HOWTO: Perform a Calculation on One Row of a Query

Question

Use this method if you can't perform the calculation at the entity object level--for example, if the calculation involves columns from more than one table, involves transient attributes, or if your view object is pure SQL-based (i.e., not based on any entity objects).
First, you have to generate a view row class.
1. Right-click the view object that represents your query and choose "Edit."
2. When the View Object wizard appears, select the Java page.
3. In the View Row panel, select "Generate Java Class" and "Generate Accessors."
4. Click "Done".
This generates a class called <VoName>RowImpl.java
Next, you should edit the class and add a method that performs your calculation.
1. Double-click the class to bring it up in the source editor.
2. Add a method to perform your calculation, such as the following:
public int sumCol1AndCol2() {
int Col1Val=getCol1().intValue();
int Col2Val=getCol2().intValue();
return (Col1Val + Col2Val);
Next, you need to export your method so that your client can use it.
1. Right-click the view object and choose "Edit."
2. Select "Client Row Methods."
3. In the "Available" list, select the method you just added.
4. Shuttle it to the "Selected" list.
5. Click "Done".
This generates an interface called <VoName>Row containing your method. You should always call <VoName>Row from your client, never <VoName>RowImpl.
Now you're ready to call the method from your client. Here's an example of how you might do it in a JSP client:
<jbo:Row id="myrow" datasource="myVoDataSource" action="Current">
<% out.println( ((myVoRow) myrow).sumCol1AndCol2() ); %>
</jbo:Row>
Note that you have to cast myrow to your interface, since the method you created isn't on the generic interface jbo.Row.
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Answer 1

Use this method if you can't perform the calculation at the entity object level--for example, if the calculation involves columns from more than one table, involves transient attributes, or if your view object is pure SQL-based (i.e., not based on any entity objects).
First, you have to generate a view row class.
1. Right-click the view object that represents your query and choose "Edit."
2. When the View Object wizard appears, select the Java page.
3. In the View Row panel, select "Generate Java Class" and "Generate Accessors."
4. Click "Done".
This generates a class called <VoName>RowImpl.java
Next, you should edit the class and add a method that performs your calculation.
1. Double-click the class to bring it up in the source editor.
2. Add a method to perform your calculation, such as the following:
public int sumCol1AndCol2() {
int Col1Val=getCol1().intValue();
int Col2Val=getCol2().intValue();
return (Col1Val + Col2Val);
Next, you need to export your method so that your client can use it.
1. Right-click the view object and choose "Edit."
2. Select "Client Row Methods."
3. In the "Available" list, select the method you just added.
4. Shuttle it to the "Selected" list.
5. Click "Done".
This generates an interface called <VoName>Row containing your method. You should always call <VoName>Row from your client, never <VoName>RowImpl.
Now you're ready to call the method from your client. Here's an example of how you might do it in a JSP client:
<jbo:Row id="myrow" datasource="myVoDataSource" action="Current">
<% out.println( ((myVoRow) myrow).sumCol1AndCol2() ); %>
</jbo:Row>
Note that you have to cast myrow to your interface, since the method you created isn't on the generic interface jbo.Row.
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