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UTMag/RapoZine Shortcuts
Michel Fournier, July 1, 2002
Show seconds in a readable format If you need to check elapsed time with seconds() or a datetime value, this function allows you to display the elapsed time in a human-readable format, that is, hours:minutes:seconds, instead of the total number of seconds. Just pass a number of seconds as...
Show seconds in a readable format
If you need to check elapsed time with seconds() or a datetime value, this function allows you to display the elapsed time in a human-readable format, that is, hours:minutes:seconds, instead of the total number of seconds. Just pass a number of seconds as a parameter.
function TimeString(tnTotalSeconds)
local lnRemainingSeconds,lnHours,lnMinutes,;
 lnSeconds
lnHours=int(tnTotalSeconds/3600)
tnRemainingSeconds=tnTotalSeconds%3600
lnMinutes=int(tnRemainingSeconds/60)
lnSeconds=tnRemainingSeconds%60
return alltrim(str(lnHours))+":"+;
 padl(lnMinutes, 2, "0")+":"+;
 padl(lnSeconds, 2, "0")
endfunc

by Hilmar Zonneveld

How to add custom properties with SCATTER
Instead of trying to add properties with some third-party tools like ADDPROP5.FLL to the native object created with SCATTER NAME command you may try to approach this problem from the other side.

You can replace the native SCATTER command with your own function MYSCATTER which may work on any area and create the object from one of standard VFP classes and use its native .AddProperty method. Here is the sample of such function.

Then you go to the record you need by using the following.

Note that you still can use the native GATHER command here.

The scope of scattered1 variable and other code safety features are up to you. Keep in mind also that the FoxPro reserved words (commands, function names and PEMs names) should not be used as the field names.

by Nick Neklioudov

Open any document
The following function will open any document, with its default association (the same application that will be called when you double-click on the file, in Windows Explorer). Use it to open a text-file, a Word or Excel document, an image, etc., with an external application.

This is simply a slightly adapted version of UT FAQ#190 ("Starting the default Web Browser from VFP"), by Gérald Santerre (he suggested I create a separate FAQ).

You might use this function to open a Word document, an Excel spreadsheet, an HTML-file, a text-file, an image, and many others, with an external application.

Please note that you may get an error when you don't pass the full path of the file.

View code

by Hilmar Zonneveld

Breaking Inheritance
Four easy and fun ways to get yourself into trouble with inheritance.

A frequent source of problems in OOP is called "breaking inheritance". This document briefly describes what inheritance is, how it applies to properties and methods, and how it can be maintained or broken. Problems appear especially when inheritance is broken in methods.

Inheritance with Properties

When creating an object or class based on another class, the child object (or class) initially inherits properties and methods from the parent class.

Example: Create a form class with a blue background. Use it as an ancestor (parent, grandparent, etc.) of all your forms. Now, all forms will have a blue background. Changing the background to red will change all forms based on it to red.

Now, if you change the background in the child (in the properties sheet) to gray, inheritance is broken; changes in the parent will no longer be reflected in the child. If you ever want to restore inheritance, right-click in the properties sheet, and select "restore to default".

Inheritance with Methods

With methods, the situation is slightly more complicated. Often, you want to add additional commands, but still call the default (inherited) method.

However, as soon as you type anything in the child method code, the parent method code is no longer called automatically. Please note that "Restore to default" will erase the entire code in the child method.

You solve this by explicitly calling the parent method with command DoDefault(). Often, you would place this at the beginning or at the end of the inherited method. Sometimes, you may want to conditionally call the inherited method.

VFP 3 doesn't have DoDefault(); instead, you use an operator with the queer name of "scope resolution operator", which requires specifying both the parent class and the method.

* Examples, for method Init(); parent class is cForm
* Example in VFP 5 or later:
DoDefault()

* Example in VFP 3:
cForm::Init()
From now on, I will assume that you can use DoDefault().

Please note that DoDefault() can both accept parameters (which are passed to the parent method), and return a value (the value returned by the parent method).

Easy instructions for getting into trouble

And now, finally, the fun part. Basically, I managed to get into trouble, by breaking inheritance, in four different ways. In case you ask, yes, I really did get into trouble, on different ocassions. I know how to break inheritance and how to avoid it, but it is still easy to forget some detail in method code. I believe that most programmers will use at least the first three ways to get into trouble, sooner or later.

1) The most obvious is to include code in the derived object, and simply forget DoDefault().

