How to display values from a database on a page for display, I do not try how much I get this error.
undefined method `email' for nil:NilClass
development.erb.html
<% #development.each do |developer| %>
<p><% #developer.email %></p>
<% end %>
welcome_controller.rb
class WelcomeController < ApplicationController
def index
#development = TeamMember.all
end
end
model.rb
class TeamMember < ApplicationRecord
end
db schema.rb
create_table "team_members", force: :cascade do |t|
t.string "email"
t.string "first_name"
t.string "last_name"
t.string "team_text"
t.string "image_url"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
It should be <%= developer.email %> instead of <% #developer.email %>
Try to change the file name inside the welcome folder to index.html.erb instead of development.erb.html
You should change your .erb file to:
<% #development.each do |developer| %>
<p><%= developer.email %></p>
<% end %>
When you use <% %> to run ruby code inline, it won't output the result (ideal for .each), however when you want the resulting value (the developer's email) to be output into the HTML, you should use <%= %>.
In addition, the file should be found at /views/welcome/index.erb.html
Hope this helps.
Related
I was building a rails app. I want to all post on a page. I am able to show posts title and body but i am not able users name(to whom post belongs -owner of post).
Post-Model
class Post < ApplicationRecord
belongs_to :user
end
User-Model
class User < ApplicationRecord
has_many :posts
end
Posts-Controller
class PostsController < ApplicationController
def index
#posts = Post.all
end
end
Posts-View index.html.erb
<h1> All article </h1>
<% #posts.each do |post| %>
<ul>
<div class="row">
<div class="col-md-offset-3 col-md-5">
<h5><b><%= post.title %></b> by <%= %></h5>
<p><%= post.body %></p>
</div>
</div>
</ul>
<% end %>
Schema looks like
create_table "posts", force: :cascade do |t|
t.string "title"
t.text "body"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.integer "user_id"
end
create_table "users", force: :cascade do |t|
t.string "name"
t.string "email"
t.string "password_digest"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
Display name of user who posted that post
Since you have a relation to the User in the Post as belongs_to :user, So, you can simply use post.user.name to get the name of the user like.
<h1> All article </h1>
<% #posts.each do |post| %>
<ul>
<div class="row">
<div class="col-md-offset-3 col-md-5">
<h5><b><%= post.title %></b> by <%= post.user.name %></h5>
<p><%= post.body %></p>
</div>
</div>
</ul>
<% end %>
bonus
If you want to eager load the user in a single query you might wanna use. Post.includes(:user).all, its better if you always use the user, saves you extra query. Mind that it has some downsides to it as well.
Try post.user to get user object. Then you can print any attribute from the user object.
<p><%= post.user.name %></p>
And use includes method to avoid N + 1 queries problem.
def index
#posts = Post.includes(:user)
end
Reference: https://guides.rubyonrails.org/active_record_querying.html
It's quite easy to access. Try post.user.name and you will get name of associated user.
Read here about all standard methods available for belongs_to association
https://guides.rubyonrails.org/association_basics.html#methods-added-by-belongs-to
UPDATE: Problem solved, thanks to Sebastian and Gabriel for the helpful pointers.
The relevant changes to my code are as follows:
app/controllers/pomodoro_cycles_controller.rb
def pomodoro_collections
{
pomodoro_collection_0: Pomodoro.offset(0).first(100),
pomodoro_collection_1: Pomodoro.offset(100).first(100)
}
end
app/views/pomodoro_cycles/show.html.erb
<% #pomodoros_collections.each do |pomodoros_collection_hash| %>
<h2><%= pomodoros_collection_hash[0] %></h2>
<% pomodoros_collection_hash[1].each do |pomodoro| %>
<p>
<%= pomodoro.id %>
<%= pomodoro.color %>
</p>
<% end %>
<% end %>
NOTA BENE:
The #first method in ActiveRecord returns an Array, so the keys in my original Hash were nested Arrays. Instead, the following was sufficient to return an Array of Pomodoro objects:
Pomodoro.offset(0).first(100)
DESCRIPTION OF ORIGINAL PROBLEM
Rails 5, PostgreSQL
PROBLEM: I cannot access Pomodoro.all from within PomodoroCycleController
I have two scaffolds: Pomodoro and PomodoroCycle, and I want to access the full list of Pomodoros within the PomdoroCycle controller.
The following code is kept simple, in order to make as clear as possible what I'm trying to do. If I can do these things, then I'll be able to do much more, but one step at a time.
Regarding the db migration files, I have already run bundle exec rails db:migrate
I want to display a full list of Pomodoros in the PomodoroCycle Show View (later to be displayed in Index), but I don't know what is missing.
From app/controllers/pomodoro_cycles_controller.rb
def show
#pomodoros_collections = pomodoro_collections
end
def pomodoro_collections
{
pomodoro_collection_0 => [Pomodoro.offset(0).first(100)],
pomodoro_collection_1 => [Pomodoro.offset(100).first(100)]
}
end
From app/views/pomodoro_cycles/show.html.erb
<% #pomodoros_collections.each do |collection| %>
<p><%= collection %></p>
<% end %>
However, this displays nothing in the browser.
