I recently modified my Sessions.rb controller as it was fighting against the Devise Sessions controller for supremacy in my application. It seems to have worked out well. I modified my route.rb as mentioned in the answer.
Now I'm having a couple of issues in the default (without much changes since the scaffold) sessions forms.
config/routes.rb
namespace :classroom do
resources :registrations
resources :sessions
end
classroom/sessions/index.html.erb
<h1>Listing sessions</h1>
<table>
<tr>
<th>Class size</th>
<th>Course</th>
<th>Description</th>
<th>Location</th>
<th>Name</th>
<th>Price</th>
<th></th>
<th></th>
<th></th>
</tr>
<% #sessions.each do |session| %>
<tr>
<td><%= session.class_size %></td>
<td><%= session.course_id %></td>
<td><%= session.description %></td>
<td><%= session.location_id %></td>
<td><%= session.name %></td>
<td><%= session.price %></td>
<td><%= link_to 'Show', session %></td>
<td><%= link_to 'Edit', edit_classroom_session_path(session) %></td>
<td><%= link_to 'Destroy', session, method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
</table>
<br />
<%= link_to 'New Session', new_classroom_session_path %>
The following links has stopped working and gives a "Could not find a valid mapping for" error message when loading /sessions/index.html.erb
<td><%= link_to 'Show', session %></td>
td><%= link_to 'Edit', edit_classroom_session_path(session) %></td>
<td><%= link_to 'Destroy', session, method: :delete, data: { confirm: 'Are you sure?' } %></td>
Output of running rake routes:
classroom_sessions GET /classroom/sessions(.:format) classroom/sessions#index
POST /classroom/sessions(.:format) classroom/sessions#create
new_classroom_session GET /classroom/sessions/new(.:format) classroom/sessions#new
edit_classroom_session GET /classroom/sessions/:id/edit(.:format) classroom/sessions#edit
classroom_session GET /classroom/sessions/:id(.:format) classroom/sessions#show
PUT /classroom/sessions/:id(.:format) classroom/sessions#update
DELETE /classroom/sessions/:id(.:format) classroom/sessions#destroy
I'm not too sure how to modify the 'Show' and 'Destroy' part of the link to make them work with the new namespace. Thanks in advance for any help. Much, much appreciated.
Thanks,
Francis
try with:
<td><%= link_to 'Show', classroom_session_path(session) %></td>
<td><%= link_to 'Edit', edit_classroom_session_path(session) %></td>
<td><%= link_to 'Destroy', classroom_session_path(session), method: :delete, data: { confirm: 'Are you sure?' } %></td>
Look at here at a nice answer how to handle links with namespaced routes:
rails using link_to with namespaced routes
The name of the route is presented on the first column of the routes table. You should follow it on the link helper.
They should be:
<td><%= link_to 'Show', classroom_session_path(session) %></td>
<td><%= link_to 'Edit', edit_classroom_session_path(session) %></td>
<td><%= link_to 'Destroy', classroom_session_path(session), method: :delete, data: { confirm: 'Are you sure?' } %></td>
Related
The following code is implemented to read in values and fill in a table with the appropriate values, however when one of the methods doesn't return anything it produces an error and crashes the page.
<tr class="event-row" >
<td><%= event.description %></td>
<td><%= event.contact.name %></td>
<td><%= event.start.strftime('%H:%M') %></td>
<td><%= event.end.strftime('%H:%M') %></td>
<td><%= link_to "edit", edit_event_path(event) %></td>
<td><%= link_to "delete", event, method: :delete, data: {confirm: "Are you sure?"} %>
<td><%= link_to "show", event_path(event) %></td>
</tr>
How can you check to see if the methods are returning no values?
you can also check if that value is present with if
<tr class="event-row" >
<td><%= event.description %></td>
<td><%= event.contact.name if event.contact %></td>
<td><%= event.start.strftime('%H:%M') if event.start %></td>
<td><%= event.end.strftime('%H:%M') if event.end %></td>
<td><%= link_to "edit", edit_event_path(event) %></td>
<td><%= link_to "delete", event, method: :delete, data: {confirm: "Are you sure?"} %>
<td><%= link_to "show", event_path(event) %></td>
</tr>
You can use try
Try will returns nil rather than raising an exception
event.try(:description)
event.try(:contact).try(:name)
event.try(:start)
event.try(:end)
For more clarification, have a look at this
try public method
You can use try(:name) or delegate with allow_nil:
add this to your event model:
delegate :name, to: :contact, prefix: true, allow_nil: true
and this in your view:
<td><%= event.contact_name %></td>
I have nested resources as below:
resources :categories do
resources :products
end
According to the Rails Guides,
You can also use url_for with a set of objects, and Rails will automatically determine which route you want:
<%= link_to 'Ad details', url_for([#magazine, #ad]) %>
In this case, Rails will see that #magazine is a Magazine and #ad is an Ad and will therefore use the magazine_ad_path helper. In helpers like link_to, you can specify just the object in place of the full url_for call:
<%= link_to 'Ad details', [#magazine, #ad] %>
For other actions, you just need to insert the action name as the first element of the array:
<%= link_to 'Edit Ad', [:edit, #magazine, #ad] %>
In my case, I have the following code which was fully functional:
<% #products.each do |product| %>
<tr>
<td><%= product.name %></td>
<td><%= link_to 'Show', category_product_path(product, category_id: product.category_id) %></td>
<td><%= link_to 'Edit', edit_category_product_path(product, category_id: product.category_id) %></td>
<td><%= link_to 'Destroy', category_product_path(product, category_id: product.category_id), method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
Obviously it is a little too verbose and I wanted to shorten it using the trick mentioned above from rails guides.
