rails code

ActiveRecord::Errors#to_xml

Here’s a method that will allow you to call to_xml on an ActiveRecord::Errors object. We’re using this to pass errors between web apps via a web service api.

class ActiveRecord::Errors
  def to_xml(options = {})
    options[:indent] ||= 2
    options.reverse_merge!({ :builder =>
      Builder::XmlMarkup.new(:indent =>
        options[:indent]), :root => "errors" })
    options[:builder].instruct! unless options.delete(:skip_instruct)

    options[:builder].__send__(options[:root].to_s.dasherize) do |xml|
      @errors.each do |key, value|
        xml.__send__(key.to_s.dasherize) do |xm|
          for message in value
            xm.message(message)
          end
        end
      end
    end

  end
end

to ruby rails activerecord Errors web-service by canadaduane on Apr 25, 2006 1 Comments

Validate URIs by Pinging the Server

require 'open-uri'

class ActiveRecord::Base
  def self.validates_uri_existence_of(*attr_names)
    configuration = { :message => "is not a valid web address" }
    configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
    validates_each attr_names do |m, a, v|
      begin
        # Try to open the URI
        open v
      rescue
        # Report the error if it throws an exception
        m.errors.add(a, configuration[:message])
      end
    end
  end
end

Details on my blog.

to ruby rails url uri validation by canadaduane on Apr 13, 2006

Use background color to show error fields instead of wrapping them in a div

Using the default rails field_error_proc may lead to some layout headaches--your form looks perfect until, uh-oh, someone entered an invalid email address and Rails adds a fieldWithError-styled div that wraps around the problem field.

While this works in many cases, some pixel-perfect layouts may not be able to tolerate the 2-pixel padding around the text_field caused by the red border. An alternative is to change the background color of the offending field.

Include the following code in environment.rb (or use a "require" like I do):

ActionView::Base.field_error_proc = Proc.new do |html_tag, instance|
  error_style = "background-color: #ffff80"
  if html_tag =~ /<(input|textarea|select)[^>]+style=/
    style_attribute = html_tag =~ /style=['"]/
    html_tag.insert(style_attribute + 7, "#{error_style}; ")
  elsif html_tag =~ /<(input|textarea|select)/
    first_whitespace = html_tag =~ /\s/
    html_tag[first_whitespace] = " style='#{error_style}' "
  end
  html_tag
end

See my blog.inquirylabs.com for more Rails stuff.

to ruby rails stylesheets Errors field field_error_proc by canadaduane on Apr 13, 2006 2 Comments

content_tag that accepts a block = block_tag

Sometimes I want to do something like this:

<% content_tag("div", :class => "section_with_error" do %>
  HTML GOES HERE
<% end %>

instead of this:

<%= content_tag("div", "HTML GOES HERE", :class => "section_with_error") %>

Put the following code in ApplicationHelper, and you can do just that (replacing "content_tag" in the example above with "block_tag", of course):

  def block_tag(tag, options = {}, &block)
    concat(content_tag(tag, capture(&block), options), block.binding)
  end

to ruby rails block tag by canadaduane on Apr 12, 2006

Parse Technorati-style Tags from HTML

An enhancement to the String class that parses out Technorati-style tags. Uses Typo's strip_html method to remove img tags and other markup.

class String
  # Strips any html markup from a string
  TYPO_TAG_KEY = TYPO_ATTRIBUTE_KEY = /[\w:_-]+/
  TYPO_ATTRIBUTE_VALUE = /(?:[A-Za-z0-9]+|(?:'[^']*?'|"[^"]*?"))/
  TYPO_ATTRIBUTE = /(?:#{TYPO_ATTRIBUTE_KEY}(?:\s*=\s*#{TYPO_ATTRIBUTE_VALUE})?)/
  TYPO_ATTRIBUTES = /(?:#{TYPO_ATTRIBUTE}(?:\s+#{TYPO_ATTRIBUTE})*)/
  TAG = %r{<[!/?\[]?(?:#{TYPO_TAG_KEY}|--)(?:\s+#{TYPO_ATTRIBUTES})?\s*(?:[!/?\]]+|--)?>}
  def strip_html
    self.gsub(TAG, '').gsub(/\s+/, ' ').strip
  end

  def tags
    scan(/<a\s+[^>]*\s*rel=\s*(.?)tag\1[^>]*>(.+?)<\/a>/i).
    map { |match| match.last.strip_html rescue nil }.
    compact.select { |s| !s.strip.empty? }
  end
end

