I'm trying to list a user's wanted ads in their show page when they access /users/:id.
In my controller I have:
def show
#user = User.find(params[:id])
#wanted_ads = WantedAd.where(:user_id => params[:id])
And in my show.html.erb I have:
<%= #wanted_ads %>
Binding.pry says #wanted_ads is nil. On the actual page I get #<ActiveRecord::Relation:0x007fa3b5a93408>. This is seemingly a simple thing I'm trying to do -- what am I missing?
The where function returns a ActiveRecord::Relation.
So, you can call first to get the first element, last to get the last one or all to get all elements stored in an array called #wanted_ads.
#wanted_ads = WantedAd.where(:user_id => params[:id]).all
You can then go through this array and choose the attributes you want to pass to the view for each element.
Just a tip:
You should have in your User model an ActiveRecord relation, like this:
has_many :wanted_ads
And in your WantedAd model, like this:
belongs_to :user
And with this, you have a relation of one-to-may.
Then, you can do this:
def show
#user = User.includes(:wanted_ads).find(params[:id])
end
And then, in your view:
<% #user.wanted_ads.each do |wanted_ad| %>
<%# do something %>
<% end %>
where returns a collection of objects, not just a single object. So depending on what's returned you'll want to either call first to get the single instance that ought to return, or call each to iterate over the wanted ads and display them on your page.
You're seeing an instance of ActiveRecord::Relation in pry because of the underlying query mechanism that lazy loads the results. More details can be found here.
Assuming your #wanted_ads is not nil and you want to loop through all the wanted ads...
<% #wanted_ads.each do |wanted_ad| %>
<%= wanted_ad.some_attribute_of_wanted_ad %>
<% end %>
I would also suggest you be aware of SQL injection with the following code in your controller.
#wanted_ads = WantedAd.where(:user_id => params[:id])
As it should be
#wanted_ads = WantedAd.where(":user_id => ?", params[:id])
Related
I'm building a Rails app where I have individual entries called films. I would like to display the latest entry's link on the homepage (separate controller) and I'm struggling to make it work.
My films_controller.rb is as follows (excerpt):
def show
#film = Film.find(params[:id])
end
My home_controller.rb only has the following:
def index
end
And my view file (index.html.erb) has the following:
<%= link_to #film.last.filmTitle, film_path(#film) %>
I'm getting the following error:
Couldn't find Film with 'id'=#<Film::ActiveRecord_Relation:0x007fc93f2d1fd0>
With the #film.find(params[:id]) highlighted.
Thanks!
The last method:
Find the last record (or last N records if a parameter is supplied). If no order is defined it will order by primary key.
source
You can add a #last_film instance variable in your index controller and use it in the view.
def index
#films = Film.all
#last_film = Film.last
end
and in your index.html.erb
<%= link_to #last_film.filmTitle, film_path(#last_film) %>
The index method need something, currently, it didn't connect with ActiveRecord like model or table, that's why
Couldn't find Film with 'id'=#<Film::ActiveRecord_Relation:0x007fc93f2d1fd0>
So if you need to show recent posts in the index then you could something like this
def index
#films = Film.limit(10).order(created_at: :desc) #=> or you can use id
end
it will show last 10 records, for this in the index.html.erb like this
<% #films.each do |film| %>
<%= link_to film.filmTitle, film_path(film) %>
<% end %>
In the other hand if you need to show only one post which is the last then you should modify this query like this like limit(10) to limit(1) or you can use use the last method like this
def index
#film = Film.last
#or
##films = Film.limit(1).order(created_at: :desc) #=> or you can use id
end
if you use this #film = Film.last then your index file will like this
<%= link_to #film.filmTitle, film_path(#film) %>
otherwise, you need to use each method which describes before.
So i want to create the view:
1. for normal user, to see it job app status:
def index
#users ||= current_user
#job_apps = #users.job_app
end
It works perfectly on view.
2. Trouble (job_app method undefined) : create view for admins so they can see all candidates:
def empl
#users = User.all.where(:user_type => 'candidate')
#job_apps = #users.job_app.all
end
Note : without #job_apps i can see all the users as well.