...Breaking Inheritance
* MyForm.Init()
set talk off
set deleted on
* DoDefault() isn't included, and the parent method won't be called.
Corrected version:
* MyForm.Init()
DoDefault() && This will call the parent method
set talk off
set deleted on
This is a quick sample only. In actual practice, "set deleted on" would be placed in the parent-of-all-forms, and it would be placed in the Load() method.

2) Forget that the parent method may require parameters

* MyForm.Init()
lParameters par1, par2  && This was automatically inserted by the method editor,
     && because the parent method had parameters
DoDefault()  && Parameters???
set talk off
set deleted on
Corrected version:
* MyForm.Init()
lParameters Par1, Par2
DoDefault(Par1, Par2)  && Parameters will be passed to the Init() of the parent
set talk off
set deleted on

3) Forget that the parent method may return a value

* MyForm.Init()
DoDefault()  && Return value???
set talk off
set deleted on
Corrected version:
* MyForm.Init()
local llReturnValue
llReturnValue = DoDefault()
set talk off
set deleted on
return llReturnValue
In the above sample, I am assuming that there are no parameters.

4) Forget that a parameter may be an array

...Breaking Inheritance
* MyForm.Init()
lParameters taPar1, tcPar2   && taPar1 is an array
DoDefault(taPar1, tcPar2)  && Only the first element will be passed!
set talk off
set deleted on
Corrected version:
* MyForm.Init()
lParameters taPar1, tcPar2
DoDefault(@taPar1, tcPar2)  && Entire array is passed by reference
set talk off
set deleted on
The following useful information was e-mailed to me by Sherlog; it affects cases where the number or type (array or not) of parameters isn't known in advance:

... you should always forward parameters per reference because this is the only way to preserve the parameter semantics of the function you are forwarding to.

Strictly speaking even that is not enough; the full procedure for semantics-preserving forwarding would be like:

lparameters a, b, c  && and possibly more (up to 27 total) ...
local nArgs, xResult
nArgs = pcount()
do case
   case m.nArgs < 1
      xResult = dodefault()
   case m.nArgs == 1
      xResult = dodefault(@m.a)
   case m.nArgs == 2
      xResult = dodefault(@m.a, @m.b)
   * more cases as needed ...
endcase
Fox itself uses code like that in several places, BTW.

However, if you know that the called function/method does not use parameter counting - a good reason not to do it in your own code <g> - then passing all parameters per reference is enough of a precaution.

by Hilmar Zonneveld

An alternative to build SQL statements
I have never liked to build SQL statements doing concatenation. Very often, I build my SQL statements on the MS-SQL Server's Query Analyzer, and then, cut-and-paste it into some PRG file. Then, it's that chaos of breaking the string and concatenate it. Like this:
Local lcSQL
lcSQL = ""
lcSQL = lcSQL + "Select Field1, Field2, Field3, Field4 "
lcSQL = lcSQL + "From Table "
lcSQL = lcSQL + "Inner Join AnotherTable "
lcSQL = lcSQL + "On Table.SomeField = AnotherTable.SomeField "
lcSQL = lcSQL + "Inner Join FooTable "
lcSQL = lcSQL + "On Table.Somefield = FooTable.SomeField "
lcSQL = lcSQL + "Where Field1 = " + lcSomeVar
lcSQL = lcSQL + " And Field2 = " + lcAnotherVar
lcSQL = lcSQL + " Group by Field3, Field2 "
lcSQL = lcSQL + " Order by Field1 "
I really hate that. With VFP 7 came my remedy for this situation. I can simply cut the code from the Query Analyzer into my PRG (or any other place) and then do something like this:
Local lcSQL
Text to lcSQL TextMerge NoShow
   Select Field1, Field2, Field3, Field4 
     From Table 
     Inner Join AnotherTable 
       On Table.SomeField = AnotherTable.SomeField 
     Inner Join FooTable 
       On Table.Somefield = FooTable.SomeField 
     Where Field1 = << lcSomeVar >>
       And Field2 = << lcAnotherVar >>
     Group by Field3, Field2 
     Order by Field1 
EndText
A lot cleaner, isn't it? Of course, this will add some Chr(13)+Chr(10) on the string, which can cause some trouble somewhere. Well, you can just clean that with such code:
StrTran(lcSQL, Chr(13)+Chr(10), " ")

Well, I like to do such thing. <s>

MSN Messenger automation

Do you need to automate the MSN Messenger, making it send messages for you? See how simple it is:

