Android Tutorial [B4X] Features that Erel recommends to avoid

Many things have changed in B4X and also in the underlying platforms. I will try to list here all kinds of (old) features that have better alternatives.
B4X is backward compatible so these features still work. The recommendations are more relevant for new projects or when implementing new features.

1. (B4A) ListView -> xCustomListView:
   ListView is difficult to work with and cannot be customized. It is also not cross platform.
   
   
2. (B4i) TableView -> xCustomListView:
   Same as above.
   
   
3. CustomListView module -> xCustomListView library:
   Using the module will break other libraries.
   
   
4. Sub JobDone -> Wait For (j) JobDone:
   [B4X] OkHttpUtils2 with Wait For
   
   
5. Sub Smtp_MessageSent (and others) -> Wait For ...:
   https://www.b4x.com/android/forum/threads/b4x-net-library-ftp-smtp-pop-with-wait-for.84821/#content
   
   
6. DoEvents / Msgbox -> DoEvents deprecated and async dialogs (msgbox)
   
   
7. All kinds of custom dialogs -> B4XDialogs: B4XDialogs are cross platform and are fully customizable:
   [B4X] Share your B4XDialog + templates theming code
   
   
8. File.DirDefaultExternal -> RuntimePermissions.GetSafeDirDefaultExternal
   Truth is that you shouldn't use both of them and use XUI.DefaultFolder instead.
   https://www.b4x.com/android/forum/threads/67689/#content
   
   
9. File.DirRootExternal -> ContentChooser / SaveAs
   https://www.b4x.com/android/forum/threads/132731/#content
   
   
10. File.DirInternal / DirCache / DirLibrary / DirTemp / DirData / DirDefaultExternal / GetSafeDirDefaultExternal -> XUI.DefaultFolder
    
    
11. Round2 -> NumberFormat, B4XFormatter:
    Most usages of Round2 are to format numbers. Modifying the number is not the correct way.
    
    
12. TextReader / TextWriter with network streams -> AsyncStreams:
    Trying to implement network communication on the main thread will always result in bad results.
    
    
13. TextReader / TextWriter -> File.ReadString / ReadList:
    Two exceptions - non-UTF8 files or huge files (more relevant to B4J).
    
    
14. Activities -> B4XPages:
    This is a big change and it is the most important one. It is hard to explain how much simpler things are with B4XPages. The more complex the project the more important it is to use B4XPages. This is also true when building non-cross platform projects. [B4X] [B4XPages] What exactly does it solve?
    
    
15. Platform specific API -> Cross platform API:
    This is of course relevant when there is a cross platform API. Some developers have a misconception that the cross platform features have drawbacks compared to the platform specific API.
    • Node / Pane / Button / ... -> B4XView
    • Canvas -> B4XCanvas
    • All kinds of platform specific custom views -> cross platform custom views (such as XUI Views).
    • EditText / TextField / TextArea / TextView -> B4XFloatTextField
    • fx (and others) -> XUI
    • MsgboxAsync / Msgbox2Async / (B4i) Msgbox -> XUI.MsgboxAsync / XUI.Msgbox2Async
16. CallSubDelayed to signal a completion of a resumable sub -> As ResumableSub:
    [B4X] Resumable subs that return values (ResumableSub)
    
    
17. CallSubDelayed / CallSubPlus to do something a bit later -> Sleep(x):
    There are many other useful usages for CallSubDelayed.
    
    
18. Multiple layout variants -> anchors + designer script:
    When Android was first released there were very few screen sizes. This is no longer the case. You should build flexible layouts that fill any screen size. It is easier to do with anchors + designer script. It is difficult to maintain multiple variants.
    
    
19. Building the layout programmatically -> using the designer when possible:
    If you are only developing with B4A then building the layout programmatically is a mistake but not a huge one.
    B4J and B4i handle screen resizes differently and it is much more difficult to handle the changes programmatically (there is video tutorial about it).
    Most custom views can only be added with the designer (there are workarounds that allow adding them programmatically).
    It is very simple to copy and paste designer layouts between different platforms and projects.
    
    
20. Multiline strings with concatenation -> smart strings:
    [B4X] Smart String Literal
    
    
21. (SQL) Cursor -> ResultSet:
    ResultSet is cross platform and is also a bit simpler to use.
    
    
22. ExecQuery (non-parameterized queries) -> ExecQuery2:
    Making non-parameterized queries is really unacceptable. See point #5 for more information: https://www.b4x.com/android/forum/t...ommon-mistakes-and-other-tips.116651/#content
    It is also true for ExecNonQuery.
    
