I am using slugs in my project to give my params an other name but I have two params called: "how-does-it-work".
(.../investor/how-does-it-work)
(.../customer/how-does-it-work)
I would like to use the slugs as how they are currently set.
Is there a way to do that?
Create two distinct routes/controllers, and simply query the corresponding ActiveRecord model in the show action. Assuming there is a slug field on your models:
Rails.application.routes.draw do
resources :customers
resources :investors
end
class CustomersController < ApplicationController
def show
#customer = Customer.find_by(slug: params[:id])
end
end
class InvestorsController < ApplicationController
def show
#investor= Investor.find_by(slug: params[:id])
end
end
This is probably the most conventional way to solve this problem in Rails. If you are using the friendly_id gem, the same approach more or less applies, except for maybe the query itself.
Hope this helps.
So, is /investor/ and /customer/ both parts of the slug?
If that's the case, you can split the string, and do a search based on the "how-does-it-work" in the grouping of "investor" or "customer".
If investor and customer are both parts of the routes, you shouldn't have a difficult time there, because they're pointing to two different controller methods. You should be able to write a search based on each of those methods that correspond to the data. If the data is the same, all your doing is pointing the controller to the correct model data with the correct params.
If you're using friendlyId, it usually has built in candidate matching. Also, if you're meaning to match multiple pages to the same slug (which I've done in the past), you can display a results page if you'd like too, by rendering based on the quantity of results.
Related
I have a Model called Category and another called Articles. Categories are "sections" that have many Articles, for instance News and Events. Both Categories use the kind of Articles, except they're shown under a different section of my website.
Right now I'm creating the News controller (NewsController), and I'd like to visit /news/new to add News. Likewise, the same would apply to EventsController and /events/new.
What do I have to use on my routes to do this?
My first attempt was to use:
resources :categories do
resources :articles, path: '/news'
end
But this forces me to use /categories/1/news/new, which is kinda ugly.
If News will always be category_id 1 and Events will always be 2, how would I specify this on my routes, so I can easily access them with the URLs I mentioned?
Explained Differently
I have an Articles model. I'd like to have a controller called NewsController to handle Articles, so that /news/new (and the rest of the paths) would work with Article. I'd also like to have a controller called EventsController that would also handle Articles, so that /events would also work with Article. The difference between them is that they have different category_id.
Is this possible to do via routes?
Update
Made some progress.
resources :categories do
resources :articles
end
get 'news/new' => 'articles#new', defaults: {category_id: 1}
get 'events/new' => 'articles#new', defaults: {category_id: 2}
This fixes what I wanted to do with /news/new and /events/new, but I'd be missing the rest of the routes (edit, show, update, etc). Also, this makes me use the Articles controller, which currently does not exist and would also make the News controller obsolete/useless.
My logic may be wrong, it's kinda evident with what I just made, but perhaps with this update I can better illustrate what I'm trying to do.
Update 2
I'm currently testing the following:
resources :articles, path: '/news', controller: 'news'
resources :articles, path: '/events', controller: 'events'
So far it makes sense, it makes the routes I wanted, it uses both controllers with their own configurations, and it hasn't spat any errors when I visit both /news and /events (yet).
It's also possible to do:
resources :articles, path: '/news', defaults: {category_id: 1}
resources :articles, path: '/events', defaults: {category_id: 2}
But this would depend on an Article controller, which could handle both types of Categories. Either solution works (theoretically), though I'd incline more on the first since the individual controllers would allow more specific configuration to both cases. The second, though, is more adequate when there're not that many difference between the Articles being created. The defaults property isn't explicitly necessary either, I just put it there for convenience.
Your question is asking something that I question as not making sense and maybe your design is flawed.
Why would you have news resources related to category resources if they are not related?
Is categories just a name space?
If news records really are always going to be related to the same first category as your question implies then you can not use ID's as you have no control over what the id will be for the first category and the first category could have an ID of anything in which case you could just use the top level news resources and do a find first category in your model in a before create then you don't have to worry about an ugly url.
If news records really are related to categories then the you must supply the relevant category id and nest your routes but you could pretty up the url using the following from
https://gist.github.com/jcasimir/1209730
Which states the following
Friendly URLs
By default, Rails applications build URLs based on the primary key --
the id column from the database. Imagine we have a Person model and
associated controller. We have a person record for Bob Martin that has
id number 6. The URL for his show page would be:
/people/6
But, for aesthetic or SEO purposes, we want Bob's name in the URL. The
last segment, the 6 here, is called the "slug". Let's look at a few
ways to implement better slugs. Simple Approach
The simplest approach is to override the to_param method in the Person
model. Whenever we call a route helper like this:
person_path(#person)
Rails will call to_param to convert the object to a slug for the URL.
