ruby on rails render deosn't find the file - ruby-on-rails

I'm new to ruby on rails.
In views/events I have "_form.html.erb" which is rendered in "new.html.erb" by this code:
<%= render "form" %>
Now I want to render "_form.html.erb" in "index.html.erb" which is in the same folder(views/events).
But I get the error "missing template".
I guess I have to add some thing to controller, please help me to render form in other pages of views...

You "usually" don't render a form in an index action. Most form partials are setup semantically to expect a #my_resource, but if you're doing everything the rails way you're not going to have a instance variable during your index action. There's a number of ways you can do this but this is probably the quickest.
You probably have some collection (let's pretend you're using books) in your index action:
#views/books/index.html.erb
<% #books.each do |book| %>
...
<%= render "form" %>
...
<% end %>
You can just set an instance variable somewhere prior to rendering the form:
#views/books/index.html.erb
<% #books.each do |book| %>
<% #book = book %>
...
<%= render "form" %>
...
<% end %>
Another way to do it would be through passing in some locals to a partial. You'd have to change all of your references in _form to use a local variable instead. Then you can call render like this:
<%= render :partial => "form", :locals => {:book => book } %>

You can try
<%= render "events/form" %>
I had this problem before and this solved

Related

Rendering collections within collection in Rails

This is driving me crazy, I thought it should be something very simple but I've spent all day trying to figure it out and getting nowhere. I've looked all over, there's something I must be missing.
I want to render a partial for a collection, within a partial from a collection.
Eg. I have a collection of entries which I want to render in my feed partial, I want feed to come from a collection of feeds, such that the page displays all entries in all feeds.
How can I do this?
Something like:
controller:
#feeds = Feeds.all
allmyfeeds.html.erb
#feeds.each do |feed|
<%= render 'feed' %>
<% end %>
or
<%= render 'feeds', collection: #feeds %>
_feed.html.erb
<%= render 'items', collection: #items %>
_item.html.erb
<%= item.summary.html_safe %>
But I really don't know.
Partial naming conventions will really help you out here...
In allmyfeeds.html.erb (which i'm guessing is actually feeds/index.html.erb), instead of this...
#feeds.each do |feed|
<%= render 'feed' %>
<% end %>
You can simply call this...
<%= render #feeds %> # this will invoke _feed.html.erb for every feed in the collection, automatically
Inside your _feed.html.erb partial...
# Note: You may need to change `items` to something like `items/items` if it is not located in the same directory
<%= render partial: 'items', locals: { items: feed.items } %>
Then in your items partial, you will have access to items, which is a collection of items for that particular feed
Somehting like:
<% #feeds.each do |feed| %>
<%= render partial: 'feed', locals: { feed: feed } %>
<% end %>
In your _feed.html.erb:
<h1><%= feed.id %> </h1>
<% feed.entries.each do |entry| %>
<&= render partial: 'entry', locals: { entry: entry } %>
<% end %>
In your _entry.html.erb:
<h2><%= entry.id %></h2>
I'm assuming your Feed model has a has_many :entries association, if it's not the case (and what you want is to render the same collection of #entries in each feed), then you just need to pass the #entries collection to the _feed.html.slim partial, like:
render partial: 'feed`, locals: { feed: feed, entries: #entries }
and update your _feed.html.erb

undefined method `each' for nil:NilClass while attempting to use a partial

I'm currently having the issue for when I try to use a partial inside of invoices/_form.html.erb, it goes into parts/_index.html.erb and breaks.
Inside of the parts_controller I have:
def _index
#parts = Part.all
end
#unsure if this is needed
Inside of invoices_controller I have:`
def new
#invoice = Invoice.new
#parts = Part.all
end`
Inside of invoices/_form.html.erb I have:
<%= render :partial => "parts/index" , :part => #parts %>
And inside of invoices/new.html.erb I have:
<h1 style="padding-left:120px">New Invoice</h1>
<%= render 'form', invoice: #invoice, part: #parts %>
<%= link_to 'Back', invoices_path, class: "btn btn-default col-md-2" %>
So what this code is attempting to do is display the index page of parts so the user is able to see all current parts they have in stock, and how many of that part is in stock. The parts/index page is the exact same as the the default index page for parts, but it just has a link removed.
The line of code that gives me an issue in parts/index is:
<% #parts.each do |part| %>
And what's confusing me about that is that I should be passing it an object that has data inside of it, since it's declared in both the controller for parts, and the invoice controller. Am I missing something super simple with my syntax, or is what I'm trying to do not the right way to do it? I'm still a noob to rails, so sorry if what I'm trying to get across doesn't make too much sense.
so here is the problem:
<%= render :partial => "parts/index" , :part => #parts %>
you are sending :part to your _index.html.erb partial while using #parts
you need to update your render call to following:
<%= render :partial => "parts/index" , locals: {parts: #parts}%>
and your loop to:
<% parts.each do |part| %>
you provide to _index.html.erb variable part but try to render #parts.
1. you don't need method _index, when your patial _index.html.erb render that not get variable #parts from method _index. I think it's wrong.
2. You need to render in _index.html.erb variable which it's provided from _form
<% part.each do |part_| %>

