Global object

[avianmanagement]

In my current VFP application I have a table dPref which holds the users preferences for the application.

Very early on in the app I call a prg which creates on object oPref attached to _screen,oApp and then issue

SCATTER NAME _SCREEN.oApp.oPref MEMO.

I could just be using SCATTER NAME _SCREEN.oPref MEMO rather than adding it to the oApp object.

Then though-out my app when I want to get the value of one of the preferences I can simply refer to the object, rather then have to make a call to a prg to use a select statement to get it.

for example:
LOCAL lnDays
lnDays = 0

IF _SCREEN.oapp.opref.nUpdateDays > 0
IF _SCREEN.oapp.opref.tLastUpdate < DATETIME()
lnDays = aim_calculate_days_between_datetimes(DATETIME(), _SCREEN.oapp.opref.tLastUpdate)
IF lnDays > _SCREEN.oapp.opref.nUpdateDays
IF YesNo_Msg('Check for updates')
aim_version_check()
aim_update_autocheck_date()
ENDIF
ENDIF
ENDIF
ENDIF

What would be the best way to do this in Lianja in:

1. Desktop apps

2. Web apps

[barrymavin]

Hi David,

In desktop you can use the same as you have however you can only SCATTER to a name. So you need to do something like this.

_screen.oApp = object()
Scatter name opref
_screen.oApp.oPref = opref

Use Lianja.public in web apps. It’s an object you can add objects/variables to.

although personally I would use Lianja.localstorage for both desktop and web.

[avianmanagement]

Thanks Barry,

In my current vfp app when the users goes into the preferences form and makes a change the code once the save has gone though redoes the object.

So In Lianaja can one do

Scatter name _screen.oApp.opref
if opref alraeasy has values?

Or similarly at the very start coukdl I issue

_screen.oApp = object()
_screen.oApp.oPref = object()

Scatter name _screen.oApp.oPref


I would dispense with the oApp reference in Lianja as it would make no sense, although I'l have to go through my existing code once it was moved over and alter the references to it, so perhaps I'l leave it as it was to save work initially.

I'll take a look at local storage.

David

[barrymavin]

Hi David

not exactly.

Scatter name oPref
_screen.oApp.oPref = opref

[avianmanagement]

Thank you

[avianmanagement]

Hi Barry,

I have done a search in the document wiki for local storage, but it does not seem to be there.


Also tried Lianja.localstorage, same result
David

[barrymavin]

Hi David

https://www.lianja.com/doc/index.php/Lianja

See localstorage on that page

[HankFay]

Hi Barry & David,

Barry's way of adding the record object to a property of the oApop object is exactly the same as VFP, FWIW.

Hank

[avianmanagement]

Hi Hank,

I'd looked at the docs and could see that this was the same as we do it now in VFP.

I was just concerned that it would not work in Web and mobile.

I've looked at the local storage option and will play with that, but it would mean altering a lot of code so I might go with the add object method for now to get more testing underway.

If I can use something like set the values in the local storage in the same code as I now do the scatter to code, which is easy to do, then something like

if nDays > Lianja.localStorage.GetItem(nUpdateDays)

I assume the data type in the localstorage are the same as the value set in them and not strings.

Barry what do you see as the advantage of the localstorage approach rather than setting the object with a scatter?

The more I play with all of this the more I see the absolute power in it, awesome.

Once I get my Xcase2Lianja code working fully then I can really started building serious stuff for conversion of my existing bird system.

David

[barrymavin]

Hi David

You should put oApp in localstorage and reference it’s members. From the console.

Lianja.localstorage.setItem(“oApp”, oApp)
? Lianja.localstorage.getItem(‘oApp’j
oApp.ndays = 10
? Lianja.localstorage.getItem(‘oApp’).ndays

_screen is a desktop thing that’s why I suggested using localstorage if you want the code to work in web/javascript OTOH you could just as easily create _screen as an object in javascript

_screen = {}
_screen.oApp = {}
_screen.oApp.ndays = 10

Hiwever, in web apps reading preferences from the server and storing in an localstorage object aims.oprefs seems better to me.



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