Tag Archive for ‘plugin’ at ZachInglis.com

I have worked on many applications that require breadcrumbs. Every time, one of the developers has built a quick custom solution. Finally, I decided that we needed a complete solution that we could easily add to future projects, and thus Crummy was born.

Requirements

I set a few requirements that must be fulfilled in order for me to call the plugin a success. They were:

Ability to add breadcrumbs at Controller class level (like a before filter)
Ability to add breadcrumbs in the controller methods (such as actions)
Ability to add breadcrumbs from the views
Ability to add breadcrumbs with or without an url
No variable conflicts (such as instance variables)
Full and strong spec coverage
Good documentation

I managed to fulfill these requirements and add a few shiny methods to make life easy.

Examples of Usage


    class ApplicationController < ActionController::Baseee
      add_crumb 'Home', '/' # This will display on EVERY list of breadcrumbs
    end


    class BusinessController < ApplicationController
      # The load order DOES matter.
      add_crumb("Businesses") { |instance| instance.send :businesses_path } # Show on all actions
      add_crumb("Comments", :only => [:comments, :show]) { |instance| instance.send :business_comments_path } # Only add the comments link on the comments and show actions.
      before_filter :load_comment, :only => “show”

      def show
       add_crumb @business.display_name, @business
      end

      def load_comment
       @comment = Comment.find(params[:id])
      end
    end

Golden Feature

One of the most useful argument usage is add_crumb :comment. What this does is turns the symbol into an instance variable (@comment.) Then it roughly translates into:

  # add_crumb :comment
  before_filter :add_comment_breadcrumb
  def add_comment_breadcrumb
    add_crumb @comment.to_s, @comment
  end

Installation

script/plugin install git://github.com/zachinglis/crummy.git

In one of my projects, I mix together two ActiveRecord objects for listing. There is two ways that I could have done this. A seperate model that enfolds my models or merging them with a concat. I did it this way as it only happened once so no need to create yet-another file.

After reading this post, I got a better idea of what to do. That code was OK but I refactored it into better, cleaner and more understandable code.

def list foo = Foo.find :all bar = Bar.find :all foo_bar = foo.concat bar # merge the two arrays foo_bar = foo_bar.sort_by { |foos_and_bars| foos_and_bars.created_at } # reorganize by created_at date end

I then created a private method for pagination. I’ve stuck this in my local controller but the application-wide controller may be a better idea if you use it in different controllers.

Anyway, here be the code:
def paginate_array(array, per_page_param=25, page_number_param=0) per_page_number = per_page_param.to_i == 0 ? 25 : per_page_param.to_i page_number = page_number_param.nil? 0 : page_number_param.to_i page_number = per_page_number * page_number


    array_count = 0

    array.collect { array_count += 1 } # Array does not have the count method so this works nicely.

WillPaginate::Collection.new(page_number, per_page_number, array_count).concat_array end

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