Hello,

I am a newbie regarding TI-Nspire Lua programming (got my CX CAS this week, immediately updated to OS v3.2).

Question:

Within a page running my Lua script, I want to store all entered values to TI.Nspire variables, before switching to another page within the same problem.
I tried to do it by using on.loseFocus() function, expecting this function will be the last one called  before leaving the script page.
On my surprise, printing out the variable values at the other page showed the old variable values, indicating the variables have not been stored.
In order the correct values are printed out, I have to re-visit the script page (there I do not edit anything, as I see there the correct values I entered the first time)
and switch back to printing page: then I see the current values.

Putting a breakpoint within on.loseFocus() function revealed that navigating away from the script page did not trigger the function.
The function has been triggered for the first time on re-visiting the script page, after on.getFocus() function made its job.

On the other hand, on.getFocus() function does its job as expected: whenever I enter the script page, I get the initial setup I defined by this function.

Do I do/understand something wrong?

Another short question just crossed my mind:
Is on.construction() function triggered each time I enter a script page, or only once, at entering the script page for the first time after I load a document?
 
Thanks for your help,
Goran

The on.construction() function is called once, namely when you open the document. For the other problem, if I understand correctly you'd want to do something like the following, right?
users switches to other page>store all entered values>reset values on the other page
The on.loseFocus() is called when user input focus is lost (I don't know when that is) May indeed be a bug like jim said, it works fine for me too. Personally if I'd wanted an event to fire when moving to a new page, I'd use on.deactivate() instead.

[edit] I also recommend having a look at the scripting api reference guide by TI http://bit.ly/P4dxnY
[edit2] Aww jim you beat me (why did I have to go fetch a drink while typing this comment )

Hi,

the same happens on the handheld, too

Here is what I do:


InputField = class()   -- a class I use to enter input variables

function InputField:init(name,x,y,init_value)
    self.name = name
    self.x = x
    self.y = y
    self.editor = D2Editor.newRichText()
    self.editor:move(x+30,y)
    self.editor:resize(100,28)
    self.editor:setBorder(1)
    self.editor:setText(var.recall(name) or (init_value or 0))  -- initially store at construction time: init_value (if defined) or 0 (if not defined) or already stored variable value (if the page is re-entered)
    var.store(name,self.editor:getText())
end

...

function InputField:storeVariable()   -- called by clients like on.loseFocus() function 
    var.store(self.name,self.editor:getText())
end

...

function on.construction()  -- create "objects"
    ...   
    field = {}
   
    field[1] = InputField('er',2,4)
    field[2] = InputField('ev',2,34)   
    ...
end

function on.getFocus()
    field[1]:setFocus()
end

function on.loseFocus()
    for i = 1, #field do
        field:storeVariable()
    end
end


Is the order of entered code (I am a newbie in Lua generally) important, too (e.g. of class definitions, variable definitions, event handlers)?

Regards,
Goran

Ah, I see your problem. D2Editors are windows of there own, the script loses focus when you select the to enter data in them.

I need to go sleep now, so I'll post a solution to this tomorrow.
Good night

Okay, here goes.

D2Editor's are special things, they have a window of there own. When selecting the D2editor, the script will already lose focus. Because of this, when you switch to another page it will not lose focus again.

Personally, I don't like to use D2editor, and have my own input objects. Anyway, let me show you how to solve this problem.
Add this line to your InputField class:
self.editor:registerFilter(editors)
Rename on.loseFocus to editors.loseFocus.
Add editors = {} before editors.loseFocus.

Try your code, it should do what you want

See D2Editor:registerFilter in the manual for some more info.

Edit, you could also add one line such as this to your InputField class:
self.editor:registerFilter{loseFocus=function () self:storeVariable() end}
I don't like to create functions during script runtime (it's slow), but since your inputs are created at script startup it shouldn't be a problem.

Actually, the utmost important thing here is to fully understand the bits and bolts of TI/Lua specific event mechanism,
(what/when/why triggers), which gives you then the real power in designing apps.

Where can one find an additional/complete documentation on that subject?

I guess you can see this article here : http://www.inspired-lua.org/2011/05/concepts-and-basics/ (basics) and http://www.inspired-lua.org/2011/05/linking-events/ (a bit more about events)
and the next ones.

More practice-oriented tutorials can be found here, then : http://compasstech.com.au/TNS_Authoring/Scripting/

Also, I can see that you have already quite some experience with programming.
Take a look at https://github.com/adriweb/EEPro-for-Nspire/ , an application I made with Adriweb. It makes use of a big toolkit I made, maybe you can find some interesting stuff in it

Hello guys,

you gave me a nice "homework" to do now

I'll enjoy study it (which will take some time).

Thanks and best regards,
Goran

Don't hesitate to ask questions, as it's quite complex ;-)