Ugly Code?

[Dan]

Hi,

I'm new to ruby. I have a calendar on a web page and need to add
links to move to the next and previous months while keeping the
selected day within the month constant where possible. Here's what I
wrote to determine the next month, but it feels verbose and not very
ruby-like. Suggestions?

def get_next_month(d)
month = d.month
year = d.year
day = d.day

if month == 12
month = 1
year += 1
else
month +=1
end

d_out = nil
while !d_out
begin
d_out = Date.civil(year, month, day)
rescue
day -= 1
end
end

d_out

end

 

[rhild]

Dan,

How about this:

def next_month(d)
d >> 1
end

 

[James Herdman]

def get_next_month(d)

month = d.month
year = d.year
day = d.day

if month == 12
month = 1
year += 1
else
month +=1
end

d_out = nil
while !d_out
begin
d_out = Date.civil(year, month, day)
rescue
day -= 1
end
end
d_out
end

I'm a little confused by your code. Some questions:

1. What is the parameter "d"? What is it's role in the overall picture?
2. a. What is the purpose of the while() loop? I can see how d_out
is being set, but are you expecting some sort of problem that would
require you to keep trying to find a new day?
b. Won't this while() loop only run once? d_out should only ever
be nil once, right?

James H.

 

[ChrisH]

Wouldn't this suffice?:

def get_next_month(d)
return d>>1
end


Cheers

 

[ChrisH]

Actually, after RTFMing a bit, I see that Date#next_month(n=1) does
just that (see
http://ruby-doc.org/stdlib/libdoc/date/rdoc/classes/Date.html#M000354)

cheers

 

[Dan]

Firstly, thanks for all the responses! I guess I should have been more
clear in my initial post. d is a Date object. The goal of the
function is to return a Date object for the same day in the next month.
For example, 2006-03-25 would become 2006-04-25. The while loop is
there to handle dates like 2006-01-31, which would need to become
2006-02-28 since there is no 31st in Feb.

Dan

 

[ChrisH]

Firstly, thanks for all the responses! I guess I should have been more
clear in my initial post. d is a Date object. The goal of the
function is to return a Date object for the same day in the next month.
For example, 2006-03-25 would become 2006-04-25. The while loop is
there to handle dates like 2006-01-31, which would need to become
2006-02-28 since there is no 31st in Feb.

Dan

If you look at the docs you'll see that next_month (or >>) already
adjust for months with differing end days.

One caveat, I guess next_month is a new method as it doesn't exist in
my install. >> works as described, and you can implement next_month,
or just gert the lates Date lib.

Cheers

 

[James Herdman]

If you look at the docs you'll see that next_month (or >>) already
adjust for months with differing end days.

One caveat, I guess next_month is a new method as it doesn't exist in
my install. >> works as described, and you can implement next_month,
or just gert the lates Date lib.

Cheers

I have Date#>> in my install -- Ruby 1.8.4. It definitely solves the
problem =)

James H.

 

[Dan]

Thanks Chris. I was being dense and automatically translating >> as +.
Being able to reduce my code to one line rocks!

Dan