I have a rails app with some views and I'd like to display something different if the view is the array doesn't contain any data. At the moment my view looks like this:
<% #trips.each do |trip| %>
<p><%= trip.id %> | <%= trip.name %></p>
<% end %>
But is there a way I can show some different text if this doesn't have anything inside #trips ?
If you use partials:
trips/_trip.html
<p><%= trip.id %> | <%= trip.name %></p>
your view
<%= render #trips || 'No trip' %>
You can use an if/else conditional check:
<% if (#trips != nil) then %>
<p><%= trip.id %> | <%= trip.name %></p>
<% else %>
<p>Some message</p>
<% end %>
or
<% if (#trips.blank?) then %>
<p>Some message</p>
<% else %>
<p><%= trip.id %> | <%= trip.name %></p>
<% end %>
sure, just use an if there, like this
<% if #trips.blank? %>
<p>No trips</p>
<% else %>
<% #trips.each do |trip| %>
<p><%= trip.id %> | <%= trip.name %></p>
<% end %>
<% end %>
Use a if statement and check if it is null or empty like this
<% if #trips.nil? || #trips.empty? %>
<p>There are no trips</p>
<% else %>
<% #trips.each do |trip| %>
<p><%= trip.id %> | <%= trip.name %></p>
<% end %>
<% end %>
Edit
If working withing rails you would probably want to go with #trips.blank?, if you decide on another ruby framework or project then you can use the above if/else code to check if a array is null or empty
Related
I am working on a RAILS application where I create a view which lists all available resources of a given model species.rb.
The view partial is:
<% i= #s
for species in #species %>
<%= species.name %>, <%= species.author.surname %> <%= species.author.initial_name %>
<% i -= 1
end %>
Some of the resources species have an related article, others have only the name. I would like to loop through the partial and add a link only to the entries which have an associated article.
Something like: add link if species.article is present else just put species.name without link + loop through it for all entries.
How can I do this?
UPDATE:
Thanks to #jvillian and #fool-dev I was able to progress. In my case I wanted to add a link if the resource has a description in a description row of its table.
<% #species.each do |species| %>
<div class="entry">
<p><i><%= link_to_if(species.txtlandscape.present?, "#{species.name}, #{species.author.surname}, #{species.author.initial_name}. 2014", :controller => 'projects', :action => 'show', :id => species) %></i></p>
</div>
<% end %>
Now that a link is added I was wondering if it can be used to load a partial to a target such as in, where ArticleRequest is a JS function I have:
<% # species.each do | species | %>
<div id="species-<%= species.id %>" class="species-entry">
<a onClick="ArticleRequest('/species/show/<%= species.id %>', 'species-<%= species.id %>');">
<p><%= species.name %></p>
</a>
</div>
<% end %>
Until I find a way to do this with link_to_if, I will use something like:
<% for species in #species %>
<% if species.txtlandscape.present? %>
<a onClick="ArticleRequest('/species/show/<%= species.id %>', 'species-<%= species.id %>');">
<p><%= species.name %>, <%= species.author.surname %> <%= species.author.initial_name %></p>
</a>
<% else %>
<p><%= species.name %>, <%= species.author.surname %> <%= species.author.initial_name %></p>
<% end %>
<% end %>
According to the docs, it seems you should be able to do:
<% #species.each do |specie| %>
<%= link_to_if(specie.article, specie.name, specie_article_path(specie.article)) %>
<% end %>
I made the path name up, you'll have to make that match your actual routes.
BTW, this:
for species in #species
Is super non-idiomatic.
You can do this, see the below
<% for species in #species %>
<% if species.article.present? %> #=> I thin it will be articles because table name is articles, anyway, you know better
<%= link_to species.name, link_path(species.article) %>, #=> on the link_path it will be your proper link just replace this
<% else %>
<%= species.name %>,
<% end %>
<%= species.author.surname %> <%= species.author.initial_name %>
<% end %>
You can do this with Rails each method like below
<% #species.each do |species| %>
<% if species.article.present? %> #=> I thin it will be articles because table name is articles, anyway, you know better
<%= link_to species.name, link_path(species.article) %>, #=> on the link_path it will be your proper link just replace this
<% else %>
<%= species.name %>,
<% end %>
<%= species.author.surname %> <%= species.author.initial_name %>
<% end %>
Or you can use link_to_if it is also most easier to understand
<% #species.each do |species| %>
<%= link_to_if(species.article.present?, "#{species.name},", link_path(species.article)) %>
<%= species.author.surname %> <%= species.author.initial_name %>
<% end %>
Hope it will help.
