I want to have a single view but want to render different attributes depending upon the json-api that calls it. For example: the index page does not require all the attributes, so there is no need to call all the attributes for it, while show page needs all the attributes, so it should get all the attributes.
I basically want something like:
attributes [:id, :name, :email, :website, :inserted_at, :updated_at]
for show and
attributes [:id, :name, :email]
for index.
I am using ja-serializer for this, so would like a solution in that only.
PS: I can have two different views with corresponding attributes but that seems like a workaround also doesn't make much sense.
Thanks in advance.
It would help if you post some code. But you can do this within the view. You can define separate render function heads for each controller action.
For example:
def render("index.json", %{store: store}) do
%{data: %{store: %{id: store.sap_id, name: store.name}}}
end
def render("show.json", %{store: store}) do
%{data: %{store: %{id: store.sap_id, name: store.name, other: store.other}}}
end
Above, you have a render function head for each action: index and show. The function body then builds the correct JSON response. You can use this approach to customise the attributes you want to return.
There is an optional parameter in render method call. We can specify the fields in "fields" and keep the view as it is.
def index(conn, params) do
render("index.json-api", data: data, opts: [fields: %{"table_name"=> "fields,in,csv,style"}])
end
For more, refer to Conditional attribute inclusion in
https://hexdocs.pm/ja_serializer/JaSerializer.DSL.html
Related
I want to write a method that creates a bunch of almost-duplicate records, just with one or two parameters changed. I'll make a form to control those parameters, I'm just wondering about how best to write the method, and where do keep it.
Presently in my document.rb I've written this:
def self.publish(brand, components, template)
brand.users.each do |user|
Document.create(:component_ids => components, :message => 'Message.', :template_id => template.id, :user_id => user.id)
end
end
It doesn't feel right though. Is there a better way to do this?
This code is fine if your security model allows all these fields to be bulk assignable by mention in attr_accessible in the model. If it doesn't then you're better off using the block form of create. Also, if Document, Template and User are ActiveRecord instances, you should let Rails manage the details of ids.
def self.publish(brand, components, template)
brand.users.each do |user|
Document.create do |doc|
doc.component_ids = components,
doc.message 'Message.',
doc.template = template,
doc.user = user
end
end
end
One final note is that component_ids must be serialized to store a list. This is probably a flaw in your model design. The better way is (probably) to specify Component belongs_to User and also User has_many Components. I.e. Component contains a foreign key to User. If it's necessary for a Component to belong also to many users, then you'll need either has_and_belongs_to_many or has_many ... through. The Rails guide on relations describes all this in more detail.
With the right relations set up, the code will become:
def self.publish(brand, components, template)
brand.users.each do |user|
Document.create do |doc|
doc.components = components, # Components is now a list of active records.
doc.message 'Message.',
doc.template = template,
doc.user = user
end
end
end
The resulting SQL will get all the foreign keys and (if necessary) relation tables filled in correctly.
Well, DRY! So i thought it should be easy to add a new action (like the existing new, edit) to all my controllers (in my case copy). But how do you setup a new route for ALL controllers?
Without going in to 'loops' (i.e. %w().each ...) inside the routes.rb ?
I mean, we want DRY right? So you don't want copy your action inside the routes file for each resource. I guess you should be able to extend the default actions/routes (index, new, edit,etc.) easy?
Thanks!
AFIK no way to do this by default. You could monkey-patch resources to include this functionality:
https://github.com/rails/rails/blob/b229bc70e50ec0887c5bb3aaaa9c6ee8af054026/actionpack/lib/action_dispatch/routing/mapper.rb#L982
...but my hunch is you would be better off re-considering whether this functionality can be created another way, since what you want to do is "off the Rails".
One option is create a CloneController#new that accepts a model and id and creates a clone. This seems like it would be drier, and wouldn't require you to pepper a gazillion "clone_article" "clone_blog" "clone_user" paths all over the place.
Obviously you would want to carefully white-list the models/ids that can be passed in.
Looking through the source there isn't a way to add to the default actions for a resource.
But, as #juwiley says, the methods resources :item is just a shortcut for creating a load of member and collection methods.
