Aligning decimal points in HTML

Question

I have a table containing decimal numbers in one column. I\'m looking to align them in a manner similar to a word processor\'s \"decimal tab\" feature, so that all the poin

Answer 1

The function made by Krijn Hoetmer interferes with prettyPhoto ( http://www.no-margin-for-errors.com/projects/prettyphoto-jquery-lightbox-clone/ ) so I made a jQuery version. The currency part is removed as it should be made dynamic instead of replacing strings based on predefined currencies.

Needed is the empty function from phpjs: http://phpjs.org/functions/empty:392 .

The jQuery used, is version 1.6.

/* This function will align table columns on the char if in the col from the 
 * colgroup has the property 'align="char"' and a attribute 'char'. The alignment
 * is done on the first occurence of the specified char.
 * 
 * The function is inspired from:
 * 
 * http://krijnhoetmer.nl/stuff/javascript/table-align-char/
 * http://stackoverflow.com/questions/1363239/aligning-decimal-points-in-html
 */
function alignNumbers()
{
  var table; /* This will store the table currently working on . */
  var i = 0; /* Every column can have it's own width, the counter makes the class name unique. */

  /* Get all tables for which the alignment fix must be done. 
   *
   * Note: this could even be further optimized by just looking for tables where
   * there is a a col with 'align="char"'. 
   */
  $('table.fix-align-char').each(function(index)
  {
    table = $(this);

    /* All table columns are fetched to have a correct index, without it it's
     * hard to get the correct table cells.
     */
    $(this).find('col').each(function(index)
    {
      /* Only those table cells are changed for which the alignment is set to
       * char and a char is given.
       */
      if ($(this).prop('align') == 'char' && !empty($(this).attr('char')))
      {
        /* Variables for storing the width for the left and right part (in pixels). */
        var left_width = 0, right_width = 0;
        var col, left_part, right_part, parts, new_html;
        i++; /* Increase the counter since we are working on a new column. */
        col = $(this);

        /* For the col index + 1 (nth-child starts counting at 1), find the table
         * cells in the current table.
         */
        table.find('> tbody > tr > td:nth-child('+ (index + 1) +')').each(function(index)
        {
          /* Split the html on the specified char. */
          parts = $(this).html().split(col.attr('char'));
          new_html = '';


          /* The first element is always the left part. The remaining part(s) are
           * the right part. Should there be more chars in the string, the right
           * parts are rejoined again with the specified char. 
           */
          left_part = parts.shift();
          right_part = parts.join(',');

          /* Add a left part to the new html if the left part isn't empty*/
          if (!empty(left_part))
          {
            new_html = new_html + '<span class="left">' + left_part + '</span>';
          }

          /* Add the specified char and the right part to the new html if 
           * the right part isn't empty*/
          if (!empty(right_part))
          {
            new_html = new_html + col.attr('char') + '<span class="right">' + right_part + '</span>';
          }

          /* If there is a new html, the width must be determined and a class is
           * added.
           * 
           * Note: outerWidth is used instead of width so padding, margin and
           * borders are taken into account.
           */
          if (!empty(new_html))
          {
            $(this).html(new_html); /* Set the new html. */
            $(this).addClass('char-align-' + i); /* Add a class to the table cell. */

            /* Get the left span to determine its outer width. */
            leftSpan = $(this).children('.left');

            if (!empty(leftSpan) && left_width < leftSpan.outerWidth())
            {
              left_width = leftSpan.outerWidth();
            }

            /* Get the right span to determine its outer width. */
            rightSpan = $(this).children('.right');

            if (!empty(rightSpan) && right_width < rightSpan.outerWidth())
            {
              right_width = rightSpan.outerWidth();
            }

          }

        });

        /* Only if any width is larger then 0, add a style. */
        if (left_width > 0 || right_width > 0)
        {
          style_text = '<style type="text/css">.fix-align-char td.char-align-' + (i) + ' span.left { float: left; text-align: right; width: ' + (left_width) + 'px; }\n.fix-align-char td.char-align-' + (i) + ' span.right { float: right; text-align: left; width: ' + right_width + 'px; }</style>';
          $('head').append(style_text);
        }

      }
    });
  });

}

$(document).ready(function(){
  alignNumbers();
});

Answer 2

Another way to format a number would be like this: 35<span style="visibility: hidden">.000</span>. That is, write it out with the full decimal expansion, but write the trailing decimals in invisible ink. That way you don't have to worry about the width of the decimal point.

