[Seaside] Collecting form input

[Philippe Marschall]

2008/10/4, Sebastian Nozzi <sebnozzi at googlemail.com>:
> Hello all,
>
> when trying to collect the values from a form, I run into a problem.
>
> Let's suppose I write a form to add a new user (user name), together
> with an user-type.
>
> I was trying to do something like this:
>
> | newName newType |
> html
>        form: [html textInput value: 'type name here';
>                        callback: [:name | newName := name].
>                html select list: userTypes;
>                        callback: [:userType | newType := userType];
>                        labels: [:userType | userType asString].
>                html submitButton
>                        callback: [self addUserNamed: newName withType:
> newType];
>                         value: 'Add New User']
>
> But it didn't work. Inside of the callback-block of the submit-button,
> both variables were nil.
> I searched a little in Internet and the cause seems that when the
> block is created, it binds to the value of both variables, which at
> that time WERE nil.
>
> Is this correct? I think I read that the new Squeak versions will
> correct this "problem"? (something like a new block-compiler...)
>
> Anyway, I reverted to following solution:
> (which works)
>
> | params |
>
> params := Dictionary new.
> html
>        form: [html textInput value: 'type name here';
>                        callback: [:name | params at: #name put: name].
>                html select list: userTypes;
>                        callback: [:userType | params at: #type put:
> userType];
>                        labels: [:userType | userType asString].
>                html submitButton
>                        callback: [self addUserNamed: (params at:#name)
> withType: (params at:#type)];
>                         value: 'Add New User']
>
> Did I do the right thing? Or is there a better way?

You could also use ValueHolders but that gets quite ugly. I'd use
instance variables and split it up.

Cheers
Philippe