Getting (var = false) to return true?

[Joe Ruby MUDCRAP-CE]

In Rails (it's more of a Ruby question though ), I have:

def before_update
@var = get_old_var_value
end

and if get_old_var_value returns a false value it causes the update to
cancel. Is there some function that'll return true after setting the
var? Something like, oh I dunno, set_varvar, get_old_var_value).
Rails' write_attribute also seems to return the value of the var (so
false causes problems with it too). I know I can just simply do this:

def before_update
@var = get_old_var_value
true
end

But I'm just curious if there are other approaches.

Thanks,
Joe

 

[Farrel Lifson]

In Rails (it's more of a Ruby question though ), I have:

def before_update
@var = get_old_var_value
end

and if get_old_var_value returns a false value it causes the update to
cancel. Is there some function that'll return true after setting the
var? Something like, oh I dunno, set_varvar, get_old_var_value).
Rails' write_attribute also seems to return the value of the var (so
false causes problems with it too). I know I can just simply do this:

def before_update
@var = get_old_var_value
true
end

But I'm just curious if there are other approaches.

Thanks,
Joe

def before_update
@var = get_old_var_value || true
end

This returns get_old_var_value if it's not false (or nil) or true
otherwise. Is that what you need?

Farrel

 

[Farrel Lifson]

def before_update
@var = get_old_var_value || true
end

This returns get_old_var_value if it's not false (or nil) or true
otherwise. Is that what you need?

Farrel

Whoops there's a syntax error in my solution. You want
(@var = get_old_var_value) || true
otherwise you risk setting @var to true when get_old_var is false.

Farrel

 

[Joe Ruby MUDCRAP-CE]

def before_update
@var = get_old_var_value || true
end

This returns get_old_var_value if it's not false (or nil) or true
otherwise. Is that what you need?

Farrel

Nah, I need the value returned from the function to always be true. Hmm,
maybe this will work:

def before_update
(@var = get_old_var_value) || true
end

Joe

 

[Farrel Lifson]

Nah, I need the value returned from the function to always be true. Hmm,

maybe this will work:

Ruby considers any object that is not false or nil to be true.

 

[Joe Ruby MUDCRAP-CE]

Ruby considers any object that is not false or nil to be true.

Yup.

 

[Devin Mullins]

(@var = get_old_var_value) || true

Err... why is that better than
@var = get_old_var_value; true
?

Devin

 

[Robert Klemme]

Nah, I need the value returned from the function to always be true. Hmm,
maybe this will work:

def before_update
(@var = get_old_var_value) || true
end

In that case the code is too complicated. Rather use

def before_update
@var = get_old_var_value
true
end

There is no point in having "||" or "or" here.

robert