Answer 3

Cheat; benefit of this solution: also works for proportional fonts. Have one extra column and split the integer part from the decimal separator and the decimals. Then use this css and combine two columns in the header row:

table {border-collapse:collapse;}
td {padding:0px;margin:0px;border:0px;}
td+td {text-align:right;}
td, td+td+td {text-align:left;}

<table>
    <tr><th>Name</th><th colspan=2>Height</th></tr>
    <tr><td>eiffeltower</td> <td>324</td> <td></td></tr>
    <tr><td>giraffe</td> <td>5</td> <td>,30</td></tr>
    <tr><td>deer</td> <td>1</td> <td></td></tr>
    <tr><td>mouse</td> <td>0</td> <td>,03</td></tr>
</table>

Answer 4

See this article by Krijn Hoetmer for your options and how to achieve this. The essence of this solution is to use CSS and JS to achieve this:

(function() {
  var currencies = /(\$|€|€)/;
  var leftWidth = 0, rightWidth = 0;
  for(var tableCounter = 0, tables = document.getElementsByTagName("table");
      tableCounter < tables.length; tableCounter++) {
    if(tables[tableCounter].className.indexOf("fix-align-char") != -1) {
      var fCols = [], leftPart, rightPart, parts;
      for(var i = 0, cols = tables[tableCounter].getElementsByTagName("col"); i < cols.length; i++) {
        if(cols[i].getAttribute("char")) {
          fCols[i] = cols[i].getAttribute("char");
        }
      }
      for(var i = 0, trs = tables[tableCounter].rows; i < trs.length; i++) {
        for(var j = 0, tds = trs[i].getElementsByTagName("td"); j < tds.length; j++) {
          if(fCols[j]) {
            if(tds[j].innerHTML.indexOf(fCols[j]) != -1) {
              parts = tds[j].innerHTML.split(fCols[j]);
              leftPart = parts.slice(0, parts.length -1).join(fCols[j]);
              leftPart = leftPart.replace(currencies, "<span class='currency'>$1</span>");
              rightPart = fCols[j] + parts.pop();
              tds[j].innerHTML = "<span class='left'>" + leftPart + "</span><span class='right'>" + rightPart + "</span>";
            } else {
              tds[j].innerHTML = tds[j].innerHTML.replace(currencies, "<span class='currency'>$1</span>");
              tds[j].innerHTML = "<span class='left'>" + tds[j].innerHTML + "</span>";
            }
            tds[j].className = "char-align";
            var txt = document.createTextNode(tds[j].firstChild.offsetWidth);
            if(leftWidth < tds[j].firstChild.offsetWidth) {
              leftWidth = tds[j].firstChild.offsetWidth;
            }
            if(tds[j].childNodes[1]) {
              txt = document.createTextNode(tds[j].childNodes[1].offsetWidth);
              if(rightWidth < tds[j].childNodes[1].offsetWidth) {
                rightWidth = tds[j].childNodes[1].offsetWidth;
              }
            }
          }
        }
      }
    }
  }
  // This is ugly and should be improved (amongst other parts of the code ;)
  var styleText = "\n" +
      "<style type='text/css'>\n" +
      "  .fix-align-char td.char-align { width: " + (leftWidth + rightWidth) + "px; }\n" +
      "  .fix-align-char span.left { float: left; text-align: right; width: " + leftWidth + "px; }\n" +
      "  .fix-align-char span.currency { text-align: left; float: left; }\n" +
      "  .fix-align-char span.right { float: right; text-align: left; width: " + rightWidth + "px; }\n" +
      "</style>\n";
  document.body.innerHTML += styleText;
})();

table {
  border-collapse: collapse;
  width: 600px;
}
th {
  padding: .5em;
  background: #eee;
  text-align: left;
}
td {
  padding: .5em;
}
#only-css td.char-align {
  width: 7em;
}
#only-css span.left {
  float: left;
  width: 4em;
  text-align: right;
}
#only-css span.currency {
  float: left;
  width: 2em;
  text-align: left;
}
#only-css span.right {
  float: right;
  width: 3em;
  text-align: left;
}

<table id="only-css">
  <thead>
    <tr>
      <th>Number</th>
      <th>Description</th>
      <th>Costs</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>1</td>
      <td>Lorem ipsum dolor sit amet</td>
      <td class="char-align">
        <span class="left">
          <span class="currency">$</span>3
        </span>
        <span class="right">,99</span>
      </td>
    </tr>
    <tr>
      <td>2</td>
      <td>Consectetuer adipiscing elit</td>
      <td class="char-align">
        <span class="left">
          <span class="currency">$</span>13
        </span>
        <span class="right">,95</span>
      </td>
    </tr>
    <tr>
      <td>3</td>
      <td>Pellentesque fringilla nisl ac mi</td>
      <td class="char-align">
        <span class="left">
          <span class="currency">$</span>4
        </span>
        <span class="right"></span>
      </td>
    </tr>
    <tr>
      <td>4</td>
      <td>Aenean egestas gravida magna</td>
      <td class="char-align">
        <span class="left">
          <span class="currency">$</span>123
        </span>
        <span class="right">,999</span>
      </td>
    </tr>
  </tbody>
</table>

Answer 5

can you just print the numbers so that they always have the same number of decimal places, and right align them?