Using mail_to with a block (mail_to ... do) - ruby-on-rails

I would like to do the following to insert a styled mail_to:
<%= mail_to #colleague.email do %>
<span class="email" id="colleague_40"> Reply by Email </span>
<% end %>
The RoR docs aren't specific on the topic of mail_to blocks but the above code doesn't seem to work. Is there a way to do a block in conjunction with mail_to?

<% mail_content = capture do %>
<span class="email" id="colleague_40"> Reply by Email </span>
<% end %>
<%= mail_to #colleague.email, mail_content %>

Related

Poor Performance in Rails App

Looking for ways to improve the particularly bad performance I'm getting from my rails application. Here's the code from the page in question:
notifications_controller.rb
class NotificationsController < ApplicationController
def index
#questions = Question.all.order(:updated_at => :desc)
#users = User.all
#answers = Answer.all.order(:updated_at => :desc)
end
end
and here's the corresponding view. I know it's ugly but it's working.
<div>
<% if current_user %>
<div class="notifications-added col-md-8">
<h4 class="col-md-offset-2">Approvals & Answers</h4>
<span class="text-center">
<% current_user.questions.order(id: :desc).each do |question| %>
<% if question.approved == true %>
Your question, <%= link_to "#{question.title}", question_path(question) %>, has been <span class="notifications">approved.</span><br>
<% end %>
<% question.answers.each do |answer| %>
<%= answer.user.name %> <span class="notifications">added an answer</span> to your question, <%= link_to "#{question.title}", question_path(question) %>.<br>
<% end %>
<% end %>
</span>
</div>
<div class="notifications-voted col-md-4">
<h4 class="text-center">Votes</h4><span></span>
<% current_user.answers.order(updated_at: :desc).each do |answer| %>
<% #users.each do |user| %>
<% if user.voted_up_on? answer %>
<%= user.name %> <span class="notifications">upvoted</span> your answer to <%= link_to "#{Question.find(answer.question_id).title}", question_path(answer.question_id) %>.<br>
<% elsif user.voted_down_on? answer %>
<%= user.name %> <span class="notifications">downvoted</span> your answer to <%= link_to "#{Question.find(answer.question_id).title}", question_path(answer.question_id) %>. <br>
<% end %>
<% end %>
<% end %>
</div>
<% end %>
</div>
I think I'm just sorting too much. The page is taking a long time to load. What's the low hanging fruit for improving my performance? Any thoughts? Thanks in advance.
The first , you should move logic code in your view into model.
The second , use pluck method instead array active record objects. Array string are lightweight than array of active record. Right ?
The third , use slim template engine instead erb template engine.
The fourth , cache db.
The fiveth, use google PageSpeed plugin for google chrome to analytic what's slow.
Peter answer is correct, and I will add two things :
Eager loading
Doing this
current_user.questions.each do |question|
question.answers.each do |answer|
...
end
end
will generate a query for each question. Rails will load all the questions, then for each question load its associated answers (1 query + 1 query for any question).
If you replace the first line by
current_user.questions.include(:answer).each do |question|
Rails will load all the questions, then all the associated answers (2 queries).
Look at the log
Every information for any bad performance should be visible on logs in development mode. For example, if voted_up need to load any other models than answer, your query number will be too big.

Ruby on Rails how to get last query?

I'm having trouble trying to figure out when I reached the end of my query. So what I want to do is list all the records in my database that begin with the letter A which I got however I want to output a message if the query turns out blank. When I try I get a bunch of my custom messages even the query didn't turn out blank. Is there any way to tell if I've reached EOF in ruby on rails?
Sample
<div id = "content-A">
<p>A</p>
<% #animes.each do |anime| %>
<% if anime.aname.starts_with?('A') %>
<%= link_to anime.aname, {:action => 'list'} %>
<% else %>
<p>No anime listed in this Category :( </p>
<%end%>
<%end %>
</div>
I believe you want sth like:
<% animes_group = #animes.group_by {|anime| anime.aname.to_s[0].upcase}
('A'..'Z').each do |letter| %>
<div id="content-<%= letter %>">
<p><%= letter %></p>
<% if animes = animes_group[letter] %>
<% animes.each do |anime| %>
<%= link_to anime.aname, {:action => 'list'} %>
<% end %>
<% else %>
<p>No anime listed in this Category :( </p>
<%end%>
<% end %>
You should consider moving some of the logic to the controller here, however what is to be moved depends on many factors like whether #animes are being used anywhere else etc.

