Bug? CallSub return value

[SteveTerrell]

Version 3.2

I have the following code in Main

Sub CallsubTarget As Int
    Return 1
End Sub
Sub Activity_Create(FirstTime As Boolean)
Dim i As Int

    i = CallSub(Me,"CallsubTarget")

This fails at runtime with and exception invalid double "null".

PackageAdded: package:b4a.example
** Activity (main) Create, isFirst = true **
java.lang.NumberFormatException: Invalid double: "null"
at java.lang.StringToReal.invalidReal(StringToReal.java:63)
at java.lang.StringToReal.parseDouble(StringToReal.java:269)
at java.lang.Double.parseDouble(Double.java:295)
at anywheresoftware.b4a.BA.ObjectToNumber(BA.java:585)
at b4a.example.main._activity_create(main.java:305)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.BA.raiseEvent2(BA.java:173)
at b4a.example.main.afterFirstLayout(main.java:98)
at b4a.example.main.access$100(main.java:16)
at b4a.example.main$WaitForLayout.run(main.java:76)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5017)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
at dalvik.system.NativeStart.main(Native Method)

It also does not seem to run the CallsubTarget code (or at least fails to hit a breakpoint on the return line. Is the CallsubTarget optimised out?

There is a suggestion in some documentation that the first parameter for CallSub should be the module name (Main in this case) but CallSub(Main,"CallsubTarget") gives an compile error, me seems to be accepted by the compiler though.

 

[LucaMs]

Why do you try to call a sub inside the same module using CallSub?

You can use directly:

i = CallsubTarget

 

[SteveTerrell]

Why do you try to call a sub inside the same module using CallSub?

You can use directly:

i = CallsubTarget

I realise that, this is a simplified test case for a more complex arrangement which fails in the same way.

I believe it should have worked even in this unnecessary example.

 

[LucaMs]

CallSu + CTRL + Spacebar <---- Help

To call a sub in the same module, you should provide an empty string as "component":

CallSub("", "CallsubTarget")

 

[SteveTerrell]

CallSu + CTRL + Spacebar <---- Help

To call a sub in the same module, you should provide an empty string as "component":

CallSub("", "CallsubTarget")

If you try it you will find it fails in the same way. The real problem appears to be the return object.

Even with Me replaced by "" it still does not hit a breakpoint in CallsubTarget

I may be wrong but i think the empty string is an option which can be used.

 

[LucaMs]

I tried it (now) and it works, but I have the v. 3.00

 

[SteveTerrell]

I tried it (now) and it works, but I have the v. 3.00

Thanks, looks like it might need some input from Anywhere.

 

[Erel]

The Activity is considered paused until Activity_Create ends therefore the CallSub call is not triggered (you cannot use CallSub to raise a sub in a paused activity). You should move this code to Activity_Resume.

This was always the behavior of CallSub. It hasn't changed in v3.20.

 

[SteveTerrell]

Yes that fixed it, thanks.

The invalid double "null" fault report is a bit unhelpful, could the (wrong usage) situation be better detected and reported?

 

[Erel]

The null error happens because CallSub returns null in this case. I will add a warning log for this case.