ReportParameterFilters.mez

Creating a Jasper Report for the Purpose of Viewing on the Frontend

To add a report to a Helium application we must first create a folder called jasper-reports in the project root directory. Each report will then have its own subfolder with the jrxml files, images and a Helium specific report.json file. The main report should be named master.jrxml. There is no convention for naming of subreport files or images.

The report.json file will contain the configuration information required by Helium for the specific report. This will include which user has access to the report, which parameters are needed by the report and whether the report will be using its own menu item, a report group menu item or the default menu item for reports. For our first example we will consider the report under the AllFarmerPurchases folder. This report is accessible using the default report menu item. It is accessible for only the "System Admin" role, and does not make use of any parameters. The content of the report.json file is as follows:

{
	"name":"All Farmer Purchases",
	"description":"All farmer purchases system wide",
	"rolesAllowed":["System Admin"]
}

This results in the following menu item and Helium provided view for the "System Admin" role:

Any other reports that also use the default menu item will appear in this table. The default menu item for reports is always ordered to be the last menu item in the menu.

Using the Show button, our report will be displayed along with options to download the report in PDF and EXCEL formats.

Specifying and Using Report Parameters

As a next step we will make a copy of the report for viewing by the "Farmer" role. We will modify the report query to make use of the built-in USER_APP_ROLE_ID parameter provided by Helium. This will limit the purchases shown to those of the current farmer user. Note that the mentioned parameter is provided by Helium and does not need to be mentioned in the report.json file. The updated report query now contains the following where clause:

where farmer._id_ = $P{USER_APP_ROLE_ID}::uuid

The report.json file is as follows:

{
	"name":"Your Purchases",
	"description":"Your purchases",
	"rolesAllowed":["Farmer"]
}

We can now apply further filtering. Filtering criteria can be applied to show only the following purchases:

• Purchases between a start and end date
• Purchases from a specific shop
• Purchases over a certain cost

We modify our report.json file as follows:

{
	"name":"Your Purchases",
	"description":"Your purchases",
	"rolesAllowed":["Farmer"],
	"parameters":[
		{
			"parameterName":"startDate",
			"displayName":"Start date",
			"type":"date"
		},
		{
			"parameterName":"endDate",
			"displayName":"End date",
			"type":"date"
		},
		{
			"parameterName":"shopId",
			"displayName":"Shop",
			"type":"uuid",
			"searchType":"Shop.name"
		},
		{
			"parameterName":"minCost",
			"displayName":"Minimum purchase cost",
			"type":"string"
		}
	]
}

Note how we used a string type for the minCost parameter. Helium supports the following paramater types:

• boolean
• date
• datetime
• string
• uuid

Any parameter that is of a different type, can be captured as a string.

Also note that for each parameter added to the report.json file, a parameter should also be added to the Jasper report. Failure to do so will result in the report not compiling:

|--------------------------------------------------------------------------------------------------|
| The Jasper reports for the project "helium-tut" failed to compile with the following errors      |
|--------------------------------------------------------------------------------------------------|
| #     | Message                                                                                  |
|--------------------------------------------------------------------------------------------------|
| 1     | [Your Purchases] The master.jrxml file doesn't declare a "shopId" parameter              |
| 2     | [Your Purchases] The master.jrxml file doesn't declare a "endDate" parameter             |
| 3     | [Your Purchases] The master.jrxml file doesn't declare a "minCost" parameter             |
| 4     | [Your Purchases] The master.jrxml file doesn't declare a "startDate" parameter           |
|--------------------------------------------------------------------------------------------------|
The last command completed in 0.22 seconds

Even though we have specified a uuid type for the shopId parameter in the report.json file, this is mostly for Helium to provide an appropriate input widget and does not represent the type of the parameter that is received by the Jasper report. In this case the type of the parameter on the Jasper Report side can be specified as java.lang.String and cast to a uuid in the report query as appropriate.

