In reference to this
I've created a question in a webform like this:
<div class="form_row">
<label for="features[]">Features:</label>
<% [ 'scenarios', 'role_profiles', 'private_messages', 'polls' ].each do |feature| %>
<br><%= check_box_tag 'features[]', feature,
(params[:features] || {}).include?(feature) %>
<% end %>
</div>
So if scenarios and private_messages gets checked and I print out params[:features] I will get:
scenariosprivate_messages
I was wondering how would I be able to obtain scenarios and private_messages separately from params. Is the mapping params[:features] = "scenariosprivate_messages" or is it really params[features] = ["scenarios", "private_messages"] ? If it's the latter how can I loop through them?
I write in my view:
<%= params[:features].each {|param|
param.capitalize
} %>
and I still just get scenariosprivate_messages printed.
Try this instead:
<% params[:features].each do |param| %>
<%= param.capitalize %>
<% end %>
The problem with your original solution is that you're printing out the result of the block, which is the array itself, rather than printing out each element of the array.
You shouldn't be using params in your views. You're best off assigning params[:features] to an instance variable in your controller and then iterating over that in your view.
But to answer your question, you're putting the equals sign for output in the wrong place. You want to output each element of the array individually instead of outputting the result of the loop.
You must use humanize:
<% params[:features].each do |param| %>
<%= param.humanize %>
<% end %>
According to this blog post you should be able to access them individually as params[:features]['scenarios'] etc. Looping should just work like with all other arrays -- eg
params[:features].each { |param|
# do something with param
}
Related
I'm in the process of refactoring some code. I'm trying to use arrays in my view as part of a for loop that makes columns in a table.
I have defined the arrays in my controller:
subjects_controller.rb
def index
...
#CRFS_TO_VIEW = [Baseline, TreatmentCompletion]
#CRF_PATH = {Baseline => 'baseline_path', TreatmentCompletion => tc_path}
end
So my goal; as the function iterates over #CRFS_TO_VIEW, the correct path is selected from #CRF_PATH and appended to the link_to function.
indext.html.erb
<% #CRFS_TO_VIEW.each do |crf| %>
<% path = #CRF_PATH[crf] %>
<%= link_to "edit", path(crf.where(subject_id: sub.subject_id).first %>
<% end %>
I also tried :
<%= link_to "edit", #CRF_PATH[crf](crf.where(subject_id: sub.subject_id).first %>
Which didn't work. I feel I must be getting close, any help or insight would be greatly appreciated.
Thanks.
A few things:
a. You should save yourself some time and loop through the dictionary instead of the array:
<% #CRF_PATH.each do |crf, path| %>
...
<% end %>
b. You are getting a string from the loop - you can invoke the equivalent method with send:
<%= send(path, ...) %>
c. You can simplify your retrieval of the objects using:
crf.find_by(subject_id: sub.subject_id)
That said - this seems like a pretty bad way of doing things. I'd recommend instead adding a view helper:
def crf_path(crf)
case crf
when Baseline then baseline_path(crf)
...
end
With something like this you could use (notice changed the find_by to find_by! for safety as well):
<% #CRFS_TO_VIEW.each do |crf| %>
<%= link_to "edit", crf_path(crf.find_by!(subject_id: sub.subject_id) %>
<% end %>
Finally instance variables should NOT be named upper case. If you want to use a constant define it as a constant (otherwise use lower case names).
In the preview action in my controller, I have
#models = Model.all
In the view, Im trying to loop through all the models, draw out their associated images, and use those to link_to their own profiles.
<% #models.each do |m| %>
<div> <%= link_to(image_tag (m.avatar.url(:thumb)), model_path())%> </div>
<% end %>
I need to pass in the id of each model to the route. Using m.id doesn't work because the route is expecting a hash.
Not entirely sure how to do this. Other posts on SO refer to unsaved instances and such, which aren't really relevant to this.