# Example usage

s = %{<a href="http://www.docstrangelove.com/tag/civil-war" rel="tag">civil war</a> <a href="http://www.technorati.com/tag/civil+war" rel="tag"><img src="http://www.docstrangelove.com/wp-content/plugins/UltimateTagWarrior/technoratiicon.jpg" alt="Technorati tag page for civil war"/></a> <a href="http://www.docstrangelovecom/tag/iraq" rel="tag">iraq</a> <a href="http://www.technorati.com/tag/iraq" rel="tag"><img src="http://www.docstrangelove.com/wp-content/plugins/UltimateTagWarrior/technoratiicon.jpg" alt="Technorati tag page for iraq"/></a>}

s.tags
# => ["civil war", "iraq"]

to ruby rails tags string by canadaduane on Mar 24, 2006

Firing a controller's action from the console

It seems like a simple task, but here's how you can simulate the calling of a controller's action:

ruby script/console

irb> require 'action_controller/test_process'
irb> require 'application'
irb> require 'site_controller'
irb> request = ActionController::TestRequest.new
irb> response = ActionController::TestResponse.new
irb> request.env['REQUEST_METHOD'] = 'GET'
irb> request.action = "late_employee"
irb> InfoController.process(request,response)

Basically, it's like getting inside of a TestUnit method, but you have to do the dirty work yourself.

to ruby rails controller action by canadaduane on Aug 25, 2005 4 Comments

Make an html link update several dom elements at the same time.

    <a href="#" onClick="<%= remote_function(:update => 'fashion1', :url => { :action => :get_fashion_for_color, :color_name => color_name, :number => 1 })%>;
                         <%= remote_function(:update => 'fashion2', :url => { :action => :get_fashion_for_color, :color_name => color_name, :number => 2 })%>;
                         <%= remote_function(:update => 'fashion3', :url => { :action => :get_fashion_for_color, :color_name => color_name, :number => 3 })%>;
                         return false;">

to ruby rails ajax link remote_function by canadaduane on Jul 29, 2005 1 Comments

Autoinclude CSS Files by Controller/Action Name

def stylesheet_auto_link_tags
  stylesheets_path = "#{RAILS_ROOT}/public/stylesheets/"
 
  candidates = [ "#{controller.controller_name}", 
                 "#{controller.controller_name}_#{controller.action_name}" ]
 
  candidates.inject("") do |buf, css| 
    buf << stylesheet_link_tag(css) if FileTest.exist?("#{stylesheets_path}/#{css}.css")
    buf
  end
end

Compliments of Dema

Note: Anyone interested in this might also be interested in the bundled_resource plugin (google for it).

to ruby rails css stylesheets by canadaduane on Jul 26, 2005 2 Comments

Render a partial to an instance variable

Normally, if you call "render_partial" within a controller, nothing but the partial will be rendered.

Occasionally, it is useful to render a partial to an instance variable as a string so that the view can still be rendered as normal, and the string can be passed in to the view.

  add_variables_to_assigns
  @content_for_navbar = @template.render_partial 'layouts/public_navbar'

to ruby rails template partial controller assigns by canadaduane on Jun 19, 2005 2 Comments

Paginate an already-fetched result set (i.e. collection or array)

Sometimes it's nearly impossible to paginate a result set using the built-in :limit and :offset parameters of find(:all). Instead, you can fetch a complicated query and paginate the results afterward.

Add the following to application.rb:

  def paginate_collection(collection, options = {})
    default_options = {:per_page => 10, :page => 1}
    options = default_options.merge options
    
    pages = Paginator.new self, collection.size, options[:per_page], options[:page]
    first = pages.current.offset
    last = [first + options[:per_page], collection.size].min
    slice = collection[first...last]
    return [pages, slice]
  end

Call it from within your action like this:

@pages, @users = paginate_collection User.find_custom_query, :page => @params[:page]

to ruby rails pagination by canadaduane on Jun 16, 2005 8 Comments

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