Android Question B4XPages scope of variables

Phayao

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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
 
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Phayao

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

Thank you
 
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mangojack

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Phayao said:
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 ?
Click to expand...

Alexander Stolte said:
In the main module, even without B4XPages the sql object should be placed there.
Click to expand...


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 ?
 
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Phayao

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Thanks all for helping out !

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

B4X: 
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.
 
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Erel

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

Alexander Stolte said:
In the main module, even without B4XPages the sql object should be placed there.
Click to expand...
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?
 
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Phayao

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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
 
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