Reading more Subfile records at a time: Usability technique

Estimated reading time: 4 minutes

Source

You can get the GitHub Source Files here.

Overview

The Pages on the Website Project can present to the user only the information available in the DataSet. In order to add more information, the Programs in the Logic Project(s) need modification.

Reading more Subfile records

Page ~\SunFarmSite\Areas\SunFarmViews\Pages\CUSTDSPF.cshtml defines a Subfile Controller Record that uses a Subfile with a page-size of fourteen records.

Starting at Row 6, with a Span of fourteen rows, the definition of the Subfile was migrated as follows:

   @{
      int SFLC_SubfilePage = 14;
   }

    <div Row="6" RowSpan="@SFLC_SubfilePage">

Note how a C# constant is used to specify the RowSpan property.

We could modify SFLC_SubfilePage constant to display more records, for example, to display four more, we can change this constant to:

   @{
      int SFLC_SubfilePage = 14 + 4;
   }

But that would not be enough, as you can see by running the Application with the change.

Even when the display area allocated to the subfile grew, the Controller’s Model does not have any more records in the DataSet.

Assuming we have knowledge regarding how the Logic is implemented, we can identify where the subfile is being written to, and then write more records to it.

The subroutine LoadSfl has a hard-coded value 14 which controls the maximum records written to the subfile.

    BegSr LoadSfl
        SetOff *IN61 //Start with green.
        *IN90 = "1" //Clear the subfile.
        Write SFLC

        SetOff IndList( *IN76, *IN90 ) //Display records.
        sflrrn = 0
        .
        .
        .
    //----------------------------------------------------------

        DoWhile ( *Not *IN77  /* EOF or full s/f. */ +
            *And ( sflrrn < 14 ) )
        .
        .
        .

            sflrrn = sflrrn + 1
            Write SFL1
            .
            .
            .

        EndDo

Instead of increasing the hard coded 14 to a new value, let’s define a constant (since there are two places that refer to this value).

BegClass CUSTINQ Extends(Program) Access(*Public) + 
    .
    .
    .

    DclConst CustomerSufilePageSize 14+5

Now that CustomerSufilePageSize has been defined, we will use it instead of the hard-coded 14.

Compiling the SunFarmLogic project should read more records from the database, loading the subfile, making the new data available in the DataSet, accessible by the UI (Website).

There is one more place we need to update, the Display Page Model.

Let’s add the constant definition CustomerSufilePageSize to the CUSTDSPF class, as follows:

    public class CUSTDSPF : DisplayPageModel
    {
        public const int CustomerSufilePageSize = 14 + 5;

With the new constant, we can change the hard coded controller property SubfileControl.Size:

        [
            SubfileControl(ClearRecords : "90",
                FunctionKeys = "F9 09;PageUp 51:!76;PageDown 50:!77",
                DisplayFields = "!90",
                DisplayRecords = "!90",
                Size = CustomerSufilePageSize,
                IsExpandable = false,
                EraseFormats = "CUSTREC , SALESREC"
            )
        ]

And on the Razor Page, we can use the Model’s public property as follows:

<div Row="5" RowSpan="@CUSTDSPF.CustomerSufilePageSize">
    @for (int rrn=0; rrn < Model.SFLC.SFL1.Count; rrn++)
    {
        .
        .
        .

And we accomplished our goal, instead of fourteen records we can now show nineteen per page (see results below).

Note: we sneaked two smaller changes, first, instead of four more records we are adding five. This is possible because we also started at Row=”5” instead of “6”.

Results

Fourteen Customer per Page	Nineteen Customers per Page