*-- Instantiate the MSN Messenger
oMSN = CreateObject("Messenger.MessengerApp")
*-- Assuming you have informed MSN to remember your Logon info...
oMSN.AutoLogon()
*-- Launch "Instant Messaging User Interface"
oConversation = oMSN.LaunchIMUI("yourbuddie@hotmail.com")
oConversation.SendText("Hi, dude! Wasssup!!!")
*-- Access the log of the session conversation
? oConversation.History

by Claudio Lassala

Michel Fournier, Level Extreme Inc.
Michel Fournier is a professional, visionary, perfectionist, mostly known for his renowned realizations over the years, designer, architect, owner of the « Level Extreme Platform », formerly known as the « Universal Thread », recognized as one of the longest running Web sites of the planet, also known as a precursor to social networking, product manager, Internet serial entrepreneur, practiced Lean Startup techniques long before they were known, out of the box thinker, using the tenth man rule, specializes in building entire virtual data center solutions, has provided high end IT consulting worldwide, has owned and operated three companies, delivered worldwide renowned e-commerce Web sites, designed and architected two world class top level development frameworks, wrote over 100 IT articles for various sources, presented at user groups, conventions and corporations nationwide as well as in the US, has provided his contribution in political and legal issues to provide a better world, Owner and Senior IT Consultant at Level Extreme Inc., former Architect Software/Application & Project Manager, 7 times Microsoft Most Valued Professional for VB.NET, 7 times Microsoft Most Valued Professional for Visual FoxPro, Developers Choice award for best site at VFP DevCon 2000 Connections in New Orleans, featured in Acadie Nouvelle on October 2003.
More articles from this author
Michel Fournier, February 1, 2007
From the Level Extreme .NET Framework, this small class allows a developer to manipulate easily the content of a directory by the use of a dataset. With the setup of a few properties, a call to the method and the access to the object dataset, you can have access to the file properties of the directo...
Michel Fournier, August 1, 2001
It is interesting to see how something new can evolve. This is the case for the Universal Thread Magazine. We are now at our 3rd issue and we are already overbooked by scheduled articles and hot stuff we have to cover for the upcoming issues. Publishers are sending request for book reviews, wri...
Michel Fournier, October 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, May 1, 2006
In this article, Michel Fournier is providing a small introduction to manipulating XML data from VB.NET. The use of XML is now widely used for various purposes such as exchanging data between application, platforms and other environments. XML is a simple and very flexibile text format that can be ma...
Michel Fournier, October 1, 2001
In our daily things we do, sometimes we find ourselves in unexpected situations. Such situations, either in our personal life or from our professional work, require some adjustments in order to walk through them. The ability to take some time to take an overall look of what is happening, apply a bas...
Michel Fournier, March 1, 2007
In this small article, Michel discusses a problem he recently encountered when converting a dataset into XML to be used later on with a XSL transformation to export into an Excel sheet. When null values were present in the dataset, this was creating weird result. This article provides a quite alte...
Michel Fournier, February 1, 2006
This article discusses a simple banner fonctionalities function which can ease the display of banners on Web sites. If your Web site displays banners in GIF, JPG of Flash format, this function could be useful to you.
Michel Fournier, January 1, 2006
There are various ways to authenticate a user to a Web Service. This article discusses one way to do it by the use of Cookies. As it could the case with a Web page sending a cookie to the browser, the same can be used from within a Web Service.
Michel Fournier, February 1, 2006
This article is a follow up on the first part of this article which appeared on our January 2006 issue. In this one, Michel discussed further implementation of getting the authentication from a members table as well as setting up a session per user.
Michel Fournier, December 1, 2003
Visual FoxPro and .NET are two great environments to build business applications with. But, fantastic they are when you combine them together in order to increase the strenght of the flexibility to respond to your client needs. In this article, I will demonstrate a case study in regards to a new ser...
Michel Fournier, December 1, 2002
Over the years, I have been involved in several types of desktop and Web applications. Every time you start a new project, there is always something new you will learn. In this article, I would like to detail some of the issues which are to be considered when delivering a Web based application. Thos...
Michel Fournier, January 1, 2003
This article is a follow-up with more advanced details in regards to the first article of this series in our December issue which included a tip on dealing with stylesheets. This one allows you to customize your HTML code based on the user, assuming each user has some ways to setup some specific sty...
Michel Fournier, March 1, 2003
The first two articles of this series have been published in the issues of December 2002 and January 2003. In this one, I will talk about graphic issues, how to negotiate with a form to launch his transaction to either within the same window or a new one, how to gather values from one page to anothe...