If your model does not define this method then it will use the
implementation in ActiveRecord::Base which just returns the id.
For this method to succeed, it's critical that all links use the
ActiveRecord object rather than calling id. Don't ever do this:
person_path(#person.id) # Bad!
Instead, always pass the object:
person_path(#person)
Slug Generation
Instead, in the model, we can override to_param to include a
parameterized version of the person's name:
class Person < ActiveRecord::Base def to_param
[id, name.parameterize].join("-") end end
For our user Bob Martin with id number 6, this will generate a slug
6-bob_martin. The full URL would be:
/people/6-bob-martin
The parameterize method from ActiveSupport will deal with converting
any characters that aren't valid for a URL. Object Lookup
What do we need to change about our finders? Nothing! When we call
Person.find(x), the parameter x is converted to an integer to perform
the SQL lookup. Check out how to_i deals with strings which have a mix
of letters and numbers:
"1".to_i
=> 1
"1-with-words".to_i
=> 1
"1-2345".to_i
=> 1
"6-bob-martin".to_i
=> 6
The to_i method will stop interpreting the string as soon as it hits a
non-digit. Since our implementation of to_param always has the id at
the front followed by a hyphen, it will always do lookups based on
just the id and discard the rest of the slug. Benefits / Limitations
We've added content to the slug which will improve SEO and make our
URLs more readable.
One limitation is that the users cannot manipulate the URL in any
meaningful way. Knowing the url 6-bob-martin doesn't allow you to
guess the url 7-russ-olsen, you still need to know the ID.
And the numeric ID is still in the URL. If this is something you want
to obfuscate, then the simple scheme doesn't help. Using a Non-ID
Field
Sometimes you want to get away from the ID all together and use
another attribute in the database for lookup. Imagine we have a Tag
object that has a name column. The name would be something like ruby
or rails. Link Generation
Creating links can again override to_param:
class Tag < ActiveRecord::Base validates_uniqueness_of :name
def to_param
name end end
Now when we call tag_path(#tag) we'd get a URL like /tags/ruby. Object
Lookup
The lookup is harder, though. When a request comes in to /tags/ruby
the ruby will be stored in params[:id]. A typical controller will call
Tag.find(params[:id]), essentially Tag.find("ruby"), and it will fail.
Option 1: Query Name from Controller
Instead, we can modify the controller to
Tag.find_by_name(params[:id]). It will work, but it's bad
object-oriented design. We're breaking the encapsulation of the Tag
class.
The DRY Principle says that a piece of knowledge should have a single
representation in a system. In this implementation of tags, the idea
of "A tag can be found by its name" has now been represented in the
to_param of the model and the controller lookup. That's a maintenance
headache. Option 2: Custom Finder
In our model we could define a custom finder:
class Tag < ActiveRecord::Base validates_uniqueness_of :name
def to_param
name end
def self.find_by_param(input)
find_by_name(input) end end
Then in the controller call Tag.find_by_param(params[:id]). This layer
of abstraction means that only the model knows exactly how a Tag is
converted to and from a parameter. The encapsulation is restored.
But we have to remember to use Tag.find_by_param instead of Tag.find
everywhere. Especially if you're retrofitting the friendly ID onto an
existing system, this can be a significant effort. Option 3:
Overriding Find
Instead of implementing the custom finder, we could override the find
method:
class Tag < ActiveRecord::Base #... def self.find(input)
find_by_name(input) end end
It will work when you pass in a name slug, but will break when a
numeric ID is passed in. How could we handle both?
The first temptation is to do some type switching:
class Tag < ActiveRecord::Base #... def self.find(input)
if input.is_a?(Integer)
super
else
find_by_name(input)
end end end
That'll work, but checking type is very against the Ruby ethos.
Writing is_a? should always make you ask "Is there a better way?"
