In my ruby on rails project, I have a share model which stores share basic values like share name, market cap, current value, book value etc. In rails, when I want to create a new share record, instead of user entering the details, I want them to enter a URL from a financial website and I want my code to read the share basic parameters from the financial website. URL is not stored in the database.
for example: If the user enters http://www.moneycontrol.com/india/stockpricequote/food-processing/nestleindia/NI. My code should read below parameters and store it in database.
name: Nestle , price: 5628, market cap: 54,366.89, book value: 352.69 etc
I read webpages using Nokogiri. And since reading from web takes time, I have to use delayed_job as well.
My new.html.erb has only one input which is URL which sends a post request to "create" action. Now URL is not part of my model. I have declared a :url parameter inside the model as below:
class Share < ActiveRecord::Base
attr_accessor :url
end
Now I am bit confused as to how to handle this url in my model/controller. Which is the best place to implement URL reading method? is it controller or model?
If I pass the url to model, how to implement the method to get url and read the parameters?
If I read the parameters in controller, how do I pass them to model?
I am not able to access the url parameter inside my controller as well. When I call my method to readthe webpage, I get an error saying, empty url is passed:
My new.html.erb:
<%= form_for(#share) do |f| %>
<p>
<%= f.label :url %>
<%= f.text_field :url, autofocus: true %>
</p>
<p>
<%= f.submit 'Pull the data'%>
</p>
<% end %>
and my current create method in my controller:
def create
#url = params[:url]
#readShareBasic(url) is a method to read the website and return a hash
#share = Share.new(readShareBasic(url)).permit(:name, :current_price, :year_low, :year_high, :current_PE_ratio, :market_cap, :book_value, :description, :price_to_book_value))
redirect_to shares_url
end
Here in controller, I am not able to access the content of params[:url] either.
thanks in advance
Use the controller create method to get the url and create/save a new share instance. You don't need the accessor in the model. If you look in the source code of your form, you'll see how the form data is being passed.
In the controller, its better to separate the strong params into its own method.
def
#url = params[:share][:url]
#share = Share.new(share_params)
#share_details = readShareBasic(#url)
# assign values from readShareBasic to the share instance as needed
# save share
end
private
def share_params
params.require(:share).permit(:name, :current_price, :year_low, :year_high, :current_PE_ratio, :market_cap, :book_value, :description, :price_to_book_value, :url)
end
Related
Newbie Here!
I'm unsuccessfully trying to submit a form of a nested model.
Aim:
Verify a translation by submitting a boolean to a reviews model to associate whether a translation is verified or not, with translation entry and user model associated references.
# routes.rb
resources :entries do
resources :reviews
end
# entry.rb
belongs_to :user
has_one :review
accepts_nested_attributes_for :review
# user.rb
has_many :entries
has_many :reviews
# review.rb
belongs_to :user
belongs_to :entry
From entry index, pass the entry instance to partial, works perfect
# /entries/index.html.erb
<% #entries.each do |entry| %>
...
<%= render 'reviews/new', entry: entry %>
...
<% end %>
Unsuccessfully setting up new/create form.
What happens is that the entry instance is well received, but I am failing to create a new model instance for review belonging to entry.
entry.review raises an nil error for review, while entry is fine when testing through browser console
First argument in form cannot contain nil or be empty
# reviews/_new.html.erb
<span>
<%= form_for entry.review do |f| %>
<div class="form-check form-switch">
<%= f.check_box :verified, class: "form-check-input" %>
</div>
<%= f.submit class: "btn btn-primary"%>
<% end %>
</span>
Another attempt was also to use just #review from the controller but that doesn't obey nested routes.
My controller looks like this
# reviews_controller.rb
def create
#entry = Entry.find(params[:entry_id])
#review = #entry.review.build(review_params)
#review.user_id = current_user.id
#review.save
end
private
def review_params
params.require(:review).permit(:verified, user: current_user, entry: #entry)
end
Am I suppose to implement my actions in the entries_controller?
I have also found the tutorial here useful but replication was unsuccessful.
Another StackOverflow reference here
I still get the error entry.review.build that review is nil.
First argument in form cannot contain nil or be empty
When building an associated record over a has_one relation, instead of
#review = entry.review.build(review_params)
you need to use the following:
#review = entry.build_review(review_params)
See the documentation for more details.
Am I suppose to implement my actions in the entries_controller?
It depends on what you're after. If you have a dedicated form for adding a new review and it is not embedded in another form for creating or updating an entry then implementing a create action in ReviewsController is the straightforward solution – in this case you should also not need accepts_nested_attributes_for in Entry.