I'm going to make a bit of an educated guess here: job_app is indeed a method of the User class, but what you're dealing with in your controller's empl method is not an instance of User, but rather, an instance of ActiveRecord::Relation, which is more or less an array of User objects. User.job_app works because job_app is a member of User, but not of ActiveRecord::Relation.
To achieve what you want, you have to do some iterating through the elements of that array within the view associated with your empl method.
controller code:
def empl
#users = User.all.where(:user_type => 'candidate')
end
view code:
<% #users.each do | user | %>
<%= user.job_app %>
<% end %>
I am stuck on what seems should have a very simple solution, but I can not find anything that will work! I am iterating results from a table on the index page (which returns a list of states). This works without any problems when multiple records are returned. However, when a single record is returned, I get an error: undefined method 'each' for #
I know it is causing the error when only one record is returned, but I can not find any documentation on how to handle this, especially in the case that 1 or 0 records could be returned.
Code in controller:
#states = State.find(params[:id])
Code in index page:
<ul>
<% #states.each do |state| %>
<li>
<%= state.state_name %>
</li>
<% end %>
</ul>
Because you're using find, when you send multiple ids in the params, multiple records are matched; when you send a single id, a single instance is returned.
To ensure that each time, you get an ActiveRecord::Relation object that you can call each on, change your controller code to the following:
#states = State.where(id: params[:id]) # index action
You mentioned that it is the index view, so the above change should solve your problem.
If it's the show view, then you need to stick with find and change your view to display only one state.
You need to check if it responds to .each, which is the prime given for knowing if something implements the enumerable module.
if #states.respond_to?(:each)
# iteration goes here
else
# single handling goes here
Ofcourse you can also use the .where option in your query which returns always a collection
#states = State.where(id: params[:id])
Scenario 1:-
When record is queried in controller as:
#states = State.find(params[:id])
Then in view it should be like that:
<p><%= #states.state_name %></p>
Scenario 2:-
When record is queried in controller as:
#states = State.all
Then in view it should be like that:
<ul>
<% #states.each do |state| %>
<li>
<%= state.state_name %>
</li>
<% end %>
</ul>
Note:- In first scenario it is only one object but in second scenario it is a collection of object or a array of object. And only array are iterated.
I have a loop in my view:
<% #deals.each do |d| %>
<% end %>
Deal and ListItem share the :code attribute.
If I wanted to count all the list_items that shared :code with a certain deal, how can I do this in the controller while iterating through the loop?
I understand it's bad form to access Models in the view correct? So that would rule out doing something like this in the loop right?:
<%= "#{ListItem.where(:code => d.code).count}" %>
Can I use a variable or some custom method to achieve this? Please let me know if I can clarify. Thank you!
You want to do all the calculation on the server in your controller action before rendering the view.
So in addition to gathering the #deals, you will also set an instance variable for the count.
def index
#deals = Deals.all # or whatever your finder is
#common_listitem_count = ListItem.where(code: #deals.pluck(:code)).count
end
Then just call the count instance variable in the view:
<%= #common_listitem_count %>
I have a users table. It contains a field "user_type".
I added the following scope stmts to the user.rb file:
scope :uemployee, where(:user_type => 'employee')
scope :uclient, where(:user_type => 'client')
scope :ucontractor, where(:user_type => 'contractor')
I created a view and I would like it to list he employees.
Here is the code I'm trying to use:
<% #users.uemployee.each do |user| %>
But, I get "undefined method `uemployee' for nil:NilClass"
What am I doing wrong?
Thanks
Looks like you wanted to do this:
<% User.uemployee.each do |user| %>
But this is considered to be a bad practice. You have to prepare you data in a controller and a view just cycles through it:
# in a controller's action
#users = User.uemployee
#in a view
<% #users.uemployee.each do |user| %>
But even this isn't the best approach. If you create the file views/users/_user.html.erb which shows the info about a particular user (current user will be available as a simple user variable, without the #) then you can simply write:
# in a view
<%= render #users %>
# remember, #users variable was set in your controller
then Rails will cycle through all the users "inside" the #users variable and show them one-by-one.
Your #users collection is nil