I am a beginer and I just created a welcomes controller and model welcome with title:string and name:text, and when I run to check does it work or not I get this error which I don't understand since it is very basic code! I should get at least a blank page not error!
views/welcome/index.html.erb
<h1>Welcomes#index</h1>
<%= #welcomes.each do |f| %>
<%= f.title %>
<%= f.name %>
<% end %>
controllers/welcomes/
class WelcomesController < ApplicationController
def index
#welcomes=Welcome.All
end
def show
end
def create
end
end
the error I get :
NoMethodError in WelcomesController#index
undefined method 'All' for #<Class:0x007f8bb2af5060>
class WelcomesController < ApplicationController
def index
#welcomes=Welcome.All
end
Within index action of Welcomes Controller modify:
#welcomes = Welcomes.All to
#welcomes = Welcome.all
The model name is Welcome and you are using plural of it within index action which generated the error.
Related
This is another I'm-totally-new-to-Ruby-please-have-mercy situation.
So i'm trying to figure out how to make a database of all my buttons to save the click count each time they're clicked. I started a new rails to try it out and generated a model Buttonand a controller buttons index
route.rbs
Rails.application.routes.draw do
resources :buttons
root 'buttons#index'
end
migration
class CreateButtons < ActiveRecord::Migration[5.0]
def change
create_table :buttons do |t|
t.integer :clicks
t.timestamps
end
end
end
buttons_controller
class ButtonsController < ApplicationController
def index
#button = Button.find(1)
end
def doit
#button = Button.find(1)
#newcount = #button.clicks + 1
Button.find(1).update_attributes(:clicks => #newcount)
end
end
Now.. i need to trigger the doit method.. is it possible to trigger a non CRUD operation ?
i tried this but it doesn't seem to work
index.html.erb
<h1>Hello, This is button and my click are :</h1>
<h1><%= #button.clicks %></h1>
<%= link_to 'click me', method: :doit %>
I know there's something I'm not getting here...
Ruby have been doing so much magic that I can't do a simple ruby method.. it have been really hard for me getting the part were methods are taking place without calling them by name..
Specially when I trigger a delete method and the destroy method is triggered by that.. I really need to get used to this too-much-magic coding
Several things to improve, I think. Please get back to me if something is not working (I did not run the code)
Make your index action list all the buttons
Controller:
def index
#buttons = Button.all
end
View:
<h1>These are all my buttons</h1>
<% #buttons.each do |button| %>
<%= link_to("Button #{button.id}", button_votes_path(button), method: :post) %>
<% end %>
It's common to have index show a list of resources.
Only create the routes you need, make increment a separate action
I'd chose to call it "vote". You could also call it "clicks" or "presses" or whatever.
resources :buttons, only: [:index] do
resources :votes, only: [:create]
end
Add the votes controller
class VotesController < ApplicationController
def create
button = Button.find(params[:id])
button.clicks += 1
button.save
redirect_to buttons_path
end
end
No error handling here. So this is just to get you started.
For the next steps I suggest you follow a tutorial or start with simpler stuff.
I am working on a food app in ruby on rails which requires to get calorie value of food item from food api.In my controller i am getting the JSON response but i am unable to parse and display the calorie value of food item in a index.html.erb file here is my controller code.