All you need to do is something like this
class ActionDispatch::Routing::Mapper
def resources_with_copy(*resources, &block)
block_with_copy = lambda do
block.call
member do
post :copy
end
end
resources(*resources, &block_with_copy)
end
end
Then in your routes.rb just say
resources_with_copy :items
resources_with_copy :posts do
member do
post :share
end
end
...
I'm having a problem in my Rails 3.2 app where a virtual attribute sent restfully via JSON is not in the right place in the params hash. Well, it isn't where I expect. It remains to be seen if my expectations are correct. :)
I have a model using the standard virtual attribute pattern, like this:
class Track < ActiveRecord::Base
def rating
# get logic removed for brevity
end
def rating=(value)
# set logic
end
def as_json(options={}) # so my method is in the JSON when I use respond_with/to_json
super(options.merge(methods: [:rating]))
end
end
The JSON sent to my controller looks like this:
{"id":1,"name":"Icarus - Main Theme 2","rating":2}
To be clear, name and id are not virtual, rating is.
I end up with this in the params hash, after rails does its magic:
{"id"=>"1", "name"=>"Icarus - Main Theme 2", "rating"=>2, "track"=>{"id"=>"1", "name"=>"Icarus - Main Theme 2"}}
As you can see, id and name make it to the nested :track hash, but rating does not. Is this expected behavior? It breaks the (somewhat) standard practice of using the nested hash in the controller because the nested hash does not contain all the parameters I need.
Track.update(params[:id], params[:track]) # :track is missing rating
Thanks for your help!
I recently ran into this gotcha as well. The problem is, the params wrapper is looking at your model Track.attribute_names to determine how to map the data into a :track => {params} hash. If you don't have a model associated, the default will be to wrap the params based on the controller name, and include all of the values:
class SinglesController < ApplicationController
def create
#params[:single] will contain all of your attributes as it doesn't
# have an activerecord model to look at.
#track_single = Track.new(params[:single])
end
end
You can call wrap_parameters in your controller to tell action controller what attributes to include when its wrapping your params, like so:
class TracksController < ApplicationController
wrap_parameters :track, :include => :rating
#other controller stuff below
end
See more here: http://api.rubyonrails.org/classes/ActionController/ParamsWrapper.html
Maybe if you assign the rating virtual attribute inside the nested hash like this:
def as_json(options={})
super(options.merge(:track => {:methods => #rating}))
end
It would behave the way you expected.
Just ran across this problem and figured out a pretty decent solution. Add the following to your ApplicationController
wrap_parameters exclude: [:controller, :action, :format] + ActionController::ParamsWrapper::EXCLUDE_PARAMETERS
This way, everything is nested under your resource (except for stuff Rails adds to the params hash) and you won't ever have to append to a controller specific call of wrap_parameters again. :D
For certain models, I wish to provide functionality that allows a user to create a new record with default attributes based on copy of an existing record.
I'm wondering what would be the correct restful route for this.
My initial thinking is that it could be a parameter to the new action. I.e. to borrow from the the Rails Guides examples, instead of just:
GET : /photos/new
Also allow:
GET : /photos/new/:id
...where :id is the id of the record to use as a template. The response would be a new/edit form, same as with a plain old new but the values would be pre-filled with data from the existing record. The parameter (or absense of it) could be easily handled by the new controller method.
The alternative seems to be to create a new controller method, for example copy which would also accept an id of an existing record and response with the new form as above. This seems a little 'incorrect' to me, as the record is not actually being copied until the user saves the new record (after probably editig it somewhat).
TIA...
UPDATE: my question is not "how do I do this in rails?", it's "is it RESTful?"
my question is not "how do I do this in rails?", it's "is it RESTful?"
No, it isn't. For that matter, neither is GET /photos/new. Rails seems to be hopelessly mired in the past, where it was considered haute programme for a GET on a URI to return an HTML form which would then POST x-www-form-urlencoded data back to that same URI. The opacity of that POST forces them to invent new verbs-as-URI's like /photos/new, when you could be using PUT instead, or at least POST with the same media type.
The simplest way to make a copy of an HTTP resource RESTfully is:
GET /photos/{id}/ -> [representation of a photo resource]
...make modifications to that representation as desired...
POST /photos/ <- [modified representation]
If you're implementing this for browsers, you should be able to perform those actions via Ajax quite easily, using an HTML page sitting perhaps at /photos/manager.html/ to drive the interaction with the user.