Rails: DRYing similar but different views

I have a pair of very similar views that render almost identical information, only in one view there are couple of extra columns and in the other the rows link slightly different nested resources. My initial approach was to keep it DRY by using a partial and then placing conditionals throughout the view. The resulting partial looked something like this:
<div id='overview_table'>
<div id="overview_header">
<span id="sort_title" class="title cell">Title<span id="publication_sort_arrow"> ↓</span></span>
<span id="sort_author" class="author cell">Author</span>
<span id="sort_status" class="status cell">Status</span>
<% if #user.present? %>
<span id="sort_impression_date" class="date cell">Date</span>
<span id="sort_impression_vote" class="votes cell">Votes</span>
<span id="sort_children_total" class="children_total cell">Replies</span>
<% end %>
</div>
<span id="sort_method">title ASC</span>
<% #publications.each do |publication| %>
<div class='<%= cycle("odd", "even") %>'>
<% if #user.present? %>
<% link = [#user, publication] %>
<% else %>
<% link = [#group, publication] %>
<% end %>
<%= link_to(link, :remote => true) do %>
<span class="title cell"><%= publication.full_title %></span>
<span class="author cell"><%= publication.authors %></span>
<span class="status cell"><%= publication_status(publication.status) %></span>
<% if #user.present? %>
<span class="date cell"><% if publication.impression_date %><%= publication.impression_date.strftime("%B %d, %Y") %><% end %></span>
<span class="votes cell"><% if publication.impression_vote %><%= publication.impression_vote.to_i %><% end %></span>
<span class="children_total cell"><% if publication.impression_vote %><%= publication.children_total %><% end %></span>
<% end %>
<% end %>
</div>
<% end %>
It worked fine, but the code felt hacky. I ultimately separated these back out into the two different views, though now there's a lot of repeated code. Both approaches feel inadequate. Is there another approach that I'm not considering?
There are different strategies here but in this case if you are just adding some fields, I would do something like this (which is similar to what you are doing).
in my controller I'll set some tag value to true:
#show_val_extra=true
and in my view(probably be a partial so rather than inline code in your example):
<%="something here" unless #show_val_extra.nil? %>
No matter what you are going to have to check and other issues of managing the view in the controller are ugly to me. YMMV but this is what I'd do since it basically makes it to a single value and a single check for when you want different information. Usually, it's in multiple places but you have content in multiple places and a further refactor is easy if the situation arises.

Can one use conditions and loops on a single line in Ruby?

How would one go about turning the following code into the latter?
<div id="faqs">
<% if #faqs.length > 0 %>
<% #faqs.each do |faq| %>
<div class="faq">
<strong>Q:</strong> <%= faq.question %>
<br />
<strong>A:</strong> <%= faq.answer %>
</div>
<% end %>
<% else %>
<p>No FAQs to display.</p>
<% end %>
</div>
<div id="faqs">
<% #faqs.empty? ? content_tag(:p, "No FAQs to display.") : #faqs.each do |faq| %>
<div class="faq">
<strong>Q:</strong> <%= faq.question %>
<br />
<strong>A:</strong> <%= faq.answer %>
</div>
<% end %>
</div>
I'm curious as to whether I can get the latter code to work. The only element of it that is failing at the moment is that the content_tag() is not displaying - this is due to the fact that I'm not using printable ruby tags (<%= # %>) but using them will dump out the FAQ objects underneath the content.
I considered the use of puts() to print the content_tag() while inside the ruby tags but that didn't work.
I've tried to search for this issue but haven't yielded anything useful.
Is this achievable and if so, does it have any benefits other than being prettier?
One way to make the later code to work if you can put the body of the loop in a helper function and return the out put of content_tag from that. The line in view file might be somewhat like this.
<%= #faqs.empty? ? content_tag(:p, "No FAQs to display.") : printList(#faqs) %>
and your printList function will return the output of nested content_tags. You can make a generic list printing function which can be used for any list.
Something so obvious but still shared.
This should work (for clarity, I moved FAQ tag generation in separate helper method):
<div id="faqs">
<%= raw (#faqs.empty? ? content_tag(:p, "No FAQs to display.") : #faqs.map { |faq| faq_div(faq) }.join) %>
</div>
or, perhaps more clean:
<div id="faqs">
<%= content_tag(:p, "No FAQs to display.") if #faqs.empty? %>
<%= raw #faqs.map { |faq| faq_div(faq) }.join %>
</div>
meanwhile, in helpers:
def faq_div(faq)
'<div class="faq"><strong>Q:</strong> %s<br /><strong>A:</strong> %s</div>' % [faq.question, faq.answer]
end
This should work:
<% if #faqs.each do |faq| %>
<div class="faq">
<strong>Q:</strong> <%= faq.question %>
<br />
<strong>A:</strong> <%= faq.answer %>
</div>
<% end.empty? %>
<p>No FAQs to display.</p>
<% end %>

How do I wrap link_to around some html ruby code?

How do I wrap a link around view code? I can't figure out how to pass multiple lines with ruby code to a single link_to method. The result I am looking for is that you click the column and get the show page:
<div class="subcolumns">
<div class="c25l">
<div class="subcl">
<%= image_tag album.photo.media.url(:thumb), :class => "image" rescue nil %>
</div>
</div>
<div class="c75r">
<div class="subcr">
<p><%= album.created_at %></p>
<%= link_to h(album.title), album %>
<p><%= album.created_at %></p>
<p><%= album.photo_count %></p>
</div>
</div>
</div>
link_to takes a block of code ( >= Rails 2.2) which it will use as the body of the tag.
So, you do
<%= link_to(#album) do %>
html-code-here
<% end %>
But I'm quite sure that to nest a div inside a a tag is not valid HTML.
EDIT: Added = character per Amin Ariana's comment below.
Also, this may be an issue for some:
Make sure to write <%= if you are doing a simple link with code in it instead of <%.
e.g.
<%= link_to 'some_controller_name/some_get_request' do %>
Hello World
<% end %>
For older Rails versions, you can use
<% content_tag(:a, :href => foo_path) do %>
<span>Foo</span>
<% end %>
You can use link_to with a block:
<% link_to(#album) do %>
<!-- insert html etc here -->
<% end %>
A bit of a lag on this reply I know -- but I was directed here today, and didn't find a good answer. The following should work:
<% link_to raw(html here), #album %>

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