I have started a new app and I'm setting up all the basic CRUD operations. I have a Event table and I'm trying to render all the events to an index page. All I want to render is the event name and description. Right now the name and description render but so does the entire event object? That's strange to me because I'm going through each object a picking out what I want to display. I'll show my code for clarity.
VIEW:
<%= #event.each do |e| %>
<%= e.name %>
<%= e.description %>
<% end %>
CONTROLLER:
class EventsController < ApplicationController
def index
#event = Event.all
end
end
SCREENSHOT:
FYI: I'm using the rails_admin gem. Any ideas on why the entire object is rendering would be greate thanks!
You have syntax error
Just remove the <%= from your first line and only <% then problem solved.
Now you should have:
<% #event.each do |e| %>
<%= e.name %>
<%= e.description %>
<% end %>
Meaning of <%= is to print and you printed entire object.
Related
I'm new in ruby on rails, and I want to practice it.
I'm stuck when I want to include a view into antoher view.
I want by doing that to have my posts into another view than of posts/index
posts/index
method:
def index
#Posts = Post.all
end
view:
<% #posts = capture do %>
<% #posts.each do |post| %>
<h3>
<%= post.title %>
</h3>
<p>
<%= post.content %>
</p>
<% end %>
<% end %>
pages/index
<h1> Index Of another pages </h1>
<%= #posts %>
If you want to force your index action to render another view, then go with follow code:
def index
#Posts = Post.all
render 'pages/index'
end
Correct me if I haven't get you
It sounds to me like you need to save the reusable view code as a partial, and render it all places it's required.
To use a partial, save it down with an underscore prefix, i.e. _posts.html.erb.
This can then be rendered using:
<%= render 'path/to/posts' %>
You'll likely need to pass in the posts variable to the partial, as in the following:
<%= render 'path/to/posts', posts: #posts %>
And the change your view to use posts rather than #posts.
Update:
The result of capture is assigned to #posts, although this variable still wouldn't be available in another template - rather to be used again on the same page
Based on what you're saying about the project's structure, it sounds like you'd need the following:
in app/views/posts/_posts.html.web
<% #posts.each do |post| %>
<h3>
<%= post.title %>
</h3>
<p>
<%= post.content %>
</p>
<% end %>
In both controllers' index action:
#posts = Post.all
In the posts/index view:
<%= render 'posts' %>
In the pages/index view:
<%= render 'posts/posts' %>
I don't want to confuse things, but Rails has a little magic in there where -
alternatively - you can define a partial _post.html.erb as follows:
<h3>
<%= post.title %>
</h3>
<p>
<%= post.content %>
</p>
And simply call <%= render #posts %> in each view. This would be the best 'Railsy' way of doing things.
Let me know how you get on!
I'm starting on ruby on rails, first thing I want to try is modifying the "Todo app" example.
I do this by the tutorial: https://www.youtube.com/watch?v=fd1Vn-Wvy2w
After I finished, I saw that when I clicked on a todo_list, it will redirect to "show" form todo_list, but now I want the "show" display on the index with all the todo_list. I have tried to write
<%= todo_items.content %>
on the index page but it got some errors. Is there any solution or should I modify something on the Controller page so that
todo_items.content
should be able to display on the Index page
You need to load those items in your controller action first:
def index
#todo_items = TodoItem.all
end
then in index.html or whatever template you are rendering for this action you can render this collection:
<%= render #todo_items %>
that should render an todo_item partial that you should have created based on your video located at /app/views/todo_items/_todo_item.html.erb. Or you can do:
<% #todo_items.each do |item| %>
<%= item.content %>
<% end %>
In controller:
def index
#todo_lists = TodoList.all
end
in view:
<% #todo_lists.each_with_index do |list, index| %>
List <%= index + 1 %> todos:
<%= render list.todo_items %>
<% end %>
I'm trying to create a helper method that will display {user.name} has no submitted posts." on the profile show view of user if they haven't yet submitted any posts and display the number posts they have . currently on my show view i have <%= render #user.posts %> which displays nothing when there are 0 posts submitted.
