New feature - inline casting

Erel · Jun 28, 2021

B4X:

Dim Buttons As List = Array(Button1, Button2, Button3, Button4, Button5)
Dim btn As B4XView = Buttons.Get(1)
btn.Text = "boring" 

Buttons.Get As B4XView(2).Text = "less boring"
Button5.Text = Buttons.Get As B4XView(2).Text
 Dim m As Map = CreateMap("ttt": " 123 ;lkasd  ")
Button4.Text = m.Get As String("ttt").Trim
Root.GetView As WebView(8).LoadURL("https://www.b4x.com") '8 is the view's index

Alexander Stolte · Jun 28, 2021

Erel said:
'8 is the view's index

A numbering in the designer would be very useful to find out faster the index of a view, with 20 views this is often exhausting.
0
1
2
___0
___1
___2
3
4

MarcoRome · Jun 28, 2021

Hi @Erel is very interesting.
On which version will it be available ( B4A/B4i/B4J?) ?
Will there be any examples ?
Thank you

Star-Dust · Jun 28, 2021

Great!! Does it also affect non-indexed variables?

Example

B4X:

Sub TicToc(Ob as object)
     Ob as B4xView.Text = "try"
End sub

B4X:

if Sub TicTac(Ob as object)
     if Ob as B4xView.Text = "try" then log("ok")
End sub

if Sub TicTec(Ob as String)
     if Ob as int = 12 then log("12")
End sub

agraham · Jun 28, 2021

I know you will have made up your mind and this might not fit your parser easily but I would find it more intuitive as

B4X:

Dim Buttons As List = Array(Button1, Button2, Button3, Button4, Button5)
Dim btn As B4XView = Buttons.Get(1)
btn.Text = "boring" 

(Buttons.Get(2) As B4XView).Text = "less boring"
Button5.Text =(Buttons.Get(2) As B4XView).Text
 Dim m As Map = CreateMap("ttt": " 123 ;lkasd  ")
Button4.Text = m.Get As String("ttt").Trim
(Root.GetView(8) As WebView).LoadURL("https://www.b4x.com") '8 is the view's index

AnandGupta · Jun 28, 2021

Alexander Stolte said:
A numbering in the designer would be very useful to find out faster the index of a view, with 20 views this is often exhausting.
0
1
2
___0
___1
___2
3
4

@Erel I would request you to consider @Alexander Stolte request too, if possible. As I too have to count them one by one.

EnriqueGonzalez · Jun 29, 2021

This is nice sintatic sugar is always welcome!

Erel · Jun 29, 2021

Star-Dust said:
Great!! Does it also affect non-indexed variables?

Currently it can only be added after methods.

Alexander Stolte said:
A numbering in the designer would be very useful to find out faster the index of a view, with 20 views this is often exhausting.

It isn't really related to this thread but it will be solved in one of the next versions.

MarcoRome said:
On which version will it be available ( B4A/B4i/B4J?) ?

The next version of each IDE.

aeric · Jun 29, 2021

Erel said:

B4X:

Dim Buttons As List = Array(Button1, Button2, Button3, Button4, Button5)
Dim btn As B4XView = Buttons.Get(1)
btn.Text = "boring"

Buttons.Get As B4XView(2).Text = "less boring"
Button5.Text = Buttons.Get As B4XView(2).Text
Dim m As Map = CreateMap("ttt": " 123 ;lkasd  ")
Button4.Text = m.Get As String("ttt").Trim
Root.GetView As WebView(8).LoadURL("https://www.b4x.com") '8 is the view's index

Wait, is this B4X version 2.0? ?

What I know is we use “As” when declaring a variable with Public/Private/Dim or when defining the return type of a function.
1. I never know we can declare something As array(x) and directly to it’s property.
2. I think I need a new introduction to .Get and .Get(x) methods.
3. SomeMap.Get As String("xxx").Trim is crazy. What is this type String(“Some Text”)?
4. Root.GetView As WebView(8).LoadURL("http...”)?
Oh no... my brain can’t process anymore!!!
Object.Method As View(i).Method(“xxx”) ?

Now, I am new to B4X. ?

Sandman · Jun 29, 2021

aeric said:
Now, I am new to B4X. ?

Yeah, I also feel very confused by this new feature.

Alexander Stolte · Jun 29, 2021

Sandman said:
Yeah, I also feel very confused by this new feature.

