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Closed 9 years ago.
Can anybody tell, why this code works?
<% #products.each do |p| %>
<%= link_to p.name, product_path(p.id), :class => "title" %>
<%end%>
And this doesn't?
<% #products.in_groups_of(2).each do |product_array| %>
<% product_array.each do |p| %>
<%= link_to p.name, product_path(p.id), :class => "title" %>
<% end %>
<%end%>
The code gives error of undefined method `name' for nil:NilClass.
I am not getting clue of it. Can anybody help?
It appends nil if there is not enough records, that is why it gives nil:NilClass error
>> %w(1 2 3).in_groups_of(2) # => [["1", "2"], ["3", nil]]
>> %w(1 2 3).in_groups_of(2,false) # => [["1", "2"], ["3"]]
see in_groups_of(number, fill_with = nil)
<% #products.in_groups_of(2, false).each do |product_array| %>
<% product_array.each do |p| %>
<%= link_to p.name, product_path(p.id), :class => "title" %>
<% end %>
<%end%>
It sounds like you have an odd number of products. If you try and split an odd number into groups of two, the final product in the last group will be nil. You can just add:
unless p.nil?
<%= link_to p.name, product_path(p.id), :class => "title" %>
end
to ensure that you have an instance.
Related
I am trying generate a code that tracks for documents that revolve within the organisation. I have done other codes for adding employees, adding document types and logging in now I am struggling on creating a document form and search from the document that I have created. This code is for searching:
controller#show
def show
#generate_documents = GenerateDocument.where('Reciever LIKE?',"%#{params[:search]}%")
# #generate_documents = GenerateDocument.all
end
views/show
<%= form_tag generate_document_path, :method => :get do %>
<p>
<%= text_field_tag :search, params[:search] %>
<%= submit_tag "Search" %>
</p>
<% end %>
<!-- end of seaerch form -->
<!-- loading data from database and displaying then in a list format BEGIN -->
<ul>
<% #generate_documents.each do |generate_document| %>
<li>
<%= link_to generate_document.Reciever, edit_generate_document_path(generate_document) %>
</li>
<% end %>`enter code here`
</ul>
<!--
END LISTING -->
<%= link_to 'New Generate Document', new_generate_document_path %>
Even Iam new to rails, but i can help you with basics that you need to pass the parameters from the view to the controller, therefore you can use:
:url => {:controller => "name_of_your_controller", :action => "action_to_be_perforemed", :id => "whatever id you want"}
or else you can also pass the object within the url like we do while edit request
<%= link_to "Edit", edit_post_path(#edit)%>
which will give the :id of the particular post.
Hope this may help you.
I am having a problem with the tutorial of codelearn
See here
I have a form
<%= form_for :complete, :url => "/todos/complete", :method => :post do |f| %>
<% #todo_items.each do |t| %>
<%= f.check_box :todo_ids[], t.id %>
<%= t.todo_item %>
<% end %>
<%= f.submit "Complete todos", :class => "btn btn-success" %>
<% end %>`
I've got a problem with the symbol todo_ids[]. I get the error "wrong number of arguments (0 for 1..2)" at the line where it is written.
I tried another way with form_tag but that does not change a thing, I still get the error.
What I don't understand is that they don't have this problem in the tutorial.
Please do you have any idea ?
Many thanks
If there are semantic errors in the form (mostly from external API), I'd like to add an explanatory message, like so:
<%= semantic_form_for #order, :url => checkout_purchase_url, :html => {:class => 'payment'}, :wrapper_html => { :class => "field" } do |f| %>
<% if f.has_errors? %>
<p>There were errors that prevented your order from being submitted. If you need assistance, please contact us toll-free at <strong>1-800-555-5555</strong>.</p>
<%= f.semantic_errors %>
<% end %>
<% end %>
However, has_errors? is a protected method. Is there a way that I can do this? Thanks.
If you have nested attributes you won't see any errors associated with them. To ensure you get all base errors and any nested attributes errors. Make sure your model contains:
validates_presence_of :nested_object
validates_associated :nested_object
and in your form:
f.semantic_errors *f.object.errors.keys
Not as hard as I thought. I fixed it by checking for errors on the object instead of the form:
<% if #object.errors.any? %>
<p>There were errors that prevented your order from being submitted. If you need assistance, please contact us toll-free at <strong>1-800-555-5555</strong>.</p>
<%= f.semantic_errors %>
<% end %>
Thanks for those who viewed.
For completeness, here's an alternative approach if you want to show similarly helpful messages on each field:
= f.label :title
- if f.object.errors.any?
.error = f.object.errors[:title].flatten.join(' and ')
= f.text_field :title
This gives a nicely formatted and easily-styled list of errors for each field. (You can use semantic_errors instead of object.errors if you prefer, same result.)
Let's say I have a schema in which an apple crate contains zero or more apples. While editing the apple crate in a form, I want to list the apples and provide a checkbox next to each apple, for deleting it when the form is submitted.
There is nothing going wrong that I can see. In my model I say
class AppleCrate < ActiveRecord::Base
has_many :apples
accepts_nested_attributes_for :apples, :allow_destroy => true
...
end
I have the form working, so far as I can tell. The checkboxes appear in the form html and when the form is processed by the controller each apple in the list has an attribute called "_destroy" which is set to either "1" or "0" depending on whether or not I checked the box before submitting.
According to the Rails API, when I set _destroy to 1 and save, the apple should be deleted. But when I submit the form I get
ActiveRecord::UnknownAttributeError in AppleCrateController#update
unknown attribute: _destroy
...
"apple_crate"=>{"id"=>"10101", "apples"=>{"1"=>{"id"=>"1",
"variety"=>"granny smith",
"apple_crate_id"=>"10101",
"_destroy"=>"1"},
"2"=>{"id"=>"2",
"variety"=>"fuji",
"apple_crate_id"=>"10101",
"_destroy"=>"1"},
"3"=>{"id"=>"3",
"variety"=>"macintosh",
"apple_crate_id"=>"10101",
"_destroy"=>"0"},
...
and so on.
I must be missing something obvious but after several days of futzing around I can't figure it out. I can successfully do everything else -- update, edit, index, etc -- so long as I leave out the :_destroy attribute. Any ideas?
(For what it's worth, I'm running rails 3.2.2 on Windows.)
Updated:
This is what I'm looking at in the documentation. (See the subsection "One-to-many".