CODEWITHSUNDEEP
loopspowerbuildervariable-names
user
user

Reputation: 3

Make variable name using loop and string in PowerBuilder

I am interested if it is possible to make variable name in PowerBuilder using a loop and a string. For example:

long ll_go
string lst_new
for ll_go = 1 to 8
  lst_new = "text" + ll_go
  lst_new.tag = 5500
next

So, it should give me variables text1, text2..,.,text8 and I would be able to assign values for them. Let me know if anybody succeeded, thanks in advance

Upvotes: 0

Views: 4197

Answers (5)

Seki
Seki

Reputation: 11465

Your description is lacking some term precision.

If you actually want to dynamically create new variables as "variable in a powerscript subroutine or function" this is simply not possible.

If instead you want to create dynamically some new controls statictext or textedit objects in a window or visual userobject this is possible:

  1. use a local variable of the type of the new object you need to create, e.g. static text
  2. make it a live object (instantiate) with create
  3. set the object properties to whatever you need
  4. "attach" the new object to its parent (either a window or a visual userobject - though any graphicobject is possible with using the win32api SetParent function) with the OpenUserObject() method. Note that you cannot simply add it directly to the parent's Control[] array.
  5. you can also keep the object in your own array for later convenience access to the created objects instead of looping on the Control[] array
  6. once the object is attached it its parent, you can reuse the local variable to create another one

Here is an example:

//put this in a button clicked() event on a window
//i_myedits is declared in instances variables as 
//SingleLineEdit i_myedits[]
SingleLineEdit sle
int i
for i = 1 to 8 
    sle = create singlelineedit
    sle.text = string(i)
    sle.tag = "text_" + string(i)
    sle.height = pixelstounits(20, ypixelstounits!)
    sle.width = pixelstounits(100, xpixelstounits!)
    parent.openuserobject(sle, pixelstounits(10, xpixelstounits!), pixelstounits(22 * i, ypixelstounits!))
    i_myedits[i] = sle //keep our own reference
next

An exemple of values access:

//put that in another button clicked() event
SingleLineEdit sle
int i
string s_msg

for i = 1 to upperbound(i_myedits[])
    sle = i_myedits[i]
    if i > 1 then s_msg += "~r~n"
    s_msg += "edit #" + string(i) + " (" + sle.tag + ") says '" + sle.text + "'"
next
messagebox("Edits values", s_msg)

Result

As you can see, one practicality problem is that you cannot refer to these controls by constructing the control's name like "text"+2, instead you must access the my edits[] array or loop through the controls and test their .tag property if you set it to something specific.

Upvotes: 1

Rich Bianco
Rich Bianco

Reputation: 4174

Yes, and there are more than one way to skin a cat.

Sounds like you have several properties so I'd use an array of custom non visual user objects, or an array of structures. Otherwise you could probably use something from the .NET framework like a dictionary object or something like that, or a datawidnow using an external datasource, where you can refer to column names as col + ll_index.ToString().

SIMPLE Example:

Make custom NVO with following instance variables, plus getter/setter functions for each, name it n_single_field

// add the properties and recommend getter and setter functions
public string myTag
public string myText
public int myTabOrder
...

// To USE the NVO define an unbounded array
n_single_field fields[]

// to process the populated fields
integer li_x, li_max_fields

// loop through field 1 through max using array index for field number
li_max_fields = upperbound(fields)
for li_x = 1 to li_max_fields
    fields[li_x].myTag = 'abc'
    fields[li_x].myText = 'text for field number ' + li_x.ToString()
    fields[li_x].myTabOrder = li_x * 10
next

Maybe I'm oversimplifying if so let me know, if there is a will there is always a way. ;)

Upvotes: 0

Hugh Brackett
Hugh Brackett

Reputation: 2706

You can't create a variable name in a script because the variables have to be declared before you can use them. With PBNI it's possible to generate a name the way you describe and then get a reference to a variable of that name that already exists but I don't think that's what you want. If you want to keep track of additional properties for your controls, just inherit a new user object from whatever it is (sle, mle, etc.) and add the properties you want. Then you can place your user object on a window and use the properties. Another approach is to use the control's Tag property. It holds a string that you can put whatever you want in. PFC uses this technique. Terry's DataWindow solution is a good approach for storing arbitrary data.

Upvotes: 0

Terry
Terry

Reputation: 6215

I'd see two ways to do this, but they aren't as easy as it seems that you were hoping:

1. Control Array

First method would be to go through the control arrays (on windows, tabs and user objects). I'd create a function that took the control name as a string, then another that overloaded the same function and took control name and an array of windowobject. The string-only method would just call the string/array method, passing the string through and adding the window.Control as the second parameter. The string/array method would go through the array, and for each element, get the ClassDefinition. Pull the name off of it, and parse it apart the way you want it to match the string parameter (e.g. for w_test`tab_first`tabpage_first`cb_here, do you want cb_here to match, or tab_first`tabpage_first`cb_here?). Deal with matches as appropriate. When you find a control of type tab or user object, call the string/array function again with the Control array from that object; deal with success/fail returns as appropriate.

2. DataWindow

What you're describing works extremely well with DataWindows, and their Describe() and Modify() functions. Since you pass these functions only a string, you can build not only the control names, but the values they're set to as you would build any string. In fact, you can build multiple Modify() strings together (delimited by a space) and make a single call to Modify(); this is not only faster, but reduces window flicker and visible activity.

Don't fall into the trap of thinking that, since your data isn't from a database, you can't use a DataWindow. Create an external DataWindow, and simply use it with one row inserted during the Constructor event.

As you might guess, I'd strongly favour the DataWindow approach. Not only is it going to perform better, but it's going to provide a lot more flexibility when you want to move on and tag more control types than just static text. (You'll have to do some type casting even with one control type, but if you want to get into multiples, you'll need to start a CHOOSE CASE to handle all your types.)

Good luck,

Terry

Upvotes: 0

DARKinVADER
DARKinVADER

Reputation: 640

I do not think that it is possible. Workaround could be an array maybe.

Br. Gábor

Upvotes: 0

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