Yes, based on these facts:
Databases give the id of 1 to the first record
Ruby converts strings starting with a letter to 0
class Tag < ActiveRecord::Base #... def self.find(input)
if input.to_i != 0
super
else
find_by_name(input)
end end end
Or, condensed down with a ternary:
class Tag < ActiveRecord::Base #... def self.find(input)
input.to_i == 0 ? find_by_name(input) : super end end
Our goal is achieved, but we've introduced a possible bug: if a name
starts with a digit it will look like an ID. If it's acceptable to our
business domain, we can add a validation that names cannot start with
a digit:
class Tag < ActiveRecord::Base #... validates_format_of :name,
:without => /^\d/ def self.find(input)
input.to_i == 0 ? find_by_name(input) : super end end
Now everything should work great! Using the FriendlyID Gem
Does implementing two additional methods seem like a pain? Or, more
seriously, are you going to implement this kind of functionality in
multiple models of your application? Then it might be worth checking
out the FriendlyID gem: https://github.com/norman/friendly_id Setup
The gem is just about to hit a 4.0 version. As of this writing, you
want to use the beta. In your Gemfile:
gem "friendly_id", "~> 4.0.0.beta8"
Then run bundle from the command line. Simple Usage
The minimum configuration in your model is:
class Tag < ActiveRecord::Base extend FriendlyId friendly_id :name
end
This will allow you to use the name column or the id for lookups using
find, just like we did before. Dedicated Slug
But the library does a great job of maintaining a dedicated slug
column for you. If we were dealing with articles, for instance, we
don't want to generate the slug over and over. More importantly, we'll
want to store the slug in the database to be queried directly.
The library defaults to a String column named slug. If you have that
column, you can use the :slugged option to automatically generate and
store the slug:
class Tag < ActiveRecord::Base extend FriendlyId friendly_id
:name, :use => :slugged end
Usage
You can see it in action here:
t = Tag.create(:name => "Ruby on Rails")
=> #
Tag.find 16
=> #
Tag.find "ruby-on-rails"
=> #
t.to_param
=> "ruby-on-rails"
We can use .find with an ID or the slug transparently. When the object
is converted to a parameter for links, we'll get the slug with no ID
number. We get good encapsulation, easy usage, improved SEO and easy
to read URLs.
If you are sure there will be only 2 categories, why not simply add a boolean to the articles?
Like: article.event = true if events category, false if news
Then you can add a scopes to Article class for both categories
class Article
scope :events, -> { where(event: true) }
scope :news, -> { where(event: false) }
end
Create controllers, for example:
class EventsController < ApplicationController
def index
#articles = Article.events
end
def create
#article.new(params)
#article.event = true
#article.save
end
...
end
and routes: resources :events
You should try to use dynamic segments: http://guides.rubyonrails.org/routing.html#route-globbing-and-wildcard-segments
Add some slug attribute to Category, it should be unique and add index to it.
# routes
resources :articles, except: [:index, :new]
get '*category_slug/new', to: 'articles#new'
get '*category_slug', to: 'articles#index'
# controller
class ArticlesController < ApplicationController
def index
#category = Category.find_by slug: params[:category_slug]
#articles = #category.articles
end
def new
#category = Category.find_by slug: params[:category_slug]
#article = #category.articles.build
end
...
end
Remember to put a category in a hidden field in the form_for #article
On Rails 4.2, I would like to use Friendly Id for routing to a specific model, but dont wan't to create a slug column on the model table. I would instead prefer to use an accessor method on the model and dynamically generate the slug. Is this possible? I couldn't find this in the documentation.
You can not do this directly using friendly id because of the way it uses the slug to query the database (relevant source).
However it is not difficult to accomplish what you want. What you will need are two methods:
Model#slug method which will give you slug for a specific model
Model.find_by_slug method which will generate the relevant query for a specific slug.
Now in your controllers you can use Model.find_by_slug to get the relevant model from the path params. However implementing this method might be tricky especially if your Model#slug uses a non-reversible slugging implementation like Slugify because it simply get rids of unrecognized characters in text and normalizes multiple things to same character (eg. _ and - to -)
You can use URI::Escape.encode and URI::Escape.decode but you will end up with somewhat ugly slugs.
As discussed here I went with the following approach for custom routing based on dynamic slug.
I want custom route like this: /foos/the-title-parameterized-1 (where "1" is the id of the Foo object).
Foo model:
#...
attr_accessor :slug
#dynamically generate a slug, the Rails `parameterize`
#handles transforming of ugly url characters such as
#unicode or spaces:
def slug
"#{self.title.parameterize[0..200]}-#{self.id}"
end
def to_param
slug
end
#...
routes.rb:
get 'foos/:slug' => 'foos#show', :as => 'foo'
foos_controller.rb:
def show
#foo = Foo.find params[:slug].split("-").last.to_i
end
In my show view, I am able to use the default url helper method foo_path.
I'm in the process of learning Ruby on Rails, and now I have created the mobile version of my application.
I created the relation between models ans controller is one-one. Now I want to make changes to manage three models from one controller. I have read and watch videos a lot about how to do this but, it doesn't work when I try to do it in my application.