If, however, you want to be able to create or update an entry as well as its review using the same form, then you should nest the review form in the form of the entry, keep accepts_nested_attributes_for, and use actions in EntriesController. The documentation should get you started there.
I'm fairly new to Rails and learning to create a blog using this tutorial. On step 10, once I define create and show, after creating a new post in browser I don't see any entries on show with id page. All I see is heading and and blank title and post header.
Following is my controller -
class PostController < ApplicationController
def index
end
def new
end
def create
#post = Post.new(params[:posts])
#post.save
redirect_to #post
end
def show
#post = Post.find(params[:id])
end
end
Show view ---
<h1>Show a post</h1>
<p>
<strong>Title:</strong>
<%= #post.title %>
</p>
<p>
<strong>Text:</strong>
<%= #post.text %>
</p>
Route ---
RailsBlog::Application.routes.draw do
resources :post
root :to => "post#index"
end
Form ---
<%= form_for :post, url: {action: 'create'} do |f| %>
<p>
<%= f.label :title %><br>
<%= f.text_field :title %>
</p>
<p>
<%= f.label :text %><br>
<%= f.text_area :text %>
</p>
<p>
<%= f.submit 'Submit' %>
</p>
<% end %>
May be this is just a spelling mistake, but since I've recently started learning Rails, I'm unable to resolve this.
Update: I can go to particular id using
http://localhost:3000/post/1
but am only seeing blank page with view headers
The problem is here:
#post = Post.new(params[:posts])
It should be params[:post] - singular, not plural.
Also note that the best practice with form_for is to pass an object instead of symbol:
form_for #post do |f|
Then:
You don't need to specify url
You can reuse the same form for an edit action or create action (if object creation failed due to failing validation)
This however requires to initialize new object in your new action:
def new
#post = Post.new
end
UPDATE:
Also your routes are incorrect. When defining plural resources, you need to use plural form (it's more the convention than requirement, but since you're learning stick with it). So change your routes to:
resources :posts
And rename your controller to PostsController (remember to rename file name as well). restart the server and all should work.
ANOTHER UPDATE:
You also need to rename folder app/views/post to app/view/posts.
AND YET ANOTHER UPDATE:
In rails 4, you are not allowed to mass assign any params which has not been whitelisted using strong parameters. You need to tell rails which fields you allow to be assigned first - this is a security thing. You need to make some changes to your controller:
class PostsController < ApplicationController
...
def create
#post = Post.new(post_params)
...
end
...
private
def post_params
params.require(:post).permit(:title, :text)
end
end
This is the way to tell your controller that you are expecting those attributes from your form and they can be safely assigned.
I had just similar problem on the same tutorial.
The code spelling was correct and clearly accorded to examples in tutorial and BroiSatse's answer above.
The mistake was in order of private method definition.
How it was:
...
private
def post_params
params.require(:post).permit(:title, :text)
end
def show
#post = Post.find(params[:id])
end
...
The working order:
def show
#post = Post.find(params[:id])
end
private
...
Anyway, this topic was rather helpful. Thak you for your answers!
Let's say I have book model, book.rb
class Book
include Mongoid::Document
field :book_id, type: String
field :title, type: String
end
(Here I'm using mongoid, but I think for this question it doesn't matter what type of data is.)
The book model has its own controller, views, etc.
Now, I want to create a page with form_tag (let me know if this is not a proper way), where by entering book's id and clicking enter I'll be able to remove the record this this given id from the database.
remove.html.erb:
<%= form_tag books_path, :method => 'get' do %>
<p>book_id:
<%= text_field_tag :book_id, params[:book_id] %>
<%= submit_tag "Remove", :name => nil, :confirm => "Are you sure?" %>
</p>
<% end %>
I know how to remove a given document, but can't figure out how to pass the value entered in the form and where to put the logic that will remove document.
First things first. Why do you need to store a book_id for your Book model ? Mongoid already provide a _id field for this purpose.
The usual way to destroy resources is to hit the destroy action in your controller by making a DELETE HTTP request.
class BooksController
def destroy
Book.find(params[:id]).destroy
redirect_to :back
end
end
Then simply do a link with the following:
link_to "Delete", book_path(#book), method: :delete
Where #book is your book instance.