    
23. ExecQuerySingleResult when it is possible that there are no results -> ExecQuery2
    This is a historic design mistake. Nulls and Strings don't go together. If there is a possibility that ExecQuerySingleResult will return no results (=Null) then don't use it and use ExecQuery2 instead.
    
    
24. Downloading / making http requests with any other library or source other than OkHttpUtils2 (=iHttpUtils2) -> OkHttpUtils2
    OkHttpUtils2 is very powerful and can be extended in many ways, without modifying the source. It is also very simple to use.
    
    
25. Shared modules folder -> referenced modules
    The shared modules feature was useful in the early days of B4X. With the introduction of referenced modules, there is no good reason to use it. Referenced modules cover the same use cases and more.
    
    
26. VideoView -> ExoPlayer
    ExoPlayer is much more powerful and more customizable.
    
    
27. StartServiceAt / StartServiceAtExact -> StartReceiverAt / Exact
    With a few exceptions, it is no longer possible to start services in the background.

Related thread: [B4X] "Code Smells" - common mistakes and other tips
More to come.

 

[Peter Simpson]

An excellent list of what to avoid Erel, I think that I'll store this URL for reference as I always forget one or two things.

Thank you...

 

[Sandman]

So good list. This thread deserves to be sticky.

 

[jahswant]

You should also avoid old threads : Better create a new one.

 

[Mashiane]

Thanks for the list, however wouldn't it be better if for example on each point you put across you also include the alternative to use.

For example on this line,

• (B4A) ListView -> xCustomListView: ListView is difficult to work with and cannot be customized. It is also not cross platform.

I don't seem to pick the recommended alternative.

Thanks.

 

[LucaMs]

Thanks for the list, however wouldn't it be better if for example on each point you put across you also include the alternative to use.

For example on this line,

• (B4A) ListView -> xCustomListView: ListView is difficult to work with and cannot be customized. It is also not cross platform.

I don't seem to pick the recommended alternative.

Thanks.

I did not understand the matter; the alternative is indicated after the arrow, right? (xCustomListView there)

 

[Erel]

xCustomListView is the recommended alternative:

[not recommended] -> [recommended]

 

[LucaMs]

Probably a table like Excel would be more readable:

Language	Not recommended	Recommended	Reason
B4A	ListView	xCustomListView	ListView is difficult to work with and cannot be customized. It is also not cross platform.
B4i	TableView	xCustomListView	same as above
All	CustomListView module	xCustomListView library	Using the module will break other libraries

 

[klaus]

Added in the B4X Basic language booklet for the next edition.

 

[Erel]

Probably a table like Excel would be more readable:

Tables are not supported in the forum. I've improved the formatting.

 

[Sandman]

Tables are not supported in the forum.

Sure they are. The key is to manually enter the tags, as we don't have a button for it in the UI. Here's the syntax: https://www.bbcode.org/examples/?id=14

 

[Erel]

Now I need a different excuse... Maybe next time.

 

[Sandman]

Maybe next time

Just give me edit rights for the top post in this thread and I'll whip it up for you.

 

[LucaMs]

Tables are not supported in the forum. I've improved the formatting.

In fact, I don't know how they can be inserted: copying and pasting from Excel is possible.

 

[Erel]

I've added three points to the list.

 

[LucaMs]

CallSubDelayed / CallSubPlus to do something a bit later -> Sleep(x)

Just when you want "to do something a bit later", since in B4J CallSubDelayed is useful for a different purpose ("delegate" the job. Erel, you are able to explain this much better than me ?)

 

[Mahares]

Although there is a little bit of overlap between this thread and 'Code Smells' thread, these two below items should probably be also mentioned here due to their widespread use:
Cursor -> Resultset
Non-parameterized query -> parameterized query
To make it stand out, you may want to make bold the replacement feature.

 

[Jeffrey Cameron]

There's enough of an informational divergence here (as well as outdated solutions based on old API information) have you considered starting a new "B4X(Pages)" forum not related to this one, keeping the same forum structure but starting with no posts and the current API?

 

[Erel]

No. Things change all the time. Important examples are being updated.

 

[Jeffrey Cameron]

No. Things change all the time. Important examples are being updated.

I wasn't implying they don't, LOL, you move too fast for this old turtle to keep up!

I was pointing out that when searching the forum researching a problem, I tend to come across all kinds of solutions that are either no longer applicable due to API changes or old examples that have been "updated" to B4XPages/Views. Unfortunately for me it seems that it's usually after I implement the old example and find it doesn't work or stumble across the newer implementation searching something else. Perhaps I'm just incompetent, I'm not ruling that out