Generate an HTML table from an array of hashes in Ruby

# modified from Harish's answer, to take care of sparse hashes:require 'builder'def hasharray_to_html( hashArray )  # collect all hash keys, even if they don't appear in each hash:  headers = hashArray.inject([]){|a,x| a |= x.keys ; a}  # use array union to find all unique headers/keys                                html = Builder::XmlMarkup.new(:indent => 2)  html.table {    html.tr { headers.each{|h| html.th(h)} }    hashArray.each do |row|      html.tr { row.values.each { |value| html.td(value) }}    end  }  return htmlend

Use the XMLBuilder for this:

data = [{"col1"=>"v1", "col2"=>"v2"}, {"col1"=>"v3", "col2"=>"v4"}]xm = Builder::XmlMarkup.new(:indent => 2)xm.table {  xm.tr { data[0].keys.each { |key| xm.th(key)}}  data.each { |row| xm.tr { row.values.each { |value| xm.td(value)}}}}puts "#{xm}"

Output

<table>  <tr>    <th>col1</th>    <th>col2</th>  </tr>  <tr>    <td>v1</td>    <td>v2</td>  </tr>  <tr>    <td>v3</td>    <td>v4</td>  </tr></table>

You can use builder:

require 'builder'a = [{"col1"=>"v1", "col2"=>"v2"}, {"col1"=>"v3", "col2"=>"v4"}]builder = Builder::XmlMarkup.newcolumns = a.first.keysbuilder.table do |t|  t.tr do |tr|    columns.each do |col|      tr.th(col)    end  end  a.each do |row|    t.tr do |tr|      columns.each do |col|        tr.td(row[col])      end    end  endendp builder.target#=> "<table><tr><th>col1</th><th>col2</th></tr><tr><td>v1</td><td>v2</td></tr><tr><td>v3</td><td>v4</td></tr></table><target/>"