app/models/pomodoro_cycle.rb
class PomodoroCycle < ApplicationRecord
has_many :pomodoros
end
app/models/pomodoro.rb
class Pomodoro < ApplicationRecord
belongs_to :pomodoro_cycle
end
Updated db/migrate/20180103032759_create_pomodoro_cycles.rb:
class CreatePomodoroCycles < ActiveRecord::Migration[5.1]
def change
create_table :pomodoro_cycles do |t|
t.string :activity
t.integer :iteration
t.integer :matrix_side_length
t.datetime :created_at
t.datetime :completed_at
t.string :category_labels, array:true, default: []
t.string :category_colors, array:true, default: []
t.string :username
t.timestamps
end
create table :pomodoros do |t|
t.belongs_to :pomodoro_cycle, index: true
t.datetime :completed_at
t.timestamps
end
add_index :pomodoros, :pomodoro_cycle_id
end
end
Untouched db/migrate/20180103054425_create_pomodoros.rb
class CreatePomodoros < ActiveRecord::Migration[5.1]
def change
create_table :pomodoros do |t|
t.boolean :status
t.string :category
t.string :color
t.datetime :completed_at
t.string :username
t.timestamps
end
end
end
First of all, as #SebastianPalma pointed out in the comments, the syntax is wrong
def pomodoro_collections
{
pomodoro_collection_0 => [Pomodoro.offset(0).first(100)],
pomodoro_collection_1 => [Pomodoro.offset(100).first(100)]
}
end
should be:
def pomodoro_collections
{
pomodoro_collection_0: [Pomodoro.offset(0).first(100)],
pomodoro_collection_1: [Pomodoro.offset(100).first(100)]
}
end
Make the keys in the hash symbols
Then to display each Pomodoro put something like:
<% #pomodoros_collections.each do |pomodoros_collection_hash| %>
<h2><%= pomodoros_collection_hash[0] %></h2>
<% pomodoros_collection_hash[1].each do |pomodoro| %>
<p><%= pomodoro.id %></p> #Or the attribute you want to display
<% end %>
<% end %>
Hope this help
I have two models: project and todo. Project has many todos.
So I wanna create a form, where I select project category from the combobox and then I add a todo to it.
For instance:
I have following categories: family, work, study.
In form in the combobox I select 'study', and then in textfield I spell a todo like 'make homework for monday' and press submit button.
project.rb
class Project < ActiveRecord::Base
has_many :todos
end
todo.rb
class Todo < ActiveRecord::Base
belongs_to :project
end
my data schema:
create_table "projects", force: :cascade do |t|
t.string "title"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "todos", force: :cascade do |t|
t.string "text"
t.boolean "isCompleted"
t.integer "project_id"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
_form.html.erb
<%= form_for #project do |f| %>
<div class="form_control">
<%= f.select :title, options_for_select([["Work", "w"],
["Family", "f"],
["Study", "f"],
["TheRest", "t"]]) %>
</div>
<div class="form_control">
*** HERE I NEED TO FIGURE OUT HOW TO ADD SOME DATA TO todo.text ***
</div>
<div class="form_control">
<%= f.submit 'Add' %>
</div>
<% end %>
this is how I show all the projects with their todos:
<% #projects.each do |project| %>
<h2> <%= project.title %> </h2>
<% project.todos.all.each do |todo| %>
<p><%= todo.text %> <%= check_box('tag', todo.__id__, {checked: todo.isCompleted}) %></p>
<% end %>
<% end %>
GitHub link : https://github.com/NanoBreaker/taskmanager
In your todo form, you could have a select box to choose the project the todo belongs to:
# todos/_todo_form.html.erb
<%= select_tag "project_id", options_for_select(Project.pluck(:title, :id)) %>
And in your todos_controller create action:
def create
#project = Project.find(params[:project_id])
#todo = #project.todos.new(todo_params)
if #todo.save
# success
else
# error
end
end
finally, permit the project_id in todo_params:
def todo_params
params.require(:todo).permit(:text, :project_id) # add any other attributes you want
end
I'm new to Rails.
I use devise for authentication in my Rails 5.0.1 project.
# Here is my Helper Module
module CategoriesHelper
def categories_for_select
Category.all.collect { |m| [m.name] }
end
end
in _form.html.erb page
<div class="field">
<%= f.label :category_name %>
<%= f.select(:category_name, categories_for_select, :prompt => 'Select') %>
<%= link_to 'Create New Category', new_category_path %>
How can I list all the items from the Category table to a drop-down list that is associated with the current_user.
UPDATE:
Schema
create_table "categories", force: :cascade do |t|
t.string "name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "user_id"
end
Assuming your User has_many categories, you can simply do:
current_user.categories.pluck(:name)
How to access customer's name from Customer table onto my Order's action view index. And vice versa.
I am getting this error:
NoMethodError in Customers#index.
Undefined method `order' for #Customer:0x24f4...
class Customer < ActiveRecord::Base
has_many :orders, foreign_key: "customer_id"
end
class Order < ActiveRecord::Base
belongs_to :customer
end
In my migration:
create_table "customers", force: :cascade do |t|
t.string "name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
create_table "orders", force: :cascade do |t|
t.integer "customer_id"
t.datetime "orderdate"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end
add_index "orders", ["customer_id"], name: "index_orders_on_customer_id", using: :btree
end
In customer's index.html.erb
<% #customers.each do |customer| %>
<%= customer.name %>
<%= customer.order.orderdate %>
<% end %>
In orders's index.html.erb
<% #orders.each do |order| %>
<%= order.orderdate %>
<%= order.customer.name %>
<% end %>
you have has many relation with customer and order so
In customer's index.html.erb
<% #customers.each do |customer| %>
<%= customer.name %>
<!-- this will display customers all order and fetch first and then show that order's orderdate -->
<%= customer.orders.first.orderdate %>
<% end %>
Try a different approach to setting the relationships between your models in the migration:
t.belongs_to :customer, index: true
See http://guides.rubyonrails.org/association_basics.html#the-belongs-to-association