How to write code that declares variables?

Radium_Radiovich · February 4, 2015, 5:06pm

Just for the fun of it, instead of using Dictionary, I want to make a method which mimics Java’s Array which accepts other arrays as items.
I want it to create some array properties inside a module, and fill them with the given values.
Also I want to optionally flush the array properties (or better, delete them from the module. is there any difference between deleting and flushing in regards to memory allocation?) when it is not needed anymore, to simulate local variables’ habit of self destruction.
BTW, this kind of array will only store strings.

The said method would be like this:

sub SetArrayOfArrays(ArName as string, Length as integer, Info() as string)

  // Info's items must be in this format:
  // "one,two,three,four,...."
  // Each Info item will become a separate array.
  
  for each item as string in Info
    for each word as string in split(item, ",")
      for i as integer = 1 to Length

        // create array property under myModule
        // name it as ArName + "_" + str(i)
        // store word's value inside it

      next
    next
  next
  
end sub

And the method for accessing them would be like:

sub GetArrayOfArrays(ArName as string, PrimeIndex as integer, SecondIndex as integer) as string

  dim target as string
  
  // code for combining ArName and str(PrimeIndex) to refer to ArName_PrimeIndex()
  
  target = ArName_PrimeIndex(SecondIndex)
  
  return target

end sub

Please tell me how to write the code for the commented sections.

Mike_Cotrone · February 4, 2015, 5:43pm

Just out of curiosity why would you want to play with encapsulating a 1D array inside of another 1D array?

Normally what we do with Xojo is build an array of a specific type class to encapsulate.

I would create a new class called “storageClass” and assign it properties.

Property1:  indexID as Integer
Property2:  name as String
Property3:  someListing() as String

Create the Array with the “StorageClass” type

Dim awesomeArray() as StorageClass

Create a subclass by Instantiating the above Class

Dim awesomeStorageClass as StorageClass

Fill the properties of this subclasses instance:

awesomeStorageClass.IndexID = 0
awesomeStorageClass.Name = "Fantastic"
awesomeStorageClass.someListing.Append "Yup"
awesomeStorageClass.someListing.Append "Nope"

Append this class to the Array that had the same type as this class.

awesomeArray.Append  awesomeStorageClass

In the end you will have an Array of all these classes with storage capabilities and as you can see with my Array as a property of the class you can still gain a hierarchical array if you wish.

IMO this scales well in an OOP environment such as Xojo.

HTH and I am sure others will add to this:

Redim awesomeArray(-1)

Then to remove the elements of the array you could

Kem_Tekinay · February 4, 2015, 5:46pm

Mike has provided the best answer. Build classes to store your data.

You can also emulate something like what you described through the Operator_Lookup method of a class, even if this is not typically recommended.

But you cannot create nor destroy properties of a module or class at runtime.

Mike_Cotrone · February 4, 2015, 5:47pm

Kem beat me to my edits I wish we could edit our posts out of turn

Radium_Radiovich · February 4, 2015, 6:12pm

Thank you Mike and Kem!
Mike what you described solves all of the problems I was facing.
I avoided Dictionary because I was tired of getting KeyNotFoundException.
So Instead I build the required number of array properties under a module, to do my job.
But each time I wanted to do something to them, I had to copy my code 36 times and manually write the names of all 36 array properties.

[quote=164628:@Kem Tekinay]Mike has provided the best answer. Build classes to store your data.

You can also emulate something like what you described through the Operator_Lookup method of a class, even if this is not typically recommended.

But you cannot create nor destroy properties of a module or class at runtime.[/quote]

What Mike posted solves all my problems, but I still like to know how to iterate through a series of similarly named objects in a For loop by writing the constant part of the series name and appending the instance number at the end of it.

Mike_Cotrone · February 4, 2015, 6:16pm

Hopefully this is what you mean and using my example from above. Im not 100% sure what you mean on your last sentence, but hopefully you can adapt it.

FYI: I use the IndexID property of the class as my ID and/or a “isSelected” boolean so I always know which class is being used.

Dim i as integer

for i = 0 to awesomeArray.Ubound
  if awesomeArray(i).Name = "theName" Then
     // DO SOMETHING SPECIAL
     // MARK AS SELECTED
     awesomeArray.isSelected = True
 Else
     awesomeArray.isSelected = False
 End if

next i

Radium_Radiovich · February 4, 2015, 6:35pm

[quote=164637:@Mike Cotrone]Hopefully this is what you mean and using my example from above. Im not 100% sure what you mean on your last sentence, but hopefully you can adapt it.

