Build 3x3 table from one array

ruby-talk
1

I am new to ruby and still haven't got my mind around iterators although
I think they are really cool.

I am stuck trying to figure out how to take an array of data and
dynamically build a 3x3 html table from it without standard for loops.

Here is the code in JavaScript:

var MAX_ROW = 3;
var MAX_COL = 3;
var nIdx = 0;

print("<table>");
for (var r = 0; nIdx < aList.length && r < MAX_ROW; r++)
{
  print("<tr>");
  for (var c = 0; nIdx < aList.length && c < MAX_COL; c++)
  {
    print("<td>");

    print(aList[nIdx].name);
    nIdx++;

    print("</td>");
  } // cols
  print("</tr>");
} // rows
print("</table>");

Can someone point me in the right direction for how to do this. I found
each_index but still was at a loss.

Thanks for the help.
forest

···

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2

forest wrote:

I am stuck trying to figure out how to take an array of data and
dynamically build a 3x3 html table from it without standard for loops.

Here is the code in JavaScript:

*snip*

Can someone point me in the right direction for how to do this. I found
each_index but still was at a loss.

Without giving it a lot of thought, I'd do something to the effect of:

rows = [
    [ 'col1', 'col2', 'col3' ],
    [ 'cOl1', 'Col2', 'col3' ],
    [ 'col1', 'COL2', 'COl3' ],
]

output = ''

output << '<table>'
rows.each do |row|
    output << '<tr>'
    row.each do |col|
        output << "<td>#{col}</td>"
    end
    output << '</tr>'
end
output << '</table>'

puts output

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3

I am stuck trying to figure out how to take an array of data and
dynamically build a 3x3 html table from it without standard for loops.

Here's one idea:

>> data = (1..9).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
>> require "enumerator"
=> true
>> puts "<table>"
<table>
=> nil
>> data.each_slice(3) do |row|
?> puts " <tr>"
>> row.each { |cell| puts " <td>#{cell}</td>" }
>> puts " </tr>"
>> end
   <tr>
     <td>1</td>
     <td>2</td>
     <td>3</td>
   </tr>
   <tr>
     <td>4</td>
     <td>5</td>
     <td>6</td>
   </tr>
   <tr>
     <td>7</td>
     <td>8</td>
     <td>9</td>
   </tr>
=> nil
>> puts "</table>"
</table>
=> nil

Hope that helps.

James Edward Gray II

···

On Mar 16, 2006, at 11:29 AM, forest wrote:

4

Pistos Christou wrote:

forest wrote:
> I am stuck trying to figure out how to take an array of data and
> dynamically build a 3x3 html table from it without standard for loops.
>
> Here is the code in JavaScript:
*snip*
> Can someone point me in the right direction for how to do this. I found
> each_index but still was at a loss.

puts %w(1 2 3 4 5 6 7 8 9).map{|x| "<td>" + x + "</td>" }.
  join.gsub(/(<td.*?\/td>){3}/,"<tr>\n \\&\n</tr>\n")

5

Thanks all. The each_slice solution I think will work the best for my
scenario. I really appreciate the help.

forest

···

>> data = (1..9).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9]
>> require "enumerator"
=> true
>> puts "<table>"
<table>
=> nil
>> data.each_slice(3) do |row|
?> puts " <tr>"
>> row.each { |cell| puts " <td>#{cell}</td>" }
>> puts " </tr>"
>> end

Hope that helps.

James Edward Gray II

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6

>> require "enumerator"

Is this standard library?

I tried 'ri Enumerator' to learn more, but it just comes back talking
about SyncEnumerator, which is something else. (Trying the lowercase
'enumerator' didn't work at all.)

7

Yes, enumerator is part of the standard library. Go to http://ruby-doc.org/stdlib/ and find enumerator (right after English) in the left frame if ri isn't helping.

Tim

···

On Mar 16, 2006, at 1:10 PM, Matthew Moss wrote:

require "enumerator"

Is this standard library?

I tried 'ri Enumerator' to learn more, but it just comes back talking
about SyncEnumerator, which is something else. (Trying the lowercase
'enumerator' didn't work at all.)

8

I wrote next function (maybe need to be rewritten to method for Array
cass) -
  def array_to_table(arr, width)
    data = "<table>"
    arr.each_slice(width) do |row|
      data << "<tr>"
      row.each do |elem|
        data << ("<td>" + yield(elem) + "</td>")
      end
      data << "</tr>"
    end
    data << "</table>"
  end

Using -
<%= array_to_table(User.find(:all), 3) {|user| "<div
id='user_div'>#{user.name}</div>"} %>

···

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