Models:
class Subject < ActiveRecord::Base
has_many :pages
class Page < ActiveRecord::Base
belongs_to :subject
has_many :sections
class Section < ActiveRecord::Base
belongs_to :page
Controller:
class SubjectsController < ApplicationController
has_mobile_fu
layout "admin"
before_action :confirm_logged_in
def index
#subjects = Subject.newest_first
#pages = #subjects.pages.sorted
end
This is the error:
NoMethodError (undefined method pages' for # <ActiveRecord::Relation::ActiveRecord_Relation_Subject:0x007fbbf3c9b218>):
app/controllers/subjects_controller.rb:10:inindex'
The application works well if I keep each model managed by its controller. The problem started now that I want to control multiple models from one controller.
Can definitely use multiple models in a single controller. The issue here is you're calling a method that doesnt exist for the active record relation.
An active record relation is typically a collection of returned objects from a query using active record. So the newest_first is returning multiple, not just one. If you want to get all pages for the subjects and sort them, you can do this:
#subjects = Subject.newest_first
#pages = #subjects.map(&:pages).flatten.sort { |a, b| a.title <=> b.title }
Can switch the attribute on which you wish to sort by. The map function goes through each one, and returns the object of which i passed in the symbol. It's a shortcut for:
#subjects.map { |subject| subject.pages }
The flatten then takes that array of active record relations and flattens it into a single array. I then just use the array sort.
Edit Here's a way you can do it using the database:
#subjects = Subject.newest_first
#pages = Page.where.not(:subject_id => nil).order(:title)
MVC
Something else you'll benefit from is to look at the MVC Programming Pattern:
Rails is famous for its strict coherence to the Model-View-Controller pattern, as it works like this:
You send a request to your app
Rails "routes" your request to a specific controller / action
The controller will then collate data from your Models
The controller will then render a view to display this data
The relationship between models and controllers is exclusive; meaning you don't have to call certain models from a controller, etc.
So the basic answer is no, you don't need to call a single model from a controller. However, you do need to ensure you have the correct model associations set up, as per the explanation below:
Associations
The caveat here, is that since Ruby is object-orientated (and Rails, by virtue of being built on Ruby, also being so), it's generally considered best practice to build your application around objects
"Objects" are basically elaborate variables (constructed from your Model classes), but the pattern behind making OOP work properly is super important - everything from Rails' routes to your controller actions are designed to be object-ORIENTATED
Each time you initiate an instance of a Model, Rails is actually building an object for you to use. This object allows you to call / use a series of attributes / methods for the object, allowing you to create the experience you require with Rails
--
The bottom line -
I would highly recommend examining the ActiveRecord Associations in your models (which will determine whether you need to call a single model or not):
#app/controllers/subjects_controller.rb
Class SubjectsController < ApplicationController
def index
#subjects = Subject.newest_first #-> good use of OOP
#posts = # this is where your error occurs (`.posts` is only an attribute of each `Subject` object instance, which is fixed using the accepted answer)
end
end
Hopefully this gives you some more ideas about how to construct Rails applications
I have the following show-view, where i display basic information about Product and display other User's Products.
<h1>Book <%= #product.name %></h1>
<% #products.each do |product| %>
<ul>
<%= product.name %>
<%= link_to "Make offer", {controller: "offers", :action => 'create', id: product.id } %>
</ul>
Controller
def show
#product = current_user.products.find(params[:id])
#products = Product.all
end
My goal is to make Offer between two Products.
I created Offer model and methods for making Offers:
class Offer < ActiveRecord::Base
belongs_to :product
belongs_to :exchanger, class_name: "Product", foreign_key: "exchanger_id"
validates :product_id, :exchanger_id, presence: true
def self.request(product, exchanger)
unless product == exchanger or Offer.exists?(product, exchanger)
transaction do
create(product: product, exchanger: exchanger, status: "oczekujace")
create(product: exchanger, exchanger: product, status: "oferta")
end
end
#other methods
end
Making offers is working, because I checked it in Console.
My problem is in OffersController:
class OffersController < ApplicationController
before_filter :setup_products
def create
Offer.request(#prod, #exchanger)
redirect_to root_path
end
private
def setup_products
#prod = current_user.products.find(1)
#exchanger = Product.find_by_id(params[:id])
end
end
Problem is with a following line (using link in show-page for products with different id's than 1 works):
#prod = current_user.products.find(1)
But I don't know how to find object in Db for actual product which my show-page shows. Not only for id = 1.