I've just started "Build Your Own Ruby on Rails" and I have had to use Google a lot, as the book seems to have a bunch of places where the code just doesn't work. This time, I couldn't find an answer. Okay, so here's the deal. I have a form that looks like this:
new.html.erb:
<%= form_for :story do |f| %>
<p>
name:<br />
<%= f.text_field :name %>
</p>
<p>
link: <br />
<%= f.text_field :link %>
</p>
<p>
<%= submit_tag %>
</p>
<% end %>
It shows up fine when I go to localhost:3000/story/new. The thing is, when I try to type stuff into the form and press "submit," I get this error:
Routing Error
No route matches [POST] "/story/new"
My routes.rb looks like this:
FirstApp::Application.routes.draw do
resources :story
story_controller looks like this:
def new
#story = Story.new(params[:story])
if request.post?
#story.save
end
end
The story_controller stuff for new is straight out of the book. I thought I might have had a solution here, but no dice. Any help would be greatly appreciated.
I'm guessing you meant (note the at sign):
<%= form_for #story do |f| %>
That'll probably take care of your routing issue, but as John mentions, your controller action is a bit off, too. The new action should only load a dummy model and display the new.html.erb page - the saving should take place in a separate action, called create.
Hope this helps!
Edit: Minimal controller code:
class StoriesController < ApplicationController
def new
#Make a dummy story so any default fields are filled correctly...
#story = Story.new
end
def create
#story = Story.new(params[:story])
if(#story.save)
#Saved successfully; go to the index (or wherever)...
redirect_to :action => :index
else
#Validation failed; show the "new" form again...
render :action => :new
end
end
end
First off, Rails is relies on convention over configuration when using singular vs plural names. If you want to follow convention, you have to change the line in your routes.rb to resources :stories, which would generate following routes:
stories GET /stories(.:format) stories#index
POST /stories(.:format) stories#create
new_story GET /stories/new(.:format) stories#new
edit_story GET /stories/:id/edit(.:format) stories#edit
story GET /stories/:id(.:format) stories#show
PUT /stories/:id(.:format) stories#update
DELETE /stories/:id(.:format) stories#destroy
Note, that in this case you would have to rename your controller to StoriesController. However, your routes.rb has resources :story, which generates following routes:
story_index GET /story(.:format) story#index
POST /story(.:format) story#create
new_story GET /story/new(.:format) story#new
edit_story GET /story/:id/edit(.:format) story#edit
story GET /story/:id(.:format) story#show
PUT /story/:id(.:format) story#update
DELETE /story/:id(.:format) story#destroy
As you can see, indeed, there is no route for POST /story/new. I guess, the error that you are getting is triggered by following code in your controller:
if request.post?
#story.save
end
It is quite wrong, because you trying to check for POST request inside the action that is routed to by GET. Just remove this code from your new action and add create action to your StoryController like this:
def create
#story = params[:story]
if #story.save
redirect_to #story, notice: "Story created"
else
render action: "new"
end
end
This should resolve your issue for now. But I strongly recommend using plural stories for your resources, since it will be back to haunt you again.
This is the part that you (and me) have missed from the guide:
There's one problem with this form though. If you inspect the HTML
that is generated, by viewing the source of the page, you will see
that the action attribute for the form is pointing at /articles/new.
This is a problem because this route goes to the very page that you're
on right at the moment, and that route should only be used to display
the form for a new article.
The form needs to use a different URL in order to go somewhere else.
This can be done quite simply with the :url option of form_for.
Typically in Rails, the action that is used for new form submissions
like this is called "create", and so the form should be pointed to
that action.
Edit the form_for line inside app/views/articles/new.html.erb to look like this:
<%= form_for :story, url: stories_path do |f| %>
I'm new to Rails and having a hard time figuring out how to create a form that submits over Ajax without having a corresponding model object.
My use case is a simple form that collects an email address and sends it an email; there's nothing to be persisted, so no model.
In cases where I do have a model, I've had success with form_for(#model, remote: true). I can't seem to find the right helper for the case where there is no model. I tried form_tag(named_path, remote: true) and that works, but does not use Ajax.
Pointers to an example with an example with a proper controller, .html.erb and routes.rb would be really appreciated.
Here's how I solved it. The key was using form_tag and specifying a hash with an argument that properly matched my route. For my business logic, I need to pass in an "id" param, which is used in the controller logic.
<%= form_tag(sendmail_path({ id: 1}), remote: true) do %>
<%= text_field_tag :email, params[:email] %>
<%= submit_tag "Send", remote:true %>
<% end %>
routes.rb:
MyApp::Application.routes.draw do
post '/sendmail/:id(.:format)' => 'mycontroller#sendmail', :as => 'sendmail'
# etc...
end
I also had to supply a sendemail.js.erb template which updates the form after submission.