FYI: I use the IndexID property of the class as my ID and/or a “isSelected” boolean so I always know which class is being used.

I tend to not use for each unless I don’t care about guaranteed search order.

[code]
Dim i as integer

for i = 0 to awesomeArray.Ubound
if awesomeArray(i).Name = “theName” Then
// DO SOMETHING SPECIAL
// MARK AS SELECTED
awesomeArray.isSelected = True
End if

next i

[/code][/quote]
Here’s what I meant:

Let’s say I have 40 PushButtons named myButton1, myButton2, myButton3, … myButton39, myButton40.
And I want to execute an action on every single one of them.
I want to know how can I accomplish this easily, WITHOUT first appending them inside an array to refer to them by index in a for loop.
(BTW, appending these 40 buttons to an array requires writing the names of all of them, so it kinda defeats the purpose)

Currently my method is:

myButton1.doSomething
myButton2.doSomething
myButton3.doSomething
myButton4.doSomething
...
myButton39.doSomething
myButton40.doSomething

But instead of writing all that code, I want to be able to do something like this:

for buttonNumber as integer = 1 to 40
(myButton+str(buttonNumber)).doSomething
next

Kem_Tekinay · February 4, 2015, 6:39pm

Look at the documentation for Control Sets.

Mike_Cotrone · February 4, 2015, 6:41pm

Control Sets are on p.106
http://41160df63757fc043cfd-66287f38a83954e31a54d1dbe33e0650.r4.cf2.rackcdn.com/Documentation/UserGuide-UserInterface.pdf

I don’t use these too much, but what I do know is that the control set must encompass the SAME controls (can’t have different controls in the set which would be the same as an Array that has a a specific control class type).

Radium_Radiovich · February 4, 2015, 6:50pm

Ah I forgot to mention WITHOUT using control sets
What I really want is to know how to combine two strings to refer to an object/variable.

Michel_Bujardet · February 4, 2015, 6:51pm

[quote=164650:@Radium Radiovich]Ah I forgot to mention WITHOUT using control sets
What I really want is to know how to combine two strings to refer to an object/variable.[/quote]

Basically you want the Java array …

Mike_Cotrone · February 4, 2015, 6:59pm

Radium,

If you create a container control with one button on it and set up the button how you want… Then you can Dynamically instantiate a container control (button) append to array in a loop fashion which would not require you to type out 40 names.

I do this commonly when I am presenting the UI dynamic graphs.

Julen_I · February 4, 2015, 8:22pm

Also, the controls are always in a sort of array (maybe a true array? someone more knowledgeable can clarify that) which can be looped through. Check one of the examples of the IsA operator (http://documentation.xojo.com/index.php/IsA), modified here to be used with buttons:

Dim i as Integer For i=0 to Self.ControlCount-1 If Self.Control(i) IsA PushButton then if PushButton(Self.Control(i)).name=TheName then 'do something End if End If Next

This code is intended to be used to loop through the controls present in a window (Self). I haven’t tested the code and I am not sure it is correct because I have never done this, but the concept is correct.

Julen

Radium_Radiovich · March 1, 2015, 2:30pm

[quote=164626:@Mike Cotrone]Just out of curiosity why would you want to play with encapsulating a 1D array inside of another 1D array?

Normally what we do with Xojo is build an array of a specific type class to encapsulate.

I would create a new class called “storageClass” and assign it properties.

Property1:  indexID as Integer
Property2:  name as String
Property3:  someListing() as String

Create the Array with the “StorageClass” type

Dim awesomeArray() as StorageClass

Create a subclass by Instantiating the above Class

Dim awesomeStorageClass as StorageClass

Fill the properties of this subclasses instance:

awesomeStorageClass.IndexID = 0
awesomeStorageClass.Name = "Fantastic"
awesomeStorageClass.someListing.Append "Yup"
awesomeStorageClass.someListing.Append "Nope"

Append this class to the Array that had the same type as this class.

awesomeArray.Append  awesomeStorageClass

In the end you will have an Array of all these classes with storage capabilities and as you can see with my Array as a property of the class you can still gain a hierarchical array if you wish.

IMO this scales well in an OOP environment such as Xojo.

HTH and I am sure others will add to this:

Redim awesomeArray(-1)

Then to remove the elements of the array you could[/quote]

Excuse me Mike, which parts must be done in code editor, and which by GUI?
And for parts which need to be done in code editor, where do I have to insert the codes? in open event of app?

Radium_Radiovich · March 1, 2015, 2:33pm

I want all data stored in that class to be available for the entire run duration of app.