But if I changed the Show and Edit link as follows:
<% #products.each do |product| %>
<tr>
<td><%= product.name %></td>
<td><%= link_to 'Show', [product, product.category_id] %></td>
<td><%= link_to 'Edit', [:edit, product, product.category_id] %></td>
<td><%= link_to 'Destroy', category_product_path(product, category_id: product.category_id), method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
Neither of them works any more, and the pages complains the same thing:
NoMethodError in Products#index
Showing /root/Projects/foo/app/views/products/index.html.erb where line #16 raised:
undefined method `persisted?' for 3:Fixnum
What did I miss?
The way Rails is 'automagically' knowing which path to use is by inspecting the objects you pass for their classes, and then looking for a controller whose name matches. So you need to make sure that what you are passing to the link_to helper is the actual model object, and not something like category_id which is just a fixnum and therefore has no associated controller.
<% #products.each do |product| %>
<tr>
<td><%= product.name %></td>
<td><%= link_to 'Show', [product.category, product] %></td>
<td><%= link_to 'Edit', [:edit, product.category, product] %></td>
<td><%= link_to 'Destroy', [product.category, product], method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
I'm guessing the offending line is one of these:
<td><%= link_to 'Show', [product, product.category_id] %></td>
<td><%= link_to 'Edit', [:edit, product, product.category_id] %></td>
The product.category_id is a Fixnum and the routing can't know that a random number is supposed to map to category_id.
Use the previous URLs you had, they're more readable.
I have a two way many-to-many assoication between 3 models: work.rb, category.rb, categorywork.rb
Within the work#index using <%= work.categories %> renders some wonky looking html markup
<% #works.each do |work| %>
<tr>
<td><%= work.name %></td>
<td><%= work.subtitle %></td>
<td><%= work.categories %></td>
<td><%= link_to 'Show', work %></td>
<td><%= link_to 'Edit', edit_work_path(work) %></td>
<td><%= link_to 'Destroy', work, method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
I'm trying to target speific attributes of the association like "name".
Unfortunately when using <%= work.categories.name %> it gets weirder with:
How do i target just the name or just the description?
Try this out:
<%= work.categories.pluck(:name) %>
Hello im learning Rails on my testing app and i have this code
<% #categories.each do |category| %>
<tr>
<td><%= category.name %></td>
<td><%= link_to 'Show', backend_category %></td>
<td><%= link_to 'Edit', edit_backend_categories(category) %></td>
<td><%= link_to 'Destroy', backend_category, method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
and Rake routes shows me this
home_index GET /home/index(.:format) home#index
root / home#index
contact /contact(.:format) home#contact
backend_root /backend(.:format) backend/admin#index
backend_categories GET /backend/categories(.:format) backend/categories#index
POST /backend/categories(.:format) backend/categories#create
new_backend_category GET /backend/categories/new(.:format) backend/categories#new
edit_backend_category GET /backend/categories/:id/edit(.:format) backend/categories#edit
backend_category GET /backend/categories/:id(.:format) backend/categories#show
PUT /backend/categories/:id(.:format) backend/categories#update
DELETE /backend/categories/:id(.:format) backend/categories#destroy
but im getting error that backend_category doesnt exist
here is image
http://www.nahraj-obrazek.cz/?di=213711395092
whats wrong ? Thank you
You must add _path to your link_to helper url, like so
<% #categories.each do |category| %>
<tr>
<td><%= category.name %></td>
<td><%= link_to 'Show', backend_category_path(category) %></td>
<td><%= link_to 'Edit', edit_backend_category_path(category) %></td>
<td><%= link_to 'Destroy', backend_category_path(category), method: :delete, data: { confirm: 'Are you sure?' } %></td>
</tr>
<% end %>
Following Luis answer, any show path needs a reference to an object. So I believe it should be
<td><%= link_to 'Show', backend_category_path category %></td>
Which can also be written as:
<td><%= link_to 'Show', category %></td>
I have this nested recourses
resources :products do
resources :senders
end
In my products/index view I have this
...
..
.
<td><%= link_to 'Show Email Addresses', product_senders_path(product) %> </td>
.
..
...
which seemed to be working and it redirected me to the senders of that product. Now for some strange reason I get this:
NameError in Senders#index
undefined local variable or method `sender_path' for #<#<Class:0x00000003cb1f58>:0x00000003b46e48>
Extracted source (around line #18):
15: <td><%= sender.product_id %></td>
16: <td><%= sender.name %></td>
17: <td><%= sender.email %></td>
18: <td><%= link_to 'Show', sender %></td>
19: <td><%= link_to 'Edit', edit_sender_path(sender) %></td>
20: <td><%= link_to 'Destroy', sender, confirm: 'Are you sure?', method: :delete %></td>
21: </tr>
This is my sender/index file:
<h1>Listing senders</h1>
<table>
<tr>
<th>Application</th>
<th>Name</th>
<th>Email</th>
<th></th>
<th></th>
<th></th>
</tr>
<% #senders.each do |sender| %>
<tr>
<td><%= sender.product_id %></td>
<td><%= sender.name %></td>
<td><%= sender.email %></td>
<td><%= link_to 'Show', sender %></td>
<td><%= link_to 'Edit', edit_sender_path(sender) %></td>
<td><%= link_to 'Destroy', sender, confirm: 'Are you sure?', method: :delete %></td>
</tr>
<% end %>
</table>
<br />
Why I am getting this error? Before it was working fine
As there are only nested routes for senders, there are no edit_sender_path(sender) helper, only edit_product_sender_path(product, sender)
You may see a list of all application route helpers by executing rake routes