Ruby on Rails: Passing a variable to a partial that can be of different classes

Note: Apologies if this is a duplicate, I couldn't find an answer. Warning: Newbie to RoR, the answer is probably incredibly obvious.
I have a partial, _show_address_on_map, which shows the location of a person on a map. However, this person can be an #employee or a #client, and can be called from the employee_addresses controller or the client_addresses controller. Depending on which of the two it is, some things need to be changed within the partial.
In employee_addresses/show.html.erb I call the partial with
<%= render :partial => ".../show_on_map", currentUser: #employee %>
In client_addresses/show.html.erb I call the partial with
<%= render :partial => ".../show_on_map", currentUser: #client %>
Now in the partial (_show_address_on_map) I try to do an if-statement on currentUser:
<% if currentUser.is_a?(Client) %>
#do something with #client
<% else %>
#do something with #employee
<% end %>
This gives me the error "undefined local variable or method 'currentUser'"
How do I correctly define currentUser, so that it can be either #employee or #client as described? Or am I doing something else wrong?
<%= render :partial => ".../show_on_map", locals: {current_user: #client}%>
:)
Also as a ruby/rails convention, use the under_score rather than camelCase
You can use the :object to send a data into the partial, and that will define a variable with the same name as the partial
<%= render :partial => ".../show_on_map", :object => #client %>
So in your partial, you can reference the :object send with the name of the partial _show_address_on_map, you can do something like this:
<% if show_address_on_map.is_a?(Client) %>
#do something with #client
<% else %>
#do something with #employee
<% end %>
And that will contain the #client sent in :object, so you can control what action do in the partial.

Rails Partials For Resources

I have a resource called Exercises in my application. I currently have a partial called _exercise.html.erb that I use to render them. I have an outlying case where I'd like to render them in a much different way. Can I make another partial for exercises that has this other format and still be able to use <%= render #exercises %>?
If not what is the best approach? Should I out a variable in the controller that tells the partial which layout to use, this would have both layout in one file and one if to decide. Or is there some better way?
If you'd like to use business logic to determine when to show what partial for your #exercises collection you should use the to_partial_path method in the Exercise model to define that. See #4 in this post: http://blog.plataformatec.com.br/2012/01/my-five-favorite-hidden-features-in-rails-3-2/
Or, if this is more of a view-related decision (i.e. one view will always use the regular _exercises.html.erb and another view would always use e.g. _alternate_exercises.html.erb) then you can specify as such:
<%= render partial: 'alternate_exercises', collection: #exercises, as: :exercise %>
This will render the _alternate_exercises.html.erb partial once for each item in #execrises passing the item in to the partial via a local_assign called exercise.
In this case, I suppose you have two options:
1) Put the conditional code inside of _exercises.html.erb
eg.
<% if #exercise.meets_some_condition %>
you see this stuff
<% else %>
you see other stuff
<% end %>
This way, you can still make use of <%= render #exercises %>
2) Otherwise, your other option is to have separate partials and render them outside.
eg.
<% #exercises.each do |exercise| %>
<% if exercise.meets_some_condition %>
<%= render "exercises/some_condition_exercise" %>
<% else %>
<%= render "exercises/exercise" %>
<% end %>
<% end %>
This is the best approach for rendering partial. You can wrap that partial with if else statement in your code. Here is my example
rendering with form called _victim.html.erb
<%= render :partial => "victim", :locals => {:f => f }%>
rendering without form
<%= render :partial => "victim"%>

ruby-on-rails: rendering partials on each item in a list

I have the following in a view (.html.erb) :
<% #posts = GetAllPostsFunctions %> (removed for berivity)
<% #posts.each do |post| %>
<%= post.title %>
<%= render :partial => "posts/post_show" %>
<% end %>
the posts_show partial has the following:
....
<td><%=h #post.title %> </td>
But I get the following error
You have a nil object when you didn't expect it!
The error occurred while evaluating nil.title
Any ideas?
You can also simply things by using the :collection for render :partial. Which pass each item in the value for :collection to a local variable sharing the name of your partial.
<% #posts = GetAllPostsFunctions %> (removed for berivity)
<%= render :partial => "posts/post_show", :collection => #posts %>
In this case, Rails will render post_show for each item in #posts with the local variable post_show set to the current item. It also provides handy counter methods.
Successfully using this approach would require renaming the app/views/posts/_post_show.html.erb partial to app/views/posts/_post.html.erb to or changing every occurance of post in your partial to post_show. If you renamed the partial to the conventional _post.html.erb which will then allow you to simply do:
<%= render :partial => #posts %>
Which will render the partial for every single post in the #posts variable.
Since the post variable in the each loop is a locale variable you have to make it available to the partial:
<%= render :partial => "posts/post_show", :locals => {:post => post} %>
You can then access the title through the local variable post:
<td><%=h post.title %> </td>
You could also simplify the whole thing by rendering the posts as collection. Take a look at the Rails documentation for more information:
http://api.rubyonrails.org/classes/ActionController/Base.html#M000658
It doesn't look like you're setting the #post of the partial, so when it goes to evaluate the partial it gets a null reference.
Alternately, ensure that your post fetching functions are actually returning something
I'm not positive, but I think in the partial you have to do post.title not #post.title
Sorry if I misunderstood you, I'm new to rails.

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