Michel Fournier, April 1, 2003
In this article, I will proceed with considerations about HTTP server variables being received from a browser and about considerations for opening new windows in your Web application. Relying on the protocol or not When it first started, we didn't ask that question to ourselves as to know ...
Michel Fournier, April 1, 2009
This articles describes the use of CDO.Message to gain the ability to retrieve a URL as a MHT file. It also covers an interesting approach to retrieve a URL even if this one requires a login.
Michel Fournier, January 1, 2006
Data dictionaries has its use and also for Web applications. I see many developers building Web applications who forget about many structured that used to be in place when developping desktop applications. The same should apply for Web applications as it is no different. This article discusses some ...
Michel Fournier, June 1, 2003
DevTeach was held in Montreal from May 10-13, 2003. It presented a new breed of conference. Sessions included both presentation material and, whenever possible, hands-on training. DevTeach brought under the same roof the best speakers available for .NET, SQL Server and Visual FoxPro as well as Micro...
Michel Fournier, May 1, 2002
The Essential Fox conference was held this weekend in Independence, MO. Once again, the Universal Thread team was on site to do the official coverage of the event. It has been a great success, well planned by Russ Swall, the event owner, and his team and well appreciated by the attendees. A total of...
Michel Fournier, April 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez Claudio Rola José Cavalcanti Moacyr Zalcman Ricardo Soares Fábio Vieira ...
Michel Fournier, September 1, 2001
Ever wonder how to successfully and rapidly display HTML lists to your users? Well, we all probably already did. However, its implementation differs a lot from sites to sites as we all have our own different approaches. Delivering Visual FoxPro data to the Web as if you would be in Visual FoxPro is ...
Michel Fournier, November 1, 2001
A lot of things happened recently in the Visual FoxPro world and for related technologies. The Great Lakes Great Database Workshop was being held in Milwaukee from Sunday October 27 to Wednesday October 31. That conference which primaly focused on Visual FoxPro has covered a lot of technologies...
Michel Fournier, November 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, December 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, January 1, 2003
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Rodolfo Duarte Fábio Vazquez Moacyr Zalcman Martín Salías Antonio Castaño Fabián Belo Rafae...
Michel Fournier, November 1, 2001
I have been following several threads on the Universal Thread recently about FTP from Visual FoxPro. I have used an ActiveX for a while to do such a task. I have found that years after years, the problem is that you have to maintain that ActiveX for your own workstation and for every servers or work...
Michel Fournier, July 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, January 1, 2006
With the beginning of the new year, Michel resumes some of the highlights of the Universal Thread and what is coming up for the new season.
Michel Fournier, March 1, 2006
When comes time to display the content of a memo field on a Web page, one common task we have to do is to hyperlink specific content. This article discusses about a technique which can be used to hyperlink various types of links as well as email addresses.
Michel Fournier, April 1, 2009
This article describes some basic techniques to manipulate some images in .NET. It covers image resizing, image cropping and the ability to save an image into a JPG high resolution format.
Michel Fournier, May 1, 2007
This short articles provides an approach of important data from an Excel sheet into your application without having the requirement of having Excel installed on the server.
Michel Fournier, August 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, July 1, 2001
Recently, I was having problems while working on several projects on my PC. The problems were happening when I had several applications open at the same time. When the problem occured, I had to reboot my PC and then was able to work for a few hours up to a few days until the next reboot. As I was wo...
Michel Fournier, June 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, September 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Co-editor Martín Salías Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira M...
Michel Fournier, January 1, 2001
Xitech (Europe) produces tools for the Windows software developer. They specialize in FoxPro Developer tools, data and code recovery and security. In this article, we will see an overview of 5 of their tools. You will find more details about each of them from Xitech documentation. To get Xitech cont...
Michel Fournier, April 1, 2006
This article discusses the ability to use Visual FoxPro to schedule a list of tasks to be executed at specific intervals. While there could be the approach of using the Windows Scheduler to execute those tasks, it is always interesting to be able to control everything from within VFP. A small VFP sc...
Michel Fournier, April 1, 2006
This article describes an overview of sending an email from VB.NET. It covers the basis of creating the email functionality in a class and using an instance of that class to define and send the email. The class includes the ability to send to multiple recipients as well as sending attachments. Sendi...
