Passing variables between forms

[thegame8311]

In the parent form is this:

Do Form Add with T_Name to Team_Name

In the form's init that is called

LPARAMETERS Team_Name

IF NOT USED("LivePlayers")
	USE LivePlayers IN 0
ENDIF

IF NOT USED(Team_Name)
	USE (Team_Name) IN 0
ENDIF

Team_Name is the T_Name from the first name

For some reason I can't get the variable to stick on the form

the variable Team_Name has either .T. or .F.

so why is the variable not passing from the first form to the second form

 

[Mike Lewis]

The parameter (Team_Name in your example) is only visible to the Init method. If you want to use it elsewhere in the form, you need to create a custom form property, and store the parameter in that property. That way, other parts of the form will be able to access the value by referencing the property.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[Mike Lewis]

Or, are you saying that you can't return the value to the caller?

To return a value from a form, you need to use a RETURN statement in the form's Unload method.

Note that you can only return a value from a modal form.

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[EzLogic]

Like mike said:

in the init of the form,

Parameters team_name
if empty(team_name)
  return .f.
endif 
if not used(team_name)
  return .f.
endif 
this.AddProperty("curTeamName",Team_Name)

in other are of the form now

lcCurTeamName = thisform.curTeamName
select (lcCurTeamName)

Ali Koumaiha
TeknoSoft Inc.
Michigan

 

[thegame8311]

Well he is what I am doing in the next forms add button:

this is in a button click event. lPlyr came from a listbox selection

LOCATE FOR &lcCurTeamName..Player = lPlyr
			IF !FOUND()
				INSERT INTO (lcCurTeamName) (Pos, Player, Team, Start_Sit);
					Values (lPos, lPlyr, lTeam, .F.)
			ELSE
				boxtype = 0 + 64

				MESSAGEBOX("Player not added", boxtype, "Selection Cancelled")
				
			ENDIF

And I have now put in the suggestion from above, with the select statement.

When I click the button from the first form, that calls the second form, it does not really do anything

If you need more code for clarification I can provide it

 

[EzLogic]

Is the code you just provided in the 2nd form i assume, right?

and the 2nd form is receiving the cursor name and you're storing it as a property?

what is the code in the click event of the 1st form that fires/calls the 2nd form?

Ali Koumaiha
TeknoSoft Inc.
Michigan

 

[Mike Lewis]

When I click the button from the first form, that calls the second form, it does not really do anything

More to the point, what happens when you click the Add button in the second form?

Also, I don't see why you are using a variable for the cursor name. Why not just hard-code the name? Or am I missing something?

Mike



__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

Yes the code I provide in above is in the second form

No, in the form's init the Parameters Team_Name = .F.

the code for the calling form click event is the following

FOR nCnt = 1 TO ThisForm.list1.ListCount
      IF ThisForm.list1.Selected(nCnt)  && Is item selected?
         T_Name = ALLTRIM(chteam.list1.List(nCnt, 2)) && Show item
      ENDIF
   ENDFOR

DO FORM AddPlyr TO T_Name

 

[thegame8311]

Currently nothing happens since the parameter Team_Name = .F.

To answer your question mike, the Team_Name will not be the same every time, it comes from the selection in the listbox on the calling form

 

[Olaf Doschke]

Perhaps you understand, if I combine your code with Teknosofts code:

LPARAMETERS Team_Name

* parameter check: Team_Nam should be valid (!)
* if the team_name is empty, return:
if empty(team_name)
  return .f.
endif 

* this check is nonsense, as you want to open that table below...
*if not used(team_name)
*  return .f.
*endif 

thisform.AddProperty("AliasTeamName",Team_Name)

IF NOT USED("LivePlayers")
    USE LivePlayers IN 0
ENDIF

IF NOT USED(thisform.AliasTeamName)
    USE (thisform.AliasTeamName) IN 0
ENDIF

And in other code you need to know the table Name, you need to refer to Thisform.AliasTeamName, eg

...
Select (Thisform.AliasTeamName)
LOCATE FOR Player = lPlyr
IF !FOUND()
...
ELSE
...
ENDIF

or

Local lcAliasTeamName
lcAliasTeamName = Thisform.AliasTeamName
...
LOCATE FOR &lcAliasTeamName..Player = lPlyr
IF !FOUND()
...
ELSE
...
ENDIF

BUT: For the third time a warning here about LOCATE &somealias..somefield:

LOCATE moves the recordpointer IN THE CURRENTLY SELECTED WORKAREA/ALIAS until it finds a record satisfying the locate condition.

If the condition is &somealias..somefield = somevalue this condition is checked, but the records of &somealias. are ONLY scanned, if this alias is the currently selected alias OR is related to the currently selected alias via a RELATION.

So in the normal case you better SELECT(somealias) and then LOCATE somefield = somevalue. LOCATE &somealias..somefield = somevalue is NOT making this foolproof, in contrast it may not look where you think it does!

I already gave code prooving this in another thread.

Bye, Olaf.

 

[JRB-Bldr]

When I click the button from the first form, that calls the second form, it does not really do anything
Currently nothing happens since the parameter Team_Name = .F.

