Android Question Resumable functions

LucaMs · Nov 23, 2017

I'm trying to create a FUNCTION like:

B4X:

Sub DownloadFile(FileName As String) As ResumableSub
    Dim Result As Boolean

    Dim HJob As Httpjob
    ' ...
    ' ...
    Wait For (HJob) Jobdone(jobResult As HttpJob)
    If jobResult.Success...
    '...
    Result = ---
    ' ...
    Result = ---
    '...

    Return Result
End Sub

but I get this exception:
java.lang.RuntimeException: Cannot parse: (RemoteResumableSub) anywheresoftware.b4a.shell.DebugResumableSub$RemoteResumableSub@21f819e0 as boolean

It seems (to me) that "Wait For", returns the control to the calling code also returning an Httpjob object (jobResult) to it (in this case), while the function would like to return a boolean.

How should I create a function like this?

Thank you

Erel · Nov 23, 2017

Check this tutorial: [B4X] Resumable subs that return values (ResumableSub)

LucaMs · Nov 23, 2017

Erel said:
Check this tutorial: [B4X] Resumable subs that return values (ResumableSub)

I know it but it is not enough to answer my question.

It is about "resumable functions" but if the function contains a... my first post explains well enough, I think.

Anyway, I fear I have to duplicate my code, instead of creating that kind of function.

Erel · Nov 23, 2017

I'm afraid that you haven't read it carefully. Can you post the code that calls this sub?

LucaMs · Nov 23, 2017

Erel said:
Can you post the code that calls this sub?

Synthetically, what I think may be relevant:

B4X:

Sub ChooseLanguage_Click ' <--- resumable

   Dim cd As CustomLayoutDialog
   cd.ShowAsync("Choose language"
   Wait For Dialog_Ready (DialogPanel As Panel)
   
   Wait For CLVDialog_ItemClick (Index As Int, Value As Object)


    If DownloadDB(DBFileToDownload) Then ' DownloadDB should be a resumable function


End Sub

Erel · Nov 23, 2017

All that I can say is that you should go over the tutorial. It explains how resumable subs that return values should be called.

LucaMs · Nov 23, 2017

Erel said:
All that I can say is that you should go over the tutorial. It explains how resumable subs that return values should be called.

And again I must answer that I know that tutorial; evidently I am a fool, unable to apply those rules to this situation.
I take it and I stop programming.

THANK YOU !!!

Erel · Nov 23, 2017

See step #3 from the tutorial:

The steps required are:

1. Add As ResumableSub to the resumable sub signature.
2. Call Return with the value you like to return.
3. In the calling sub, call the resumable sub with Wait For (<sub here>) Complete (Result As <matching type>)

Example from the tutorial:

B4X:

Sub Button1_Click
   Wait For(Sum(1, 2)) Complete (Result As Int) '<---------------------------------
   Log("result: " & Result)
   Log("after sum")
End Sub

Sub Sum(a As Int, b As Int) As ResumableSub
   Sleep(100)
   Log(a + b)
   Return a + b
End Sub

LucaMs · Nov 23, 2017

I know!!!

I answered to a question about Resumable subs which return values, pointing to your turorial!

My question is like if you wanted to insert an httpjob, with a wait for, in your sub Sum.

Forse io dovrei scrivere in italiano, affinché si capisca

Erel · Nov 23, 2017

It doesn't matter what you do inside the resumable sub.

Your mistake is that you try to call DownloadFile as if it is a regular sub. You should instead call it like this:

B4X:

Wait For (DownloadFile("http://...")) Complete (Result As Boolean)
If Result Then
 Log("File downloaded successfully")
End If

LucaMs · Nov 23, 2017

Yes, you code is correct, I know, but there are differences in my code, to my intentions.

I try to explaing using the example (from your tutorial) you posted in #8.

B4X:

Sub Button1_Click
   Wait For(Sum(1, 2)) Complete (Result As Int) '<---------------------------------
   Log("result: " & Result)
   Log("after sum")
End Sub

Sub Sum(a As Int, b As Int) As ResumableSub
   Sleep(100)

   Wait for http job to get Factor from Internet
   Return (a + b) * Factor
End Sub

I changed something, as you can see (pseudo-code). If you did something like that, you would get the exception I posted in my first post.

Erel · Nov 23, 2017

LucaMs said:
If you did something like that, you would get the exception I posted in my first post.

Please upload a small project that demonstrates it.

LucaMs · Nov 23, 2017

Erel said:
Please upload a small project that demonstrates it.

I can't, because... it works, without exceptions .

Trying to discover the error in my code!

Thank you.

LucaMs · Nov 23, 2017

That's exactly what I was saying, Erel: that is, I'm stupid!

In this line:

LucaMs said:
If DownloadDB(DBFileToDownload) Then ' DownloadDB should be a resumable function

I pretended to receive the result, even though I know how to use a resumable that returns a result.

The problem is that I'm stressed, especially this period; or... I'm really stupid (this is much more likely ).

I'm sorry for all this .

Thank you, Erel.

Android Question Resumable functions

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

Erel

B4X founder

LucaMs

Expert

LucaMs

Expert

Similar Threads

Android Question Resumable functions

Expert

B4X founder

Expert

B4X founder

Expert

B4X founder

Expert

B4X founder

Expert

B4X founder

Expert

B4X founder

Expert

Expert

Similar Threads

Privacy & Transparency

Privacy & Transparency