Android Question B4XPages scope of variables

[Phayao]

Hello,

I am playing with the new concept of pages and got stuck using sql databases.
1) declaring a sql db and initializing in the starter or main page gives me the error that the db cannot be opened (despite using android.permission.WRITE_EXTERNAL_STORAGE)
2) initializing the db in the B4Xresults gives the error java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method)

My question: where should i define and initialize a sql database that can be accessible by all pages ?

Thanks a lot in advance !

Chris

 

[Phayao]

Thank you, but where to initialize ? Also in the main module, and where there ?
Before or after pm.initialize ?

Thank you

 

[klaus]

You can also Dim the SQL in the B4XMainPage, Public SQL1 As SQL, and initialize it in the B4XPage_Created routine.
And access it in other modules with: B4XPages.MainPage.SQL1.

 

[mangojack]

declaring a sql db and initializing in the starter or main page gives me the error that the db cannot be opened ....

... where should i define and initialize a sql database that can be accessible by all pages ?

In the main module, even without B4XPages the sql object should be placed there.

I have only had a quick play with B4XPages ... but previously in B4A , it was recommended to declare and initialize SQL (and other objects) in the starter service.

I can understand the thinking declaring SQL object in B4XMainPage etc, in a Cross Platform project (and maybe doing away with the starter service to reduce some code.)

But in a solely B4A app (with B4XPages) , would it not still be the recommended way to go ? (using Starter Service for declaring public objects etc.)


I don't know why @Phayao encountered the errors but surely if the Object is Declared and Called correctly all should be good .... No ?

 

[Phayao]

Thanks all for helping out !

In this special case the problem was that the runtime permission was missing prior to initialze SQL:

Sub Activity_Create(FirstTime As Boolean)

    Dim rp As RuntimePermissions
    
    ' check write permissions BEFORE sql.ini
    rp.CheckAndRequest(rp.PERMISSION_WRITE_EXTERNAL_STORAGE)
    wait for Activity_PermissionResult(Permision As String, Result As Boolean)
    
    SQL1.Initialize(DBDir,DBFile,False)
    Dim pm As B4XPagesManager
    pm.Initialize(Activity)

Therefore the initialization of the sql did not work.

 

[Erel]

Don't write anything in the Main module. You don't need to.

In the main module, even without B4XPages the sql object should be placed there.

Wrong answer.

A good place for it is B4XMainPage. You should handle the runtime permission in B4XMainPage. Just change Activity with B4XPage.

BTW, why aren't you storing the database in File.DirInternal or RP.GetSafeDirDefaultExternal?

 

[Phayao]

Thanks a lot !

I store the database external, so it can be backuped manually - but maybe your solution is better for safety reasons - thanks again !

Chris