Michel Fournier, July 1, 2002
This is a follow up on my previous article on using SOAP protocol for authentication that appeared in our December 2001 issue. That article was mentioning the use of the SOAP header for authentication such as being able to identify the user for any upcoming hit to your Web Service as soon as the Log...
Michel Fournier, May 1, 2002
UTMag/RapoZine team Editors Michel Fournier Claudio Lassala Translation coordinators Claudio Lassala Martín Salías Translators Eduardo Vidigal Rodolfo Duarte Fábio Vazquez José Cavalcanti Moacyr Zalcman Fábio Vieira Martín Salías Antonio Castañ...
Michel Fournier, July 1, 2002
From recent discussions I had, with several persons from my team, about common patterns which occur in the evolution of the Universal Thread, I thought it would be nice to write an article about it. Basically, within the evolution of a product, there are some similitudes which are sometimes interest...
Michel Fournier, June 1, 2001
Welcome to our first issue of the Universal Thread Magazine. We kept receiving many requests to have such a media available on the Universal Thread, so we decided to release our first issue this month. Many people have mentioned an interest to either have such a magazine for the pleasure to read abo...
Michel Fournier, December 1, 2001
The Visual FoxPro Zone evolves As many of you may have seen, the Universal Thread Visual FoxPro Zone is evolving quite fast. In the last month, we added new content in it. As usual, the most popular option is the Toledo Wish List. Several entries are created every day. This is the place to co...
Michel Fournier, January 1, 2002
It's January 3rd, 2002, I am writing this editorial at 20h32 EST. The Christmas break is over but was it really a break? More and more, years after years, I keep seeing a lot of persons online during Christmas day or a few minutes before the new year. And, I mean, they are online as per their own ti...
Michel Fournier, January 1, 2004
In December 1993, a great history started when a small Web site known as the Visual FoxPro Yellow Pages started. Basically, a site providing ads for Visual FoxPro developers such as jobs and consulting services. Known also as the first Visual FoxPro site, it has evolved quite fast during the first t...
Michel Fournier, January 1, 2006
In the recent months, I have been involved in settings various projects at client sites, as well as for Level Extreme Web sites, which involved the support of uploading image files from an Internet browser. The process of supporting that capability in your application, either from a desktop of from ...
Michel Fournier, December 1, 2001
The Microsoft SOAP client provides access to any Web Service. Once the object is instantiated and the location of the WSDL file given, you are ready to go to access any method. Thus, based on what is supported by the Web Service, you can query to obtain various types of content such as string and bo...
Michel Fournier, February 1, 2002
On January 15th, 2002, an important joint took place for our magazine. The Universal Thread Magazine and RapoZine magazine, an online magazine available for the Portuguese developers community, joined to create UTMag/RapoZine. Effective from this issue, both magazines will offer the same technical c...
Michel Fournier, August 1, 2002
Updating your DLL on IIS This has been a common question in the recent months on the Universal Thread. More and more, developers have the need to use a DLL under IIS. However, the fun part comes when you need to update it. As soon as it kicks in, you can't update your DLL anymore as it re...
Michel Fournier, November 1, 2002
Use MemLines() to wrap text lines When you need to wrap some text at a given width (say 75 characters per line), you do it easily with: SET MEMOWIDTH TO 75 lcMemo = lcNewMemo = "" _MLINE = 0 FOR i= 1 TO memlines(lcMemo) lcNewMemo = lcNewMemo ; + MLINE(lcMemo,1,_MLINE...
Michel Fournier, September 1, 2002
Getting image width and height Probably the most flexible way to extract the width and height of an image is by the use of the image object. All is needed is to load the image in the object and get the values from the Width and Height properties. LOCAL loImage,lnWidth,lnHeight loIma...
Michel Fournier, October 1, 2002
Extracting BMPs from general fields As a complement with last issue's article on image handling, yo can find useful this little function. If you got convinced that using general fields to handle images is a bad idea, you can decided go back to independent image files. But then you'll...
Michel Fournier, June 1, 2001
It was a year ago. The DevConnections team was holding the Visual FoxPro DevCon 2000, the SQL Server Connections and the DevCon 2000 in New Orleans, Louisiana from May 14 to 18, 2000. For the first time, attendees were able to attend sessions from more than one conference at the same time. This offe...
Michel Fournier, September 1, 2001
Is there a speed limit on the Internet? Probably not, because there is so much things we can do in a short time about delivering various type of content to the community. I remember a week ago we shared an idea about helping the promotion of user group activities around the world. A week ago it was ...
Michel Fournier, March 1, 2002
In the last month, we received dozens of emails from satisfied persons in regards for our initiative of opening the magazine and the Universal Thread in general for additional communities such as the Portuguese and Spanish communities. Regulars members of the Universal Thread, new members, Microsoft...