require 'rubygems'
require 'httparty'
class FoodsController < ApplicationController
def index
#foods = Food.all
end
def show
#food = Food.find(params[:id])
end
def new
#food = Food.new
end
def edit
#food = Food.find(params[:id])
end
def create
#food = Food.new(food_params)
#response = HTTParty.get('http://api.nutritionix.com/v1_1/search/'+#food.name+'?fields=item_name%2Citem_id%2Cbrand_name%2Cnf_serving_size_unit%2Cnf_calories%2Cnf_total_fat&appId=696d1ad4&appKey=aec2c4766d40d7f6346ed89d5d82fe75')
#http_party_json = JSON.parse(#response.body)
if #food.save
redirect_to foods_path
else
render 'new'
end
end
def update
#food = Food.find(params[:id])
if #food.update(food_params)
redirect_to #food
else
render 'edit'
end
end
def destroy
#food = Food.find(params[:id])
#food.destroy
redirect_to foods_path
end
private
def food_params
params.require(:food).permit(:name, :quantity)
end
end
Any suggestions are highly welcome as i am newbie on stackoverflow so dont know proper editing forgive please! help me how to display calorie value in html page
You can add a new function to Food model to get you the Calorie:
class Food
def calorie
response = HTTParty.get("http://api.nutritionix.com/v1_1/search/#{self.name}?fields=item_name%2Citem_id%2Cbrand_name%2Cnf_serving_size_unit%2Cnf_calories%2Cnf_total_fat&appId=696d1ad4&appKey=aec2c4766d40d7f6346ed89d5d82fe75")
json = JSON.parse(response.body)
end
end
and then simply in your index.erb if you loop over foods collection you do the following:
<% #foods.each do |food| %>
<%= food.name %>
<%= food.calorie %>
<% end %>
but in that case performance will not be good, as you do remote access for each item each time you display data, so as calorie value is always the same for same food, then after its created you can do remote query and store the calorie to calorie attribute in your Food model
You can do the following:
class Food < ActiveRecord::Base
before_create :set_calorie
private
def set_calorie
response = HTTParty.get("http://api.nutritionix.com/v1_1/search/#{self.name}?fields=item_name%2Citem_id%2Cbrand_name%2Cnf_serving_size_unit%2Cnf_calories%2Cnf_total_fat&appId=696d1ad4&appKey=aec2c4766d40d7f6346ed89d5d82fe75")
self.calorie = JSON.parse(response.body)
end
end
I'm doing the Getting started with Rails tutorial and when I run the local server from shell I get this:
`NoMethodError in Posts#new` `/_form.html.erb where line #1 raised:
`undefined method `model_name' for NilClass:Class
That is the extracted source (around line #1):
1: <%= form_for #post do |f| %>
2: <% if #post.errors.any? %>
3: <div id="errorExplanation">
4: <h2><%= pluralize(#post.errors.count, "error") %> prohibited
I just started on Ruby on Rails and I can't figure out what is happening. What am I doing wrong?
The error message, you are seeing means that you have some variable that contains a nil object instead of the actual object you expect.
While the error message doesn't explicitly reference this, it is likely your #post variable is nil.
Why is it nil? That's near impossible to say given the code here. Please post your PostsController#new action as well.
The fix is into posts_controller.rb, add next code
def new
#post = Post.new
end
Good luck
// Make sure to use model declaration inside your method to check the error logs
class PostsController < ApplicationController
def new
#post = Post.new
end
class ProfileController < ApplicationController
def show
#user = current_user
#first_name = #user.first_name
#last_name = #user.last_name
end
def settings
end
def pics
#photos = current_user.photos.all
end
end
in the view of _pics.html.erb, I have
<% #photos.each do |p| %>
<%= image_tag p.image(:medium) %>
<% end %>
If I change it to current_user.photos.each do |p|, it works, which is weird. I don't get an error from this code on my other computer.
In a comment you said, that you render the pics partial from your show view. Since the show view is rendered by the show action and the show action does not set the #photos variable, you can't use that variable. So to fix your problem, you'd need to set the variable in the show action.
You seem to think that rendering the pics partial will invoke the pics action, but that's not the case. An action will only be invoked if an URL is accessed that's mapped to that using the routing system. Rendering partials does not invoke any actions.
Also it should just be #photos = current_user.photos without the all.
To learn Rails, I am writing a simple guestbook app that does not use a database.
Anyway, this is what my view looks like:
views/guest_book_pages/home.html.erb
<h1>Guest Book</h1>
<%= #userinput %>
<%= form_for(:guestbook) do |f| %>
<%= f.label :input %>
<%= f.text_field :input %>
<%= f.submit "Sign" %>
<% end %>
And the controller looks like this:
controllers/guest_book_pages_controller.rb
class StaticPagesController < ApplicationController
def home
#userinput = params[:guestbook]["input"]
end
end
Whenever I change the "input" to a symbol :input, the application breaks and gives me a warning that says: undefined method `[]' for nil:NilClass
What is the reason for this? Why can't I use a symbol?
update: Now it won't even work with the string. What is going on?
update#2: It works with both symbols and string. The only problem is that it will not load the first time. If I can get the page to load, then either will work. How can I get the page to load?
Action use to be handle something, and render view.
when you inter home, the home action has be called, and no param posted now.
for your code, home action should just be empty, it just to render the home_page.
your handle code should move to some action like sign_in, whitch handle the form post and you can get the params.
The first time you load the page the params var is not set. It is only when you submit your form back that there are params
Try
#userinput = params[:guestbook]["input"] || ''
which will initialize the #userinput to an empty string if the params is not found
edit:
This will check if the params has the key guestbook first, then will either set the instance var userinput to an empty string or the value of [guestbook][input] if it exsists.
If all else fails, the instance var is initialized to an empty string to prevent an error in your view.
if params.has_key?(:guestbook)
#userinput = params[:guestbook]["input"] || ''
else
#userinput = ''
end