I think the feature will make that a little easier and more readable:

B4X:

xpnl_item_3.GetView(0).Color = BackgroundColor
xpnl_item_3.GetView(1).GetView(0).Text = Text
xpnl_item_3.GetView(1).GetView(1).GetView(0).Text = Amount & "€"
xpnl_item_3.GetView(1).GetView(1).GetView(0).Text = xpnl_item_3.GetView(1).GetView(1).GetView(0).Text.Replace(".",",")
xpnl_item_3.GetView(4).GetView(0).Text = GetItem3Count(CardType) +1

And if I have a customview, I have to declare a variable because otherwise I can't access the properties. And through the feature this is simplified, I think.

udg · Jun 29, 2021

Personally, I find that the syntax suggested by @agraham is more readable

B4X:

(Buttons.Get(2) As B4XView).Text = "less boring"

But, then, shouldn't it be

B4X:

Dim m As Map = CreateMap("ttt": " 123 ;lkasd  ")
Button4.Text = (m.Get("ttt")As String).Trim

Anyway, I'm sure that once we get used to this new feature we will love it (as it always happened in the past..)
Go B4X, go!

Sandman · Jun 29, 2021

udg said:
Personally, I find that the syntax suggested by @agraham is more readable

Yes, I find it to be a big improvement.

udg said:
But, then, shouldn't it be

Yep, it should. And that's also a big improvement in my opinion.

udg said:
Anyway, I'm sure that once we get used to this new feature we will love it

I'm not so sure, I'm really trying to like the syntax that Erel showed, but I'm not feeling it yet.

udg said:
Go B4X, go!

Agreed!

agraham · Jun 29, 2021

udg said:
But, then, shouldn't it be

Yes, I missed that one

LucaMs · Jun 29, 2021

JordiCP · Jun 29, 2021

Also will have to adapt my old brain's structure to this, but seems a good addition

Would the 'concept' be equivalent to this (incorrect) code?

B4X:

buttons.Get(2).CastTo(B4XView).Text = "less boring"

alwaysbusy · Jun 29, 2021

is this limited to Views or will this be possible too?

MyClass:

B4X:

Sub Class_Globals
    Public Name As String
End Sub

Public Sub Initialize(mName as String)
    Name = mName
End Sub

B4X:

Dim lst as List
lst.Initialize

for i = 0 to 5
    Dim cls as MyClass
    cls.Initialize("Name" & i)
    lst.Add(cls)
next

for i = 0 to lst.Size - 1
    Log(lst.Get as MyClass(i).Name)
next

My preference would've been:

B4X:

for i = 0 to lst.Size - 1
    Log((MyClass)lst.Get(i).Name)
next

But I also do like @agraham's suggestion a lot!

B4X:

for i = 0 to lst.Size - 1
    Log((lst.Get(i) As MyClass).Name)
next

EDIT: The more I look into Erels implementation, the more I start to like it! It will probably even be the easiest one to parse for e.g. BANano ?, as for JavaScript the Type is irrelevant and can just be ignored anyway:

B4X:

for (var i = 0; i < lst.length; i++)  {
    console.log(lst[i]["Name"]);
}

Alwaysbusy

agraham · Jun 29, 2021

JordiCP said:
Would the 'concept' be equivalent to this (incorrect) code?

yes.

Sandman · Jun 29, 2021

JordiCP said:
Would the 'concept' be equivalent to this (incorrect) code?

I like, nice alternative.

LucaMs · Jun 29, 2021

agraham said:

I know you will have made up your mind and this might not fit your parser easily but I would find it more intuitive as

B4X:

Dim Buttons As List = Array(Button1, Button2, Button3, Button4, Button5)
Dim btn As B4XView = Buttons.Get(1)
btn.Text = "boring"

(Buttons.Get(2) As B4XView).Text = "less boring"
Button5.Text =(Buttons.Get(2) As B4XView).Text
Dim m As Map = CreateMap("ttt": " 123 ;lkasd  ")
Button4.Text = m.Get As String("ttt").Trim
(Root.GetView(8) As WebView).LoadURL("https://www.b4x.com") '8 is the view's index

It is such a special thing that it would be even better to use square brackets (although typing these is more cumbersome).

B4X:

[Buttons.Get(2) As B4XView].Text = "less boring"

New feature - inline casting

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