I'm new to rails. I have this block in my view afrikaans.html.erb
<% #afrikaans.each do |course| %>
<div class="course">
<h3 class="course-name"><%= link_to course.name, course.url %></h3>
<% if I18n.locale == I18n.default_locale %>
<p class="course-description_en"><%= course.description_en %></p>
<% else %>
<p class="course-description_se"><%= course.description_se %></p>
<% end %>
<% if course.youtube_url.blank? == false %>
<p><%= raw ApplicationHelper.youtube_embed(course.youtube_url) %></p>
<% end %>
<% if course.language_id == 1 %>
<p> <%= image_tag("eng.png", :alt => "England", :class =>"round") %></p>
<% else %>
<p> <%= image_tag("swe.png", :alt => "Sweden", :class =>"round") %></p>
<% end %>
<% if ApplicationHelper.active_link?(course.url) == false %>
<td><%= I18n.t('home.broken_link') %></td>
<% end %>
<p><%= course.nbr_of_votes %> <%= I18n.t('home.votes') %></p>
</tr>
<% end %>
I also have another file swahili.html.erb with the same structure. I wanted to implement something like this
afrikaans.html.erb
<% #afrikaans.each do |course| %>
<%= render 'shared/partial' %>
<% end %>
So that I can also have
swahili.html.erb
<% #swahili.each do |course| %>
<%= render 'shared/partial' %>
<% end %>
The partial will contain the part of the block. I've tried this but it's not working. My question is this even possible in rails and if so what could be the problem. What options do I have if it isn't possible so that I can avoid the repetition since the two files have the same structure?
Update. This One worked out for me. I only needed to add :course => course on the block so that my views becomes something like
<% #afrikaans.each do |course| %>
<%= render 'shared/course_body', :course => course %>
<% end %>
Of course I've not named my partial "partial". This was just a matter of asking. Thanks to one #Alexander Panasyuk's answer.
Just create shared directory within your app/views path. And create file _partial.html.erb inside shared:
<div class="course">
<h3 class="course-name"><%= link_to course.name, course.url %></h3>
<% if I18n.locale == I18n.default_locale %>
<p class="course-description_en"><%= course.description_en %></p>
<% else %>
<p class="course-description_se"><%= course.description_se %></p>
<% end %>
<% if course.youtube_url.blank? == false %>
<p><%= raw ApplicationHelper.youtube_embed(course.youtube_url) %></p>
<% end %>
<% if course.language_id == 1 %>
<p> <%= image_tag("eng.png", :alt => "England", :class =>"round") %></p>
<% else %>
<p> <%= image_tag("swe.png", :alt => "Sweden", :class =>"round") %></p>
<% end %>
<% if ApplicationHelper.active_link?(course.url) == false %>
<td><%= I18n.t('home.broken_link') %></td>
<% end %>
<p><%= course.nbr_of_votes %> <%= I18n.t('home.votes') %></p>
</tr>
Then render your partial in afrikaans.html.erb like that:
<% #afrikaans.each do |course| %>
<%= render 'shared/partial', :course => course %>
<% end %>
or in swahili.html.erb:
<% #swahili.each do |course| %>
<%= render 'shared/partial', :course => course %>
<% end %>
It is most definitely possible, and usually a good idea.
In the future it would be nice if you could post the actual results and/or error messages you get, which would help a lot when trying to help you.
That said, I'm guessing you need to pass the course variable to your partial. Change
<%= render 'shared/partial' %>
to
<%= render 'shared/partial', :course => course %>
Partials do not have access to local variables in other partials. In that sense you can think of each partial as separate methods on the same object instance.
<%= render 'shared/partial', locale: 'swahili', course: course %>
You will have local vars 'locale' and 'course' in your partial set to 'swahili' and #course, respectively. Also, I'd advise to name your partials something more meaningful, like 'course'.
Hi i need to print out just the candidates where active is == 0 here is my code in the view.
I can print if active is yes or no.. But in the each do loop i just want to print the active candidates.
So how can i add the condition to my each do loop, thanks.
