From: Todd Benson <caduceass@...>
Date: 2008-03-04T04:14:20+09:00
Subject: Re: making a monthly calendar...

On Mon, Mar 3, 2008 at 1:02 PM, Todd Benson <caduceass@gmail.com> wrote:
>
> On Mon, Mar 3, 2008 at 2:05 AM, Mikkel Bruun <mikkel@helenius.dk> wrote:
>  > So I ended up with:
>  >
>  >  def calendar_view
>  >     firstday = days[0] #all days in month
>  >     offset = firstday.wday-1
>  >     boxes =Array.new(5*7) # the viewport
>  >     i=0
>  >     #this month from wday of firstday
>  >     offset.upto(days.length+offset){boxes[offset+i]=days[i];i=i+1}
>  >     i=0
>  >     #pad with previous
>  >     1.upto(offset){boxes[i]=previous.days[-offset+i];i=i+1}
>  >     i=0
>  >     #pad with next...
>  >     (offset+days.length).upto(boxes.length){boxes[days.length+i+offset]=next_month.days[i];i=i+1}
>  >      return boxes
>  >   end
>  >
>  >  I show this in a rails app using array.groups_of(7) which chops the
>  >  boxes array into parts of 7
>  >
>  >  which works ok...untill i hit june 08....where the first week starts
>  >  with jun 2nd...
>  >
>  >  How are your algorithms working??
>
>  You can use my code (with the correction in my last post), and omit
>  the each_slice part (you do want one big array right?).
>
>  To explain what I was doing in a different way,  I build three arrays
>  with the correct number of days in each, centered around the current
>  month (that's why I add -1, 0, and 1 to the current month number).  I
>  use (didn't with the first code, sorry) the first day of the current
>  month as the offset.  I build ranges after I get the month numbers,
>  then build arrays off those ranges.  So I have a single array of three
>  arrays.  When I #pop off the first array and #unshift _onto_ the
>  second array, it moves the last day number of the previous month array
>  onto the first day of the current month array; sort of what you are
>  doing by hand.  I do this offset number of times using the #times
>  method.  Then I flatten (the weird current month array rolled into the
>  next month array -- the use of the 1..2 range).  I used each_slice for
>  display, but, obviously, you won't have to do that, because you have
>  #groups_of.  Just flatten and slice.
>
>  In any case, google calendar uses a 7 x 7 grid.  I would recommend at
>  least a 7 x 6 grid for reasons I pointed out earlier.  When you
>  display March, for example, you will only go up to 29 with 7 x 5.
>
>  Here's the script code without the previous comments, and
>  surreptitiously using a 7 x 6 grid (I still would code this
>  differently by separating out into methods, and also probably a Month
>  and/or Calendar class)...
>
>  today = Date.today #use whatever date you want
>
> offset = Date.new(today.year, today.month, 1).wday
>  # ^^^^^^ that was the line I screwed up at first
>  months_of_concern = (-1..1).inject([]) {|a, i| a << (today.month + i)}
>
> month_ranges = months_of_concern.map {|month| 1..Date.new( today.year,
>  month, -1 ).day}

That's one line and suppose to be today.month following today.year.

>  day_sets = month_ranges.map {|i| i.map}
>
> offset.times {day_sets[1].unshift day_sets[0].pop}
>  p day_sets[1..2].flatten.slice(0..42)
>

Todd