On my landing_pages "show" page, I'm trying to show the leads that came in via that page and sort them via their "score".
My landing_page model has:
has_many :page_leads
My page_lead model has:
belongs_to :landing_page
In my index method within my page_leads controller, I have this, which works:
def index
#page_leads = PageLead.order(score: :desc)
end
I try to duplicate this in the landing_pages controller for the show method. Here is what I have:
def show
#landingpage = LandingPage.find(params[:id]).order(score: :desc)
end
When I try to go to the "Show" page, I get an error "undefined method `order' for "1":String". How can I get this to work?
My show page has the following code:
<tbody>
<% #landingpage.page_leads.each do |page_lead| %>
<tr>
<td><%= page_lead.fname %></td>
<td><%= page_lead.lname %></td>
<td><%= page_lead.score %></td>
</tr>
<% end %>
</tbody>
It is just:
def show
#landingpage = LandingPage.find(params[:id])
end
Cause find returns the LandingPage with id == params[:id]. No need to sort a single item.
find returns an array or records if the params[:id] is an array.. the order can't be applied to the array, because order isn't part of the array class.
If params[:id] is a single element then the find returns the record. Again order doesn't apply, because it's just one record not a container of records..
If you want an sorted list then use
LandingPage.where(id: params[:id]).order
But since this is in the show I suspect you want the single item... As spickermann said drop the order
LandingPage.find(params[:id])
If you want to sort Page Leads, you would do something like
def show
#landingpage = LandingPage.find(params[:id])
#page_leads = #landingpage.page_leads.order(score: :desc)
end
As #spickermann mentioned, .find() only returns one model instance. You can't order this using ActiveRecord query methods.
If you want to order the page leads, you have to call .order on the set of page_leads that belong to the landing page
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.
The run down. A person can have many bids, this particular person only has one bid.
In my index action I have #bids = Bid.find_by_person_id(params[:person_id])
in my view I do
<% #bids.each do |bid| %>
<%= bid.bid_amount %>
<% end %>
I am getting NoMethodError: undefined method each' for #<Bid:0x007f988a346f00> when visting the index view for person bids.
Is this because this person only has one bid? I feel thats not the case, but other than that im at a loss..
find_by returns the first item. I think you are looking for
Bid.where(person_id: params[:person_id])
Austio's answer is correct.
However, why are you calling the Bid model directly?...
A person can have many bids
You're obviously constructing data from the person model, so why not call the following:
#person = Person.find params[:person_id]
#bids = #person.bids #-> bids belong to #person
This will build the collection without calling where.
Of course, your method only uses a single db query. But even still, the above is much more intuitive.
--
As an aside, you'll also want to use a conditional before your loop:
<% if #bids.any? %>
<% #bids.each.... %>
<% end %>
Having one bid is fine, but having none will cause the loop to spit out an error. The above resolves that issue.
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.
In my web application the user can select certain instances of an entity. For instance on the class BubbleGum, now the user can select certain instances of BubbleGum by adressing their identifier:
gums/details?show=3532667
Now, in addition I also want to make it possible to display all BubbleGums. For this I have introduced the convention of using * to identify all
gums/details?show=*
This works nice so far, but often I have to add a bit code to process the * selection. Is there a nice way to represent an all-instances object in Ruby and/or Rails?
I have thought of using simply a dedicated symbol, constants, or an actual object of the class BubbleGum that represents all the other bubble gums.
To display all the entities in a rails application generally we use a index page.
bubble_gums_controller.rb
def index
#bubble_gums = BubbleGum.all
end
views/bubble_gums/index.html.erb
<% #bubble_gums.each do |bubble_gum| %>
<tr>
<td><%= bubble_gum.name %></td>
<td><%= bubble_gum.price %></td>
</tr>
<% end %>
Refer this for further details.
http://guides.rubyonrails.org/getting_started.html#listing-all-posts
I think you want to use the query string param show.
So, you can try in your gums controller:
def details
if params[:show] == "*"
#bubble_gums = BubbleGum.all
# ...
elsif params[:show]
#bubble_gum = BubbleGum.find(params[:show])
# ...
else
render :status => 404
end
end
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])