I don't know how to find this object in database.
I don't know the specific answer to your question, but perhaps if I explain what you need to look at, your solution will arise:
Find
Rails isn't magic - it uses ActiveRecord (which is an ORM - Object-Relation Mapper), which means every time you fire a query (through find), your ORM (ActiveRecord) will search the relevant database data for you
The problem you have is that although you're using the correct syntax for your lookup, you may not have a record with an id of 1 in your db.
current_user.products.find(1) tells ActiveRecord to scope the query around the current user, and their products. So you'll get something like like this:
SELECT * FROM 'products' WHERE user_id = '15' AND id = '1'
Objects
Further, you have to remember that Ruby (and Rails by virtue of being built on Ruby) is an object orientated language. This means that everything you load / interact with in the language should be based on an object
The problem you have is you're not associating your object to your Rails framework correctly. What I mean here is described below, but essentially, if you build your Rails framework correctly, it will give you the ability to associate your objects with each other, allowing you to call the various products you need from your offer
This is a simplistic way of looking at it, of course. You'll want to look at this diagram to see how it works:
Bottom line - try treating your application like a series of objects, rather than a logical flow. This will help you appreciate the various associations etc that you need to get it moving forward
Resources
You mention you can't show the product on your show page for an id other than one. I think the problem is really about how to get your show action to work.
If this is the case, let me explain...
Rails is resource-based, meaning that everything you do / create needs to be centred around a resource (object) of some sort. The problem is many people don't know this, and consequently complicate their controller structure for no reason:
Above is the typical "CRUD" routing structure for Rails-based resources. This should demonstrate the way that Rails will typically be constructed -- around resources
--
Further, Rails is built on the MVC programming pattern - meaning you need to use your controller to populate a series of data objects for use in your application.
To this end, if you load a resource, and want to populate it with resourceful information of another object - you need to make sure you have set up the data objects in a way to ensure you can look them up correctly, which either means passing the data through your routes or using a persistent data-type, such as cookies or sessions
The problem you have is you need to pass the product id to your controller somehow. How I'd do that is as follows (using nested resources):
#config/routes.rb
resources :offers do
resources :products #-> domain.com/offers/2/products
end
This will give you the ability to load the products controller with the variables params[:id] for the product, and params[:offer_id] for your Offer made available:
#app/controllers/products_controller.rb
Class ProductsController < ApplicationController
def show
#offer = Offer.find params[:offer_id]
#product = Product.find params[:id]
end
end
I have a table output from entries using the rails generated scaffold: CRUD ops.
If I want to make another action on the table like the default "Show, Edit, Destory" like a library book "check in", that will update the status to "checked in"...
What would be the proper way to use the model and controller to update? (Using mongodb)
Better stated: What's the best way to have many custom actions? Think of it like many multi purpose "Facebook Likes".
On the table, list of actions "Punch this", "Check out this"...
There are lots of ways to handle this, but I typically like to isolate actions like this in their own controller action with it's own route.
Model
To keep things tidy I recommend adding a method to the model that updates the attribute you are concerned about. If you aren't concerned with validation you can use update_attribute. This method skips validations and saves to the database
class LibraryBook < ActiveRecord::Base
def check_in!
self.update_attribute(:checked_in, true)
end
end
View
You'll need to update the index.html.erb view to add the link to update the individual record. This will also require adding a route. Since you are updating the record you will want to use the PUT HTTP verb.
routes.rb
resources :library_books do
match :check_in, on: :member, via: :put # creates a route called check_in_library_book
end
index.html.erb
Add the link
link_to check_in_library_book_path(library_book), method: :put
Controller
Now you need to add the action within the controller that calls the #check_in! method.
class LibraryBooksController < ApplicationController
def check_in
#library_book = LibraryBook.find(params[:id])
if #library_book.check_in!
# Handle the success
else
# Handle the Failure
end
end
end
In my opinion, the best way to handle status workflows like this is to think about it in terms of events, and then just think of status as most recent event. I usually create an event_type table with a name and code (so, e.g. Check In and CHECK_IN for name and code, respectively), and then an event table with an event_type_id, timestamp, and usually some kind of user id, or IP address, or both.
Then you could say something like this:
class Thing < ActiveRecord::Base
has_many :events
def status
events.order("created_at DESC").first.event_type.name
end
end
There are also "audit trail" gems out there, but in my (limited) experience they aren't very good.
This doesn't speak to MongoDB, and may in fact be incompatible with Mongo, but hopefully it at least points you in the right direction or gives you some ideas.