<parameter name="shopId" class="java.lang.String">
	<parameterDescription><![CDATA[]]></parameterDescription>
	<defaultValueExpression><![CDATA[""]]></defaultValueExpression>
</parameter>

With the parameters added to our report.json file and the report modified accordingly, we will see the following view when selecting our report on the frontend before displaying the actual report:

Custom Filters For Parameters

In the above example users must select a start and end date and shop. The list of shops to select from is, however, not influenced by the values of the start and end date. In order to filter the shops listed using the start and end dates a special Helium report parameter filtering mechanism must be used. To make use of this we will create a new Unit called ReportParameterFilters under the utilities folder of our project. Here we specify what should happen when the start and end dates are selected and which shops should be provided to select from:

unit ReportParameterFilters;
date startDate;
date endDate;
 
// Called when the start date is selected from the report parameter view
void setStartDate(date startDateParam) {
	startDate = startDateParam;
}
 
// Called when the end date is selected from the report parameter view
void setEndDate(date endDateParam) {
	endDate = endDateParam;
}
 
// Used as a collection source from which the shop report parameter can be selected
Shop[] shopFilter() {
	FarmerPurchase[] purchases = FarmerPurchase:and(
		lessThanOrEqual(purchasedOn, endDate),
		greaterThan(purchasedOn, startDate)
	);
	
	return Shop:relationshipIn(purchases, purchases);
}

To link the app logic to our report parameters make use of the searchDestination and searchSource attributes in our report.json file:

{
	"name":"Your Purchases",
	"description":"Your purchases",
	"rolesAllowed":["Farmer"],
	"parameters":[
		{
			"parameterName":"startDate",
			"displayName":"Start date",
			"type":"date",
			"searchDestination":"ReportParameterFilters:setStartDate"
		},
		{
			"parameterName":"endDate",
			"displayName":"End date",
			"type":"date",
			"searchDestination":"ReportParameterFilters:setEndDate"
		},
		{
			"parameterName":"shopId",
			"displayName":"Shop",
			"type":"uuid",
			"searchType":"Shop.name",
			"searchSource":"ReportParameterFilters:shopFilter"
		},
		{
			"parameterName":"minCost",
			"displayName":"Minimum purchase cost",
			"type":"string"
		}
	]
}

Instead of listing all shops in the system, users will only be presented by shops with purchases between the start and end date parameter values.

Note that when a search destination is specified for a parameter that is of type uuid, it is not the object instance represented by that uuid that is sent to the search destination function as an argument but instead the id of the selected object instance. Consider the example below where the shopId parameter has an accompanying search destination instead of a search source:

{
	"parameterName":"shopId",
	"displayName":"Shop",
	"type":"uuid",
	"searchType":"Shop.name",
	"searchDestination":"ReportParameterFilters:setShopFilter"
}

unit ReportParameterFilters;
uuid selectedShop;
.
.
// Called when the shop is selected from the report parameter view
void setShopFilter(uuid shopId) {
	selectedShop = Shop:read(shopId);
}
.
.

Note the use of the read built-in function. This is used instead of an equals selector and return a single object instance instead of a collection. Although not relevant in this specific use case, a null value will be returned if an id that does not represent an existing shop is used as an argument to the read built-in function above.

Custom Report and Report Group Menu Items

So far we have demonstrated the default reports menu item provided in Helium. Developers also have the option to make reports available from other report specific menu items using the following attributes, as example, in the report.json file:

"menuGroupName":"Purchases Reports",
"menuItemOrder":"0",
"menuItemIconName":"report_icon.png"

Using the above, reports using the same menu group name will be grouped together under a menu item that leads to a view with a table of the specified reports. Each report can then be accessed using Show button on the table. If instead the following is used, a single report can be directly accessed from a menu item:

"menuItemName":"Purchases Report",
"menuItemOrder":"0",
"menuItemIconName":"report_icon.png"

Summary of Fields in report.json

For reference see below a summary of the available attributes that can be specified in a report.json file.

Report Downloads From DSL Code

Helium 1.57 introduces functionality for triggering a report download from DSL code. For more details see Jasper Report Downloads.

Troubleshooting

There are several caveats and complications when using Jasper to create reports or JasperSoft to test and plan reports. Please see the following page for a list of currently described issues or notes: /wiki/spaces/HP/pages/5076209

Lesson Source Code

Lesson 17.zip