Ruby on Rails URL Format

I have a Ruby on Rails application where you can create 'posts'. I started of by using the scaffold generator to give generate the title which is a string and the body which is the content.

Each 'post' has a url of the id, for example /1, /2, /3, etc.

Is there a way to change that to a string of random characters, for example /49sl, /l9sl, etc?

Update

Here is what I have for the posts_controller.rb

class PostsController < ApplicationController
  # GET /posts
  # GET /posts.json
  def index
    @posts = Post.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @posts }
    end

  end

  # GET /posts/1
  # GET /posts/1.json
  def show
    @post = Post.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @post }

    end
  end

  # GET /posts/new
  # GET /posts/new.json
  def new
    @post = Post.new

    respond_to do |format|
      format.html # new.html.erb

      format.json { render json: @post }
    end
  end

  # GET /posts/1/edit
  def edit
    @post = Post.find(params[:id])
  end

  # POST /posts

  # POST /posts.json
  def create
   @post = Post.new(params[:post])

    respond_to do |format|
      if @post.save
        format.html { redirect_to @post, notice: 'Post was successfully created.' }
        format.json { render json: @post, status: :created, location: @post }
      else
        format.html { render action: "new" }

        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /posts/1
  # PUT /posts/1.json
  def update
    @post = Post.find(params[:id])


    respond_to do |format|
      if @post.update_attributes(params[:post])
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end


  # DELETE /posts/1
  # DELETE /posts/1.json
  def destroy
    @post = Post.find(params[:id])
    @post.destroy

    respond_to do |format|
      format.html { redirect_to posts_url }
      format.json { head :no_content }

    end
  end
end

Answer

You can give your posts random URLs by following these 3 steps:

1- In your model (Post.rb), generate a random string for each post before it is saved. For example,

class Post < ActiveRecord::Base

  before_create :generate_url_id
  def generate_url_id
    self.url_id = SecureRandom.urlsafe_base64
  end
end

2- In your model (Post.rb), supply a to_param method to override Rails default URL generation. For example:

class Post < ActiveRecord::Base

  def to_param
    self.url_id
  end
end

3- In your controller (PostsController.rb), use a dynamic finder to find your post by its random string. For instance,

class PostsController < ApplicationController
  def show

    @post = Post.find_by_url_id(params[:id])
    ...
  end
end

I went ahead and put together a complete example and posted it to Github.