I have a main page that is responsible for HTML/CSS styling, but some of the contents come from partials. A partial receives some locals or params, i.e. current_user or person, and displays information if any.
Is there a way for me to check if a partial rendered anything? My end goal is something like this:
<% if my_partial can render something %>
<div class="css_for_something">
<%= render(partial: 'my_partial', locals: {...} ) %>
<% else %>
<div class="css_for_no_info">
<%= render something else %>
<% end %>
I do not want the partials to handle styling logic; they just need to display content if any. Conversely, the main page should not know anything about the logic in the partial(s), such as checking values or querying the database.
Thank you
Unfortunately, Chris Peter's solution did not work for me on rails 4.2.4, as render_to_string seems to not be available in views.
However, the following worked (rails 4.2.4):
<% partial_content = render partial: 'my_partial' %>
<% if partial_content.present? %>
<%= partial_content %>
<% else %>
<%# rendered if partial is empty %>
<% end %>
Be aware that the present? check really only checks if what was rendered is empty. If, something, e.g. a HTML comment, is returned, the check returns false.
Try storing the value generated by render_to_string in a variable:
<% partial_content = render_to_string(partial: 'my_partial', locals: {...} ).strip %>
Then you can see if it contains any content:
<% if partial_content.present? %>
<%= partial_content %>
<% else %>
<div class="css_for_no_info">
<%= render something else %>
</div>
<% end %>
Related
I am building webstore. I added a bit of AJAX functionality to add, update and remove items from my cart without refreshing.
It works perfect as long as there are no items in a cart and render cart_empty partial properly.
The problem is when I add few items, and I can update/remove them without refreshing and
finally I remove the last one, and it do not switch to the cart_empty partial and there are only empty table headers left from cart-items partial.
Can I add some logic to destroy.js.erb?
destroy.js.erb
$("#cart-item").html("<%= j render 'carts/cart_items' %>");
the show.html.erb contains this unless function:
<% unless current_order.order_items.empty? %>
<div id="cart-item">
<%= render 'cart_items' %>
</div>
<% else %>
<div id="cart-empty">
<%= render 'cart_empty' %>
</div>
<% end %>
Maybe should I modify somehow my controller to check if there are order_items in a current_order?
Thank you!
A JS.erb template is evaluated in exactly the same way as a HTML template. So you can just add a condition:
<% if current_order.order_items.any? %>
$("#cart-item").html("<%= j render 'carts/cart_items' %>");
<% else %>
$("#cart-item").html("<%= j render 'carts/cart_empty' %>");
<% end %>
None that this implies that current_order is either a helper or a local passes to the view.
But you might want to refactor this and push the condition down to the partial:
# carts/cart_items.html.erb
<% if cart_items.none? %>
<% render :cart_empty %>
<% else %>
# ...
<% end %>
Which will let you just write:
<%= render 'carts/cart_items', cart_items: current_order.order_items %>
See:
Layouts and Rendering in Rails - passing local variables
So I'm passing down locals to a partial via PublicActivity and try to render the partial on the users/show.html.erb file, like so:
<% #activities.each do |act| %>
<% render partial: "posts/#{act.trackable.check_type}",
locals: { tweet: tweet.trackable }%>
<% end %>
But this results into nothing. I don't see the partial at all. It's not visible. All data that is passed down is not nil, double confirmed via byebug and rails console.
Any ideas what could cause the invisibility of the partial?
<% %> Executes the ruby code, but doesn't print it.
<%= %> Prints the result into the erb file.
So, the code should be:
<%= render partial: "posts/#{act.trackable.check_type}",
locals: { tweet: tweet.trackable }%>
More:
<%# %> : is for comment in erb
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." %>
I have a very simple requirement - I have a layout comprising of a header and body. It is a sub-layout of the page, not for the page itself.
This layout is repeated throughout multiple pages, and it is possible the structure around it will change. So I want to be able to separate the content of the header and the content of the body from the structure that contains it.
My first attempt was to use render a partial as a layout that used named yields to render a header and body:
<header class="Resource-header">
<%= yield :resource_header %>
</header>
<div class="Resource-body">
<%= yield :resource_body %>
</div>
Then render it from my templates like this:
<%= render layout: 'admin/resource' do %>
<% content_for :resource_header do %>
<% end %>
<% content_for :resource_body do %>
<% end %>
<% end %>
However, this renders nothing.
I started playing with the order of things, and discovered that if the content_for blocks are declared before the call to the partial, this approach does work:
<% content_for :resource_header do %>
<% end %>
<% content_for :resource_body do %>
<% end %>
<%= render layout: 'admin/resource' do %><% end %>
However this just feels incredibly hacky. It seems that content_for is scoped globally, and there is no association between the content_for block and the partial rendering.
So what is the correct way for me to achieve this?
I just happened to have exactly same problem.
Solution is:
in your partial layout file 'admin/resource' body:
<header class="Resource-header">
<%= yield resource, :resource_header %>
</header>
<div class="Resource-body">
<%= yield resource, :resource_body %>
</div>
in your templates do:
<%= render layout: 'admin/resource' do |resource, section| %>
<% case section %>
<% when :resource_header %>
Resource header shows here.
<% when :resource_body %>
Resource body shows here.
<% end %>
<% end %>
Take a look on rails presenters https://www.ruby-toolbox.com/categories/rails_presenters
Maybe your solution is cells gem.
Eventhough the question is quite old now, I had a similar issue today. I came up with sth. like this. No gem or custom class required, just some fancy block usage ;)
<!-- app/views/layouts/fancy-blocks.html.erb -->
<%
body, footer = nil
yield(
proc {|&blk| body = capture(&blk) },
proc {|&blk| footer = capture(&blk) }
)
%>
<section class="body"><%= body %></section>
<footer><%= footer %></footer>
<!-- app/views/some-other/view.html.erb -->
<%= render 'layout/fancy-blocks' do |body, footer| %>
<% body.call do %>
BODY
<% end %>
<% footer.call do %>
FOOTER
<% end %>
<% end %>
I have a table in a partial _measures_findings_list.html.erb where I want to replace the table row with another partial, which I can reuse elsewhere. MeasuresFinding is a model, so I first created a partial _measures_finding.html.erb, and tried:
<% render #measures_findings %>
then I tried
<% #measures_findings.each do |measures_finding| %>
<% render 'measures_finding', measures_finding: measures_finding %>
<% end %>
Nothing. Then
<% #measures_findings.each do |measures_finding| %>
<% render 'measures_finding/measures_finding', measures_finding: measures_finding %>
<% end %>
What am I doing wrong? Putting the code of the partial into the each loop works of course.
You miss '=', it should be
<%= render #measures_findings %>