You can try to use nested resources. I'm not exactly sure about structure of you application, but in general using nested photos will look somehow like this:
routes.rb
resources :photos do
resources :photos
end
photos_controller.rb
before_filter :find_parent_photo, :only => [:new, :create]
def create
#photo = Photo.new params[:photo]
if #parent_photo.present?
# fill some #photo fields from #parent_photo
end
#photo.save
respond_with #photo
end
def find_parent_photo
#parent_photo = Photo.find(params[:photo_id]) if params[:photo_id].present?
end
new.html.haml
= form_for [#parent_photo, #photo] do |f|
-# your form code
previously when you wanted to add a link to photo creation you wrote something like that
= link_to "new photo", [:new, :photo]
now if you want to add a link to photo creation based on foto #photo1
= link_to "new photo based on other one", [:new, #photo1, :photo]
You should be able to match a route like so:
match 'photos/new/:photo_id' => 'photos#new
or you could just pass a :photo_id parameter in the url and handle it in the controller:
'/photos/new?photo_id=17'
Example using helper method: new_photo_path(:photo_id => 17)
Edit: I don't know if this conforms to REST
It may be over the top, but you could do something like this:
class PhotoCopiesController < ApplicationController
def new
#photo = Photo.find(params[:photo_id]).dup
end
def create
end
end
and
resources :photo_copies, :only => [:new, :create]
and
= link_to 'Copy', photo_copy_path(:photo_id => #photo.id)
Now i have something like this
http://myapp.com/pages/1
http://myapp.com/pages/2
http://myapp.com/pages/3
http://myapp.com/pages/4
And each page belong to one user
What i need is to each user to set it's own custom name for the page.
I was thinking of using the friendly_id gem http://norman.github.com/friendly_id/
but I don't find any method to directly edit the slug to set a custom friendly url
how should i proceed?
FriendlyID is a great gem.
It shouldn't be hard to implement user defined page URL.
Create table pages with user_id and link
class User < ActiveRecord::Base
has_many :pages
class Page < ActiveRecord::Base
belongs_to :user
has_friendly_id :link # link is name of the column whose value will be replaced by slugged value
On the page#new you add an input for the link attribute.
Alternatively, you could set friendly_id on title or something else with :use_slug => true option. This way FriendlyID will take the title and modify it so it doesn't have and restricted characters. It will use it's own table to store slugs. Use cached_slug to increase performanse.
Updated
To give users a choice whether they wan't to set a custom link, you could do this:
Set friendly_id on the link field without slugs..
Make a virtual attribute permalink so you could show it in your forms.
In the before_filter, check whether the permalink is set.
If it is, write it to the link field.
If it's not, write title to the link field.
FriendlyID uses babosa gem to generate slugs. If you decide to use it as well, this is how your filter could look like:
protected
def generate_link
#you might need to use .nil? instead
self.link = self.permalink.empty? ? make_slug(self.title) : make_slug(self.permalink)
end
def make_slug(value)
value.to_slug.normalize.to_s #you could as well use ph6py's way
end
Adding to_param method to one of the models should help:
def to_param
"#{id}-#{call_to_method_that_returns_custom_name.parameterize}"
end
Hope this is what you are looking for :)
I am not using the friendly_url gem and am not sure whether my way is efficient. But it works fine for me.
I have a model called Node with id and friendly url field called url_title.
My routes.rb file:
resource 'nodes/:url_title', :to => 'Nodes#view'
nodes_controller.rb
class NodesController <ActiveController
def view
#node = Node.find_by_url_title(:params(url_title))
end
end
And use the #node variable to populate your view.
Now, whenever I type www.example.com/nodes/awesome-title , it takes me to the proper page. One argument against this can be need to create an index on a non-primary field. But I think that might be required for better performance even in the friendly_url gem. Also, the non-primary field url_title needs to be unique. Again, this might be required even for correct working for friendly_url .
Feel free to correct me if I am wrong in these assumptions.
There are a variety of ways, you can achieve this-
1) using Stringex
2) sluggable-finder
3) friendly_id
A complete step by step methodology with reasons for each to be used can be found out here. Happy reading!