Dmitry Polushkin

[Ruby] Refactoring of the location selector (5 levels)

2009-05-14T13:09:01-07:00

It's a Location selector, from Continent till Suburb.
There are a different rules:

* Next selection must appear if only previous level been selected
* If no children on current level, then all next levels show as a text fields
* If level > OPTION_CAPABLE, then must appear option "Other"
* If Other selected, then self and all next levels must show as a text fields

/me start to write tests for this biiig view partial.

Thanks.

## Model [Location]

acts_as_nested_set
OPTION_CAPABLE = 2
LEVELS = [:continent, :country, :region, :town, :suburb]

## View [html_rails]

<% ancestors = location.self_and_ancestors if location %>

<%= hidden_field_tag 'products[location_id]', location ? location.id : nil %>

<% is_text_field = false %>
<% Location::LEVELS.each_with_index do |level, level_number| %>
  <% previous_ancestor = (ancestors ? ancestors[level_number - 1] : nil) %>
  <% ancestor = (ancestors ? ancestors[level_number] : nil) %>
  <div id="location_<%= level %>_container">
    <% children = (previous_ancestor ? previous_ancestor.children : []) %>
    <% options = (0 == level_number ? Location.roots : children).map { |l| [l.name, l.id] } %>

    <% if options.size > 0 %>
      <%= label_tag :"select_location_#{level}" %>:

      <% options = [[Location.human_attribute_value(:name, :value => :select), '']] + options %>
      <% options += [[Location.human_attribute_value(:name, :value => :other), 0]] if level_number > Location::OPTION_CAPABLE %>

      <%= select_tag :"location_#{level}", options_for_select(options, (ancestor ? ancestor.id : nil) || params[:other].to_i) %> - <%=  (ancestor ? ancestor.id : nil) || params[:other].to_i %><br/>
    <% end %>
    
    <% if (Location::LEVELS.last != level && !ancestor.nil? && ancestor.children.size == 0) || (ancestor.nil? && params[:other]) || is_text_field %>
      <% is_text_field = true %>

      <% unless !ancestor.nil? && ancestor.children.size == 0 %>
        <%= label_tag :"type_location_#{level}" %>:
        <%= text_field_tag :a, :a %>
      <% end %>
    <% end %>
  </div>
<% end %>

[Ruby] On Too many for loops

2009-02-25T05:43:52-08:00

Why do you think is it bad?

[JavaScript] Check next option in select tag

2009-01-25T15:04:15-08:00

Could be written in plain javascript or prototype (or jQuery).

var next = false;
for (var i = 0; i < el.options.length; i++) {
  if (next) {
    next = false;
    el.options[i].selected = true;
    break;
  }
  if (el.options[i].selected) {
    el.options[i].selected = false;
    next = true;
  }
}
if (next) {
  el.options[0].selected = true;
}

[Ruby] On While loop to get unique value

2009-01-22T10:06:04-08:00

What about magic number '8'?

[Ruby] On Slurping popen

2009-01-22T10:01:13-08:00

%x[ls]

[Ruby] On Conversion from the 2d array to hash.

2008-10-22T18:21:13-07:00

Something like I have written for the refactoring: http://github.com/rails/rails/tree/master/activesupport/lib/active_support/ordered_hash.rb#L37

I think I will use native activesupport OrderedHash class for converting to_hash...

@danieharan: yes, in some cases I cant, but this array I'm getting from the Asset.count(:group => 'column_type'), so it's fixed width with two values: column_type + count value. By the benchmark it's not very optimized, and also it's not so simple, that it might be.

@Adam: I don't need the ordering, but anyway it's good that activesupport have that class. But why native Array class doesn't have to_h or to_hash? Strange for me.

[Ruby] On Conversion from the 2d array to hash.

2008-10-22T14:24:03-07:00

@danielharan: is it faster than Hash[*a.flatten] ?

[Ruby] On Extract text between {} brackets

2008-10-22T14:20:29-07:00

res = path_without_calculation.scan(/\{(.*?)\}/).flatten

[Ruby] On Conversion from the 2d array to hash.

2008-10-22T14:17:03-07:00

Thanks! Why no "to_h" method in ruby Hash native class? Inverting to_a changes? {:a => 1, :b => 2}.to_a.to_h

[Ruby] Conversion from the 2d array to hash.

2008-10-22T09:11:29-07:00

Conversion from the 2d array to hash.

class Array
  def to_h
    hash = {}
    self.each do |entry|
      hash[entry[0]] = entry[1]
      # Yes, we could write: key, value = entry, 
      # but it isn't optimized, to_h must be optimized, 
      # because it's a very little method
    end
    hash
  end
end

p [['a', '1'], ['b', '2']].to_h
# {"a"=>"1", "b"=>"2"}

[Ruby] On Open hours grouping

2008-10-16T06:20:39-07:00

I have some idea how to improve it, but don't have free time to implement. Will write my refactoring in about a one-two weeks.

[Ruby] On Open hours grouping

2008-10-16T06:18:47-07:00

@tmpr: You have an error in your output. Must be:
"opening_hours_mon - opening_hours_tue, opening_hours_thu: 9:00 - 20:00
Also must be sorted in a better way, not: sun, sat, fri, mon, tue... but mon, tue, wed... etc.
Also is very strange:
"opening_hours_sat, opening_hours_sun: closed", I think it must be "opening_hours_sat - opening_hours_sun: closed", by the previous example (opening_hours_tue - opening_hours_mon, opening_hours_thu: 9:00 - 20:00) logic?

I like code of the previous one, by Adam.

[Ruby] Open hours grouping

2008-10-08T09:13:00-07:00

Actually I really don't know how to refactor it into a better way.

Thanks for your help.

WEEKDAYS = %w(mon tue wed thu fri sat sun)

dates = [
  {:day => WEEKDAYS[0], :time => '9:00 - 20:00'},
  {:day => WEEKDAYS[1], :time => '9:00 - 20:00'},
  {:day => WEEKDAYS[2], :time => '9:00 - 20:00'},
  {:day => WEEKDAYS[3], :time => '8:00 - 19:00'},
  {:day => WEEKDAYS[4], :time => '9:00 - 20:00'},
  {:day => WEEKDAYS[5], :time => '8:00 - 19:00'},
  {:day => WEEKDAYS[6], :time => 'closed'}
]



def build_opening_hours dates
  ret = []

  dates.each do |day|
    d = ret.detect {|v| day[:time] == v[:time] }
    if d.nil?
      ret.push({:days => [day[:day]], :time => day[:time]})
    else
      d[:days] << day[:day]
    end
  end

  data = []

  ret.each do |v|
    previous = nil
    v[:days].each do |day|
      index = WEEKDAYS.index(day)
      day_text = "opening_hours_#{day}"
      if previous.nil?
        data.push([day_text, v[:time]])
      else
        if ((index - 1) == previous)
          data.last[0] = data.last[0].gsub(/ - .*$/, '')
          data.last[0] += ' - ' + day_text
        else
          data.last[0] += ', ' + day_text
        end
      end
      previous = index
    end
  end

  ret = []

  data.each do |d|
    ret.push(d.join(': '))
  end

  ret
end

p build_opening_hours(dates)

# [
# "opening_hours_mon - opening_hours_wed, opening_hours_fri: 9:00 - 20:00",
# "opening_hours_thu, opening_hours_sat: 8:00 - 19:00",
# "opening_hours_sun: closed"
# ]