Subreport question

[2002 JI Open Discussion]

By: Ulf Heyder - olpp

Subreport question

2003-01-13 08:34

I have a problem with my subreport.

 

The datasource for the mainreport has the fields KEY and NAME.

The datasource for the subreport has the fields KEY and INFO and

is passed to it by the main report through a parameter tag:

 

<parameter name="subDataSource" class="dori.jasper.engine.JRDataSource"/>

...

<dataSourceExpression>

$P{subDataSource}

</dataSourceExpression>

 

My problem now is, that the result looks like

 

------------------------

key1 name1

info11

info12

info21

info22

info31

key2 name2

key3 name3

------------------------

 

instead of

 

------------------------

key1 name1

info11

info12

key2 name2

info21

info22

key3 name3

info31

------------------------

 

I don't know, how I can tell the subreport to print only the

infos wich belong to the corresponding key.

 

The examples only show how to make it with where-clauses in

queries.

 

Can I pass a fieldname to the subreport to filter the

sub-datasource?

 

Any help?

 

Please see the excerpts of the report files below. I can also send the files

per email.

 

Thanks, Ulf

 

 

----------------- begin excerpt mainreport.xml ---------------------------------

<parameter name="subDataSource" class="dori.jasper.engine.JRDataSource"/>

<field name="NAME" class="java.lang.String"/>

<field name="KEY" class="java.lang.String"/>

<detail>

<band height="32">

<textField isStretchWithOverflow="true">

<reportElement x="0" y="0" width="55"

 

height="13"/>

<textFieldExpression class="java.lang.String">

$F{KEY}

</textFieldExpression>

</textField>

<textField isBlankWhenNull="true">

<reportElement x="55" y="0" width="500"

 

height="13"/>

<textFieldExpression class="java.lang.String">

$F{NAME}

</textFieldExpression>

</textField>

<subreport isUsingCache="true">

<reportElement x="5" y="15" width="325"

 

height="15" isPrintRepeatedValues="false" isPrintWhenDetailOverflows="false"

 

isRemoveLineWhenBlank="true"/>

<subreportParameter name="KEY">

<subreportParameterExpression>

$F{KEY}

</subreportParameterExpression>

</subreportParameter>

<dataSourceExpression>

$P{subDataSource}

</dataSourceExpression>

<subreportExpression class="java.lang.String">

 

 

"X:/Privat/UHeyder/Java/Jasper/ListeGemarkungenSub.jasper"

</subreportExpression>

</subreport>

</band>

</detail>

----------------- end excerpt mainreport.xml -----------------------------------

 

----------------- begin excerpt subreport.xml ----------------------------------

<parameter name="KEY" class="java.lang.String"/>

<field name="INFO" class="java.lang.String"/>

<detail>

<band height="11">

<textField isStretchWithOverflow="true">

<reportElement x="10" y="0" width="535"

 

height="11"/>

<textFieldExpression class="java.lang.String">

"Sub: "+$F{INFO}

</textFieldExpression>

</textField>

</band>

</detail>

----------------- end excerpt subreport.xml ------------------------------------

 

 

 

 

 

By: Glenn Owen - grubincan

RE: Subreport question

2003-01-22 06:10

You need to filter the data in your sub report's datasource based on the data in the master row.

 

So your subreport dataSourceExpression needs to look something like...

 

<dataSourceExpression>

((YourDataSourceClass)$P{subDataSource}).filter($F{KEY})

</dataSourceExpression>

 

the filter() method in your subdatasource class needs to:

-filter the data in the datasource (using the passed key value)

- reset the internal row pointer to row 0, so subsequent calls to next() and getFieldValue() return the filtered data.

- return a reference to itself (since that's what the dataSourceExpression is expecting).

 

You can then also remove the KEY parameter for the subreport since the master is managing the filtering.

 

Note: I haven't tried this in XML form, I use the API interface, but it should work correctly.

 

 

 

 

By: Teodor Danciu - teodord

RE: Subreport question

2003-01-22 08:54

 

Hi,

 

I think you have more like an "order" problem

then a "filter" problem.

The data source has to deal with records order

because the reporting engine does not do it.

 

There are proposed sortable data source

implementations, but they are not yet part of

the main distribution.

Since you have already implemented a custom

data source, it is there that you have to deal with

the order.

 

I hope this helps.

Teodor

 

 

 

 

 

By: Stephen Ho - sfgear

RE: Subreport question

2003-06-10 10:01

Hi:

 

I wonder if you can help me out regarding using DataSource in subreport.

 

I wonder how to create a DataSource for the subreport, for the main report I had used the JRResultSetDataSource.

 

Thanks

Stephen