MAAccessor

Hi ...

I don't really see how the different MAaccesor work... as I'm always
using MASelector...

For instance, what could be the use of MADictionnaryAccesor ?

MAVariableAccesor ? (used in MADescription class)

MAContainerAccessor ?

...

Are they always linked to real instance variables (created) ?



Thanks

Cédrick
I

_______________________________________________
SmallWiki, Magritte, Pier and Related Tools ...
https://www.iam.unibe.ch/mailman/listinfo/smallwiki

_______________________________________________
Smallwiki mailing list
[hidden email]
http://impara.de/mailman/listinfo/smallwiki

Cédrick Béler a écrit :
> Hi ...
>
> I don't really see how the different MAaccesor work... as I'm always
> using MASelector...

Do you use last Magritte version ? There is comments in the MAAccessor
classes now.

> For instance, what could be the use of MADictionnaryAccesor ?

This one expects a dictionary as the model and a key to create the
accessor. #read: is equivalent to #at: on dictionaries while #write:to:
is equivalent to #at:put:.

> MAVariableAccesor ? (used in MADescription class)

MAVariableAccessor is used only as a convenience constructor in
MADescription in fact. It access directly a variable of the model passed
to #write:to: or #read. You'd better use MASelectorAccessor or
MAAutoSelectorAccessor.

> MAContainerAccessor ?

This one is not supposed to write. And when used for reading, it answers
the model given as the argument.

> Are they always linked to real instance variables (created) ?

Not at all. Only MAVariableAccessor use instance variables directly.
MASelectorAccessor does not require a variable, it can store in a
database for example or something else that fit your needs.

--
Damien Cassou

CSS3 :  "On passe au  HSL, plus intuitif  et moins orienté CRT  que le
RGB. Il y a du HSLA". Et en plus, ça veut dire quelque chose (au moins
pour l'auteur) !

_______________________________________________
SmallWiki, Magritte, Pier and Related Tools ...
https://www.iam.unibe.ch/mailman/listinfo/smallwiki

_______________________________________________
Smallwiki mailing list
[hidden email]
http://impara.de/mailman/listinfo/smallwiki

> I don't really see how the different MAaccesor work... as I'm always
> using MASelector...

Don't worry, this is fine. It is probably the accessor to be used in  
95% of the cases.

> For instance, what could be the use of MADictionnaryAccesor ?

If you have a dictionaries with your values ... e.g. a property  
dictionary with different key and value pairs.

> MAVariableAccesor ? (used in MADescription class)

I've never used it, but it is cool to have ;-)

> MAContainerAccessor ?

It is used internally by Magritte. It is the same as:

        MASelectorAccessor read: #yourself
        (this is also read-only)

> Are they always linked to real instance variables (created) ?

No, as Damien said they can be dynamically calculated, fetched from a  
database, dispatched to other objects, etc.

Cheers,
Lukas

--
Lukas Renggli
http://www.lukas-renggli.ch



_______________________________________________
SmallWiki, Magritte, Pier and Related Tools ...
https://www.iam.unibe.ch/mailman/listinfo/smallwiki
_______________________________________________
Smallwiki mailing list
[hidden email]
http://impara.de/mailman/listinfo/smallwiki

Hi :)

For instance, what could be the use of MADictionnaryAccesor ?
    

If you have a dictionaries with your values ... e.g. a property  
dictionary with different key and value pairs.
  

Actually, I think I might need one so I m trying to understand how it works.
I'd like to do somethink like that:

experience
    event:= 'avalanche'.
    temperature := #( #value->25  #analyses-> #(1 0) )      
    activity := #(#value->anActivity    #analyses-> #(1 0.8) )
    ...  

It's a way to add analyses element to an experience (on their attributes)

I'd like to use a MADictionaryAccesor to manage to build description to have a simple editor and viewer "like if" my experience object was:

experience
    event:= 'avalanche'.
    temperature := 25     
    activity := anActivity

but  also, the same one in readonly + editor on analyses element (2 text fields)

I tryed a bit today but I'll look at that deeper tomorow. Is it a case where MADictionaryAccessor could be useful ? (I hope I'm clear enough ;))

Are they always linked to real instance variables (created) ?
    

No, as Damien said they can be dynamically calculated, fetched from a  
database, dispatched to other objects, etc.

  

and so they can be seen as extra-information on an object defined in squeak ?


see you :)

Cédrick


_______________________________________________
SmallWiki, Magritte, Pier and Related Tools ...
https://www.iam.unibe.ch/mailman/listinfo/smallwiki
_______________________________________________
Smallwiki mailing list
[hidden email]
http://impara.de/mailman/listinfo/smallwiki