Solution

Create a new BaseEnum, let’s call it ProjCust, with the different sorting and/or grouping possibilities, for example one to group by ProjId and one to group by CustAccount.

Create the report Class.

Define in the classDeclaration a DialogField and variable to handle the different sorting/grouping possibilities for the report.

public class TutorialGroupReport_GroupReport 
                       extends RunBaseReport  
{
    DialogField             dialogReportBy;

    ADUProjCustDlvDate      reportBy;     
    #localmacro.CurrentList

        reportBy

    #endmacro
}

In the dialog method, the possibilities to sort/group the report data is shown.

public Object dialog()

{

    DialogRunbase dialog = super();

    ;

    dialog.addGroup("@SYS1046");

    dialogReportBy  = 
      dialog.addFieldValue(TypeId(ProjCust), 
                                   reportBy, 
                                "@SYS55014");

    return dialog; 

}
 

In the getFromDialog method, store the sorting/grouping option chosen by the end user

public boolean getFromDialog()  
{ 

    ;
    reportBy    = dialogReportBy.value();
     return super ();  
}

Create a method to return the option chosen by the end user.

ProjCust reportBy()  
{  
    return reportBy;   
}
 

Create an updateQuery method, which will adapt dynamically the report Query based on the option chosen by the end user

public Query updateQuery()  
{ 

    Query                   query;   
    QueryBuildDataSource    queryBuildDataSource; 

    QueryBuildRange         queryBuildRange;   
    ;
    query = queryRun.query(); 
  
    queryBuildDataSource = 
             query.dataSourceTable(tableNum(ProjTable));
     switch (this.reportBy())   
    { 

        case ProjCust::ProjId:   
            queryBuildDataSource.addSortField(
                            fieldNum(ProjTable,ProjId)); 

            break;   
        case ProjCust::CustAccount: 

            queryBuildDataSource.addSortField(
                       fieldNum(ProjTable,CustAccount));   
            queryBuildDataSource.addSortField(
                            fieldNum(ProjTable,ProjId)); 

            break;   
        default:    // In default, error. 

            throw error(strFmt("@SYS27147", 
                         this.toString()));  
    } 

    return query;   
}

Call the updateQuery method in the run method.

void run()  
{ 

    ;

    this.updateQuery();
     super();   
}

Add the other appropriate methods to the class, such as a lastValueElementName, pack, unpack, description and main method.

Create the Report and the Design of it.

Add your report Class and the report DataSource to be grouped/sorted dynamically as variable the classDeclaration

public class ReportRun extends ObjectRun  
{ 

    TutorialGroupReport_GroupReport tutorial_GroupReport;   
    ProjTable                       projTable; 

}

Assign the caller to the report Class variable in the init method.

public void init()   
{
    super();
     tutorial_GroupReport = element.args().caller(); 

}

In the fetch method you can change the sorting/grouping dynamically based on the choice of the end user and if necessary add additional design stuff.

public boolean fetch() 

{   
    QueryRun        queryRunProjTable; 

    ProjId          parentProjId;   
    CustAccount     custAccount; 

    ;
    queryRunProjTable = new QueryRun(
                tutorial_GroupReport.updateQuery()); 
  
    this.queryRun(queryRunProjTable);

    while (queryRunProjTable.next()) 

    {   
        projTable = queryRunProjTable.get(
                               tableNum(ProjTable)); 


        switch (tutorial_GroupReport.reportBy())   
        { 

            case ProjCust::ProjId:   
                if (projTable.ParentId != parentProjId) 

                    this.execute(1);   
                    parentProjId = projTable.ParentId; 

                break;  
            case ProjCust::CustAccount: 

                if (projTable.CustAccount != custAccount)   
                    this.execute(2); 

                    custAccount = projTable.CustAccount;   
                break; 

            default:    // In default, error.   
                throw error(strFmt("@SYS27147", 
                             this.toString())); 
        } 
  
        this.send(projTable);   
    } 

    return true;   
}