the partial for post is :
<div class="media">
<%= render partial: 'votes/voter', locals: { post: post } %>
<div class="media-body">
<h4 class="media-heading">
<%= link_to post.title, topic_post_path(post.topic, post) %>
<%= render partial: "labels/list", locals: { labels: post.labels } %>
</h4>
<small>
submitted <%= time_ago_in_words(post.created_at) %> ago by <%= post.user.name %> <br>
<%= post.comments.count %> Comments
</small>
</div>
</div>
ive tried :
def no_post_submitted?(user)
user.post.count(0)
"{user.name} has not submitted any posts yet."
end
on my user show view :
<%= if no_post_submitted?(#user) %>
<%= render #user.posts %>
which im more than sure is wrong but i have no idea how to implement this method .
Where you are using render #user.posts you can just add a simple conditional:
<% if #user.posts.empty? %>
<p><%= #user.name %> has no submitted posts</p>
<% else %>
<%= render #user.posts %>
<% end %>
There wouldn't be much point creating a helper for this unless you need to use it in multiple places.
Render collection returns nil if the collection is empty so you can use the || operator:
<%= render #user.posts || "{#user.name} has not submitted any posts yet." %>
Or if there is more code render another partial:
<%= render #user.posts || render 'no_posts' %>
In Ruby methods automatically return the last value so this method:
def no_post_submitted?(user)
user.post.count(0)
"{user.name} has not submitted any posts yet."
end
Will always return a string - if you use a string literal in a condition it will be evaluated as true with the warning warning: string literal in condition. Also that is not how you use count - passing 0 will cause it to query on column 0 or just error.
http://apidock.com/rails/ActiveRecord/Calculations/ClassMethods/count
So to fix the method you would do:
def no_post_submitted?(user)
user.posts.empty?
end
However that conditional is so simple that it does not really warrant a helper method. Instead you would just write:
<%= if user.post.any? %>
<%= render #user.posts %>
<% else %>
<%= "{user.name} has not submitted any posts yet." %>
<% end %>
There are a couple of problems with your solution. Remember, rails is more about convention over configuration.
Your method no_post_submitted? should actually return true/false since its a method ending with ?. Also it should be named no_posts_submitted? for clarity. It should look something like this:
def no_post_submitted?(user)
user.posts.count > 0
end
Then, there should be another helper method that will print your required message, Something like:
def no_posts_message(user)
"{user.name} has not submitted any posts yet."
end
And eventually you can all plug it in like this:
<% if no_posts_submitted?(user) %>
<%= no_posts_message(user) %>
<% else>
<%= render #user.posts %>
<% end %>
As per the docs:
In the event that the collection is empty, render will return nil, so it should be fairly simple to provide alternative content.
<h1>Products</h1>
<%= render(#products) || "There are no products available." %>
--
So...
<%= render(#user.posts) || "#{#user.name} has not submitted any posts yet." %>
So I have an interesting problem I'm working on. I am trying to create multiple objects of the same model in one view. I would like to display all the possible objects in my view, check boxes to select which ones to create, then submit and create all the corresponding objects.
Now the objects to select are gotten using an API request and returned in JSON format. The JSON is then displayed on the view for the user to select, then an array containing all the selected objects is sent back to the controller for creation.
Here is the relevant code that I've tried so far.
objects_controller.rb
def new
#possible_objects = <api call to get objs>
#objects = []
end
def create
params[:objects].each do |obj|
# create and save obj
end
end
objects/new.html.erb
<% form_for #objects do |f| %>
<% #possible_objects.each do |api_obj| %>
<%= check_box_tag(api_obj["name"])%>
<%= api_obj["name"] %>
<% end %>
<%= f.submit %>
<% end %>
This is definitely not the right approach, as the form will not accept an empty array as a parameter. I'm not sure where else to go with this, any pointers in the right direction would be great. Thanks.
