Ask Dr. DePhobia - Questions and Answers about Clarion

by Jim DeFabia

Published 1999-04-01    Printer-friendly version

Q:

What's new in the Clarion 5A release?

A:

Lots of exciting stuff! While Clarion 5A is primarily a bug fix release, there are several enhancements that enable you to easily add functionality to your applications. Here is a short list:

• The most exciting feature is the Beta 2 release of the Wizatrons. You will find full instructions on using them in the Wizatron Handbook PDF. There are many changes to the Wizatrons.
• Print Preview now has an option to specify Pages to Print (File -> Pages to Print). Yes, you get this in every report which uses Print Preview without changing a thing in your application.
• There are also new properties in the PrintPreviewClass to control this in code. I cover a few of these in another question in this column.
• There is a new EIPManager class and an EditSpinClass.
• The QBE List interface has been implemented. This is described on page 131 of the Application Handbook. (It was documented, but not implemented in prior releases). I cover some of this functionality in another question in this column.
• There are several new classes in the ABC Class Library. These are all documented in the revised Application Handbook PDF file and a separate PDF of the new portions is also provided. This gives you a printable version you can tuck in the back of your Application Handbook.
• An Entry Control with a lookup enabled now has the ability to perform additional field assignments (on the Actions Tab of an Entry control).
• The TopScan database utility now has online help.

Q:

I want to use the built-in QBE feature to limit a list to a range of values, but the Query form only allows a field to be populated once. Is there an easy way to query on a range?

A:

Query, Query on the range, where the deer and the antelope... Sorry, got lost in song for a moment.

So you want to query on a range of values, well Clarion 5A now has the QueryListVisual and QueryListClass with full template support for a list-type query.

Let's look at how this works.

1. On a Browse procedure, populate a BrowseQBEButton control template.
2. Right-click on the BrowseQBEButton and select Actions.

3. Press the QBE Options button.This allows you to set the options for the QBE process.

4. Choose List from the drop-list of QBE interface choices.

Next, you would either check the Auto-populate box, or Press the Fields button to select the fields to populate. For the purpose of this article, let's assume that you only want to enable QBE for a single field -- the LastName field.

5. Make sure the Auto-populate box is not checked and press the Fields button to select the fields to populate.
6. Press the Insert button.

7. Press the ellipsis button next to Field and select the field from the file schematic dialog.
8. Provide a Title for the field. This is the label that will appear in the QBE drop-list.
9. Press the OK buttons all the way out to the Window Formatter, then Close the formatter (saving your changes).
10. Make and run the application.

The browse procedure now has the functionality you wanted. When you run a query, the window looks like this:

And it allows you to specify a range by inserting two query lines--one with a >= and the other with a <= operator. This specifies a range and gives you the query you want.

Q:

I have several reports that provide a summary on the last page. Some users need the entire report, and others only need the summary. Is there any way I can use the same report to print in either format? I know I can copy the procedure and modify it to print only the summary, but I don't want all that duplication. Is there any way I can print only the last page? Can you save me from this duplication of effort?

A:

The new, improved PrintPreview class has come to your rescue. All you need to do is set the PagesToPrint property of the Previewer object.

Look for the following embed point:

Local Objects--
     Previewer--
        SetDefaultPages 
           CODE
                Parent Call
                       <embed your code here>

Embed this code:

SELF.PagesToPrint = RECORDS(SELF.ImageQueue)
SELF.CurrentPage = RECORDS(SELF.ImageQueue)

This specifies that only the last page should print and that that page should display.

To use your report for dual purposes, merely wrap a condition around that line; i.e.,

IF <some Condition>
  SELF.PagesToPrint = RECORDS(SELF.ImageQueue)
END

Now you can use the same report for both purposes.

Q:

I like the way you can specify the action after a successful add in the SaveButton control template; however, I want to let my users decide whether they want repetitive adds or not. How can I let them set this in a "User Preferences" procedure?

A

You want your user to control the way your application behaves? GOOD IDEA! The best software allows users to define behavior. You have mastered the art of good user interface design.

Now, let's look at how we can easily accomplish this in Clarion 5.

1. First, create a global variable and define it so it can has a value of 1, 2, 3, or 4.
2. Next, populate this as a control on your user preferences procedure. This allows the user to set it.

3. 
   I used an OPTION control defined as follows:

   OPTION('Insert Mode'),AT(253,20,50,78),USE(GLO:InsertModeFlag),BOXED
   RADIO('Default'),AT(261,38),USE(?GLO:InsertModeFlag:Radio1),VALUE('1')
   RADIO('Caller'),AT(261,50),USE(?GLO:InsertModeFlag:Radio2),VALUE('2')
   RADIO('Batch'),AT(261,62),USE(?GLO:InsertModeFlag:Radio3),VALUE('3')
   RADIO('Ask'),AT(261,73),USE(?GLO:InsertModeFlag:Radio4),VALUE('4')
   END
   
   

Next in the Update Procedure, embed this code in the embed point immediately before opening the window (WindowManager, INIT, Priority 7800)

EXECUTE GLO:InsertModeFlag
SELF.InsertAction = Insert:None ! default
SELF.InsertAction = Insert:Caller ! return to caller
SELF.InsertAction = Insert:Batch ! add another
SELF.InsertAction = Insert:Query ! prompt user to add another
END
Of course, you may not want all four choices (setting the default behavior to default seems redundant, don't you think?). Just adjust this to your preferences. You can read more about the InsertAction property in the Application Handbook.

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Clarion Magazine ISSN 1718-9942