Have you learned to use the SET STEP commands in VFP?

If you need to investigate what is happening (or what is not happening), you can insert SET STEP ON while you test execution in the Development mode.

That will automatically open the TRACE Window and allow you to interrogate variable values and 'watch' code line execution.

If you do that you will get beyond the vague descriptions such as "Nothing Happens" and be able to tell us EXACTLY what is going on so that we can better focus answers and not have to GUESS as much regarding your MANY 'challenges'.

Again, while we applaud you efforts to learn VFP, you have SO MANY questions all running concurrently on this forum that it is hard to know which challenges are contributing to other questions and which you have resolved COMPLETELY.

When people have given you code or method approaches to resolve the individual problems, have you implemented these or have you continued in your problematic, poorly designed approach?

You need to get EVERYTHING to a point of stability one way or another. Then from that stable platform, attack each new challenge one-at-a-time so that one problem will not 'cascade' into another.

Good Luck,
JRB-Bldr

 

[Mike Lewis]

Your code shows you are calling the second form like this:

DO FORM AddPlyr TO T_Name

If that's right, you are not passing the parameter to the second form. That would explain why it is appearing there as .F.

You need to do something like this:

DO FORM AddPlyr [b]WITH[/b] T_Name

Also, according to your code, you are calling the second form even if there is nothing selected in the list box. Is that what you intend?

Mike

__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[thegame8311]

No i did not intend for it to do it with nothing selected.

my other problem at the moment is that the variable with the team name does not seem available to the entire form that is called.

The variable contains the name of a table. I want the contents of that table to be displayed in a listbox, the values store into the listbox but when I try to do this in the listbox init:

USE (lcCurTeamName)

thisform.list1.RowSourceType = 2
thisform.list1.RowSource = (lcCurTeamName)
thisform.list1.Listindex = 0 
thisform.list1.ColumnCount = 4
thisform.list1.ColumnWidths = "0, 50, 150,150

it says variable lcCurTeamName not found. I don't understand it's in the init of the form

 

[EzLogic]

lcCurTeamName = thisform.curTeamName && or whatever property name you gave it.

assuming thisform.CurTeamName was handled in the init of the form.

Ali Koumaiha
TeknoSoft Inc.
Michigan

 

[Dan Freeman]

In the Xbase programming language, variables have a scope (either Public, Private or Local). All variables except for Public exist ONLY as long as the procedure that creates them.

A variable created in INIT goes out of scope and disappears when the INIT finishes.

Store the value in a form property, which exists as long as the form itself exists. Retrieve the value from the form's property in any method other than INIT.

This is just the way the programming language works and it's good to learn it now.

 

[thegame8311]

Well in the init of the form is:

Parameters Team_name
if empty(Team_name)
  return .f.
endif 
if not used(Team_name)
  USE (Team_name) IN 0
endif 
this.AddProperty("curTeamName",Team_Name)

I know that "this" refers to the form and AddProperty is a method
so by calling the AddProperty isn't that mean it's still available to the rest of the form?

 

[Dan Freeman]

It does if you actually pass the value, don't have any typos, and later retrieve the same value.

I believe Mike showed that you weren't passing the value at all.

You appear to be adding a property named "curTeamName" (a LOUSY name that many will confuse with the name of a cursor) and later referring to a property named AliasTeamName, which is a different name entirely.

But that's just going from the code you've posted here.

 

[Mike Lewis]

TheGame,

Why don't you take a few moments to read over all the replies you've received so far.

I believe we've answered your questions. The trouble is that, whenever one of us posts a reply, you respond by introducing a new variation on the problem. And when we suggest a solution, you don't tell us if it worked or not.

We're trying to help you, but you're not making it easy for us.

Mike





__________________________________
Mike Lewis (Edinburgh, Scotland)

Visual FoxPro articles, tips, training, consultancy

 

[Dan Freeman]

We're trying to help you, but you're not making it easy for us.

You have a talent for understatement.

These conversations do tend to carom a bit, don't they?

 

[Olaf Doschke]

Two simple problems with what you have applied so far:

Parameters Team_name
if empty(Team_name)
return .f.
endif

If you don't pass in anything, Team_name will actually be empty, so empty(Team_name) is true, so the init does return .f. here, and what you might not yet know, this leads to the form not running, which corresponds to your observation "nothing happens".

Also you might have your code of the listbox in the listbox init, which runs prior to the form init, which again is something you first need to know about event order.

Both of these missing informations would be revealed, if adding breakpoints or SET STEP ON to use the debugger trace window and see step by step what is going on. If something does not work, put a breakpoint a point you know still works, in this case perhaps even before the DO FORM, as the whole form doesn't work out, then you'll already reveal the one or other problem, eg code execution never arriving at a point of code you try to mend.

So take two advices from this:
1. just providing the code you have so far also isn't enough to judge what's perhaps not working, it's also important to know in what method or event the code is located, because of the order of code running. Eg you can't access a form property before it exists.

2. The debugger is your friend and set step on gives you much more insight on thigs happening and having happend than just error messages do. The latter only point you to a point of failure, not the root problem.

Bye, Olaf.