Thanks to MrYoshiji for pointing me in the right direction, this is what ended up working
objects_controller.rb
def
#possible_objects = <api call to get objs>
end
def create
params[:objects].each do |object|
new_obj = Object_Model.new( <params> )
new_obj.save
if !new_obj.save
redirect_to <path>, alert: new_obj.errors.full_messages and return
end
end
redirect_to <path>, notice: 'Successfully created.'
end
objects/new.html.erb
<%= form_tag objects_path(method: :post) do %>
<% #possible_objects.each do |api_obj| %>
<%= check_box_tag 'objects[]', api_obj %>
<%= possible_object["name"] %>
<% end %>
<%= submit_tag 'Create'%>
<% end %>
Can you try the following?
# view
<% form_tag my_objects_path(method: :post) do |f| %>
<% #possible_objects.each do |api_obj| %>
<%= check_box_tag 'objects[names][]', api_obj["name"] %>
<%= api_obj["name"] %>
<% end %>
<%= f.submit %>
<% end %>
# controller
def create
params[:objects][:names].each do |obj_name|
YourModelForObject.create(name: obj_name)
end
end
See this comment on the documentation of check_box_tag: http://apidock.com/rails/ActionView/Helpers/FormTagHelper/check_box_tag#64-Pass-id-collections-with-check-box-tags
I have a partial that needs to have some controller logic run before it can render without issue. Is there some way to associate the partial with some controller logic that is run whenever it is rendered?
For example, this is what my current code looks like:
MyDataController:
class MyDataController < ApplicationController
def view
#obj = MyData.find(params[:id])
run_logic_for_partial
end
def some_method_i_dont_know_about
#obj = MyData.find(params[:id])
# Doesn't call run_logic_for_partial
end
def run_logic_for_partial
#important_hash = {}
for item in #obj.internal_array
#important_hash[item] = "Important value"
end
end
end
view.html.erb:
Name: <%= #obj.name %>
Date: <%= #obj.date %>
<%= render :partial => "my_partial" %>
some_method_i_dont_know_about.html.erb:
Name: <%= #obj.name %>
User: <%= #obj.user %>
<%# This will fail because #important_hash isn't initialized %>
<%= render :partial => "my_partial" %>
_my_partial.html.erb:
<% for item in #obj.internal_array %>
<%= item.to_s %>: <%= #important_hash[item] %>
<% end %>
How can I make sure that run_logic_for_partial is called whenever _my_partial.html.erb is rendered, even if the method isn't explicitly called from the controller? If I can't, are there any common patterns used in Rails to deal with these kinds of situations?
You should be using a views helper for this sort of logic. If you generated your resource using rails generate, a helper file for your resource should already be in your app/helpers directory. Otherwise, you can create it yourself:
# app/helpers/my_data.rb
module MyDataHelper
def run_logic_for_partial(obj)
important_hash = {}
for item in obj.internal_array
important_hash[item] = "Important value" // you'll need to modify this keying to suit your purposes
end
important_hash
end
end
Then, in your partial, pass the object you want to operate on to your helper:
# _my_partial.html.erb
<% important_hash = run_logic_for_partial(#obj) %>
<% for item in important_hash %>
<%= item.to_s %>: <%= important_hash[item] %>
<% end %>
Or:
# app/helpers/my_data.rb
module MyDataHelper
def run_logic_for_partial(item)
# Do your logic
"Important value"
end
end
# _my_partial.html.erb
<% for item in #obj.internal_array %>
<%= item.to_s %>: <%= run_logic_for_partial(item) %>
<% end %>
EDIT:
As commented Ian Kennedy points out, this logic can also reasonably be abstracted into a convenience method in your model:
# app/models/obj.rb
def important_hash
hash = {}
for item in internal_array
important_hash[item] = "Important value"
end
hash
end
Then, you'd access the important_hash attribute in the following manner in your partial:
# _my_partial.html.erb
<% for item in #obj.important_hash %>
<%= item.to_s %>: <%= item %>
<% end %>
What you're trying to do runs against the grain of how Rails controllers/views are designed to be used. It would be better to structure things a bit differently. Why not put run_logic_for_partial into a helper, and make it take an argument (rather than implicitly working on #obj)?
To see an example of a view "helper", look here: http://guides.rubyonrails.org/getting_started.html#view-helpers