<% #candidates.each do |candidate| %>
<div id="candidateper">
<div class="avatth" ><div class="avat_min">
<% if candidate.avatar.present? %>
<%= link_to (image_tag candidate.avatar.url(:thumb)), (candidate_path(candidate)) %>
<% else %>
<%= link_to (image_tag ("espanol/playersample.png")), (candidate_path(candidate)) %>
<% end %>
</div></div>
<div class="nameth"><%= candidate.name %></div>
<div class="activeth"><%= candidate.active ? t('generales.yess') : t('generales.noo') %></div>
<div class="generalth">
<% if candidate.user.purchased_at.present? %>
<%= candidate.user.purchase_defeated? ? t('generales.defeated') : t('generales.active') %>
<% else %>
<%= t('generales.noo') %>
<% end %>
</div>
<div class="actionsth"><%= link_to t('generales.show'), candidate_path(candidate) %>
<% if current_user.user_type == 'admin' %>
<%= link_to t('generales.delete'), candidate_path(candidate), method: :delete, data: { confirm: t('generales.delete_candidate_confirm') } %>
<% end %>
</div>
</div>
<% end %>
</div>
<% end %>
I`ve tried this
no luck syntax error on all my ideas :P
If candidate.active is actually a boolean then you could say:
<% #candidates.reject(&:active).each do |candidate| %>
...
<% end %>
If #candidates is actually an ActiveRecord::Relation then you could probably say:
<% #candidates.where(:active => false).each do |candidate| %>
...
<% end %>
to avoid pulling a bunch of stuff out of the database when you don't want it.
If active is actually a number (inside the database and outside the database) then you could say:
<% #candidates.select(&:zero?).each do |candidate| %>
...
<% end %>
or
<% #candidates.where(:active => 0).each do |candidate| %>
...
<% end %>
I need to apply a regular expression in html.erb
<% taxon_name.strains.each do |strain| %>
<% taxon_name.strain_appendices.each_with_index do |strain_appendice, i| %>
<% if ((strain_appendice.data_source =~ /LPSN/) && (strain.relevance =~ /^ty(.*)ain$/))%>
<% if i == 0 %>
<p><%= strain_appendice.appendix %> </p> <% strain.strain_id %> <% strain.relevance %>
<%else%>
<%= strain_appendice.appendix %> - <% strain.strain_id %> <% strain.relevance %>
<%end%>
<%end%>
This code replaces the all content of a strain.strain_id & strain.relevance and doesnot passes match criteria. Instead of matching it replacing strain.strain_id & strain.relevance contents.
Kindly tell me the way to match and pass conditions.
--
With Regards,
Palani Kannan. K,
This code is working for me if I add two <%end%> statements at the end, like this:
<% taxon_name.strains.each do |strain| %>
<% taxon_name.strain_appendices.each_with_index do |strain_appendice, i| %>
<% if ((strain_appendice.data_source =~ /LPSN/) && (strain.relevance =~ /^ty(.*)ain$/))%>
<% if i == 0 %>
<p><%= strain_appendice.appendix %> </p> <%= strain.strain_id %> <%= strain.relevance %>
<%else%>
<%= strain_appendice.appendix %> - <%= strain.strain_id %> <%= strain.relevance %>
<% end %>
<% end %>
<%end%>
<%end%>
Dear All,
When I use a table from database, if data is not available in table. I will use if and else conditions like
<% if #tables.blank? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
It works fine. Now I need to apply the same thing for connected tables. If data is available in first table tables and not available in benches. How I can apply??
I tried like this
<% #tables.each do |table| %>
<% if table.benches.blank? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
<% end %>
... But its not working. Kindly give me suggestions.
I'm not quite sure what you want, but maybe this will help you.
<% if #tables.blank? %>
<p> Not available</p>
<% else %>
<% #tables.each do |table| %>
<% if table.benches.blank? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
<% end %>
<% end %>
Try using #empty?.
<% #tables.each do |table| %>
<% if table.benches.empty? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
<% end %>
What happens if you try this:
<% unless table.benches.exists? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
if/else must output one or the other... make sure you check your HTML source code (not just browser view) to see if the output isn't hiding somewhere inside a tag.
Dear All, Its working... when i apply like this...
<% if #tables.blank? %>
<p> Not available</p>
<% else %>
<% #tables.each do |table| %>
<% table.benches.each do |bench| %>
<% if bench.column.blank? %>
<p> Not available</p>
<% else %>
blaaa blaa
<% end %>
<% end %>
<% end %>
<% end %>
Thank you for everyone who participated in this Question.