Try changing your view code from this:
<% #models.each do |m| %>
<div> <%= link_to(image_tag (m.avatar.url(:thumb)), model_path())%> </div>
<% end %>
To:
<% #models.each do |m| %>
<div> <%= link_to(image_tag(m.avatar.url(:thumb)), model_path(m))%> </div>
<% end %>
As usual the error might be in a completely different place - your brackets.
model_path can accept both list of attributes and a hash. Most likely you think it is expecting a hash due to the error message (which you should include in the question). In fact however, you are passing the path to the image_tag, not to the link_to:
link_to(image_tag (m.avatar.url(:thumb)), model_path())
is parsed as
link_to( image_tag(m.avatar.url(:thumb), model_path()) )
While:
link_to(image_tag (m.avatar.url(:thumb)), model_path())
is parsed as
link_to( image_tag(m.avatar.url(:thumb)), model_path() )
This space between a method name and a bracket is a silent killer. It is a image_tag which is expecting a hash in a second argument. :)
That being said - it will still not work, but you should get a different problem now.
I am trying to pass a string to my view from controller like this:
controller:
def index
#str = 'foo'
end
view:
String: <% #str %>
The variable itself seems to arrive because I get no error. However, it arrives empty (only "String" is in html, nothing else). And it seems to work great with other built-in types, e.g. Time. What am I missing here? I use Ruby 2.2.1 and Rails 4.
As others have said, you need to use
<%= #str %>
I'll give you an explanation as well - you use <% %> for when you need to run some Ruby code that you don't want displayed to the screen. For example, you might have conditional logic like
<% if user_signed_in? %>
<%= #welcome_string %>
<% end %>
Use <%= %> when you want to output, drop the '=' for conditional logic or anything that doesn't need to display.
in your view
String: <%= #str %>
In view user following code:
String: <%= #str %>
In your view, use:
<%= #str %>
As the other users have pointed out, you need to use <%=
The = is an ERB flag to so export the result of the code inside of the tags and put it into the DOM.
If you want to put some logic into your page that you don't want to evaluate, you leave the = out.
<% if user_wants_to_see_output? %>
<%= "User will see this" %>
<% end %>
so I have a standard has_many through association in my models, very similar to the question here: Loop through ActiveRecord::Associations::CollectionProxy with each
I used the advice in that problem but I think I am having some trouble getting it through on my ERB file so that it shows up in my app. At the moment I have the following:
<%= #memberships.map do |a| %>
<%=a.name%>
<% end %>
In this scenario, the membership model is the one through which users and organizations have many though (#memberships = #user.organizations). So the #memberships.class returns
ActiveRecord::Associations::CollectionProxy::ActiveRecord_Associations_CollectionProxy_Organization
on the rails console. So the moment, in the browser the code returns on a page where the user is in two orgs:
orgone orgtwo["\n", "\n"]
I just don't know how to manipulate the proxy classes to return what I want. Thanks!
UPDATE:
I figured it out, I had to remove the = at the top of the block, and I added some styling with a comma:
<% #memberships.map do |a| %>
<h3><%=a.name %> <%= ", " unless a == #memberships.last %></h3>
<% end %>
If you want to print the name of each membership, what you want is
<% #memberships.each do |membership| %>
<%= membership.name %>
<% end -%>
The <% prefix in ERB executes code without appending the results to the output buffer, while the <%= prefix outputs the string representation of the result of the expression. Since each returns an enumerator, a <%= will return the string representation of the enumerator which is something like #<Enumerator:0xDEADBEEF.
A really simple question but I just can't seem to get it working.
There is only one Property included below but there could be more than one within Properties. How can I iterate through this hash and display just the Name of each Property?
{"GetPropertiesResponse"=>{"Properties"=>{"Property"=>{"Breakfast"=>"IN", "Country"=>"GB", "Currency"=>"GBP", "Id"=>"1834", "Name"=>"Hotel Name"}}}}
I've tried this in my view:
<% #json['GetPropertiesResponse']['Properties']['Property'].each do |property| %>
<%= property['Name'] %>
<% end %>
I'm getting this error:
no implicit conversion of String into Integer
If you are saying there might be more than one property hash then this should work:
<% #json['GetPropertiesResponse']['Properties'].each do |property, value| %>
<%= value['Name'] %>
<% end %>
I would use #each_value on this hash since you don't appear to be using the keys
<% #json['GetPropertiesResponse']['Properties'].each_value do |value| %>
<%= value['Name'] %>
<% end %>
Should work. Note that the second line is <%= value['Name'] %> and not <%= property['Name'] %>
P.S. On a different note, I don't know why you're using the key "Property" inside of your Properties hash. That just seems like a good way to confuse yourself in exactly this way. Your keys within the Properties hash should be something unique to the property they describe. Since each will be a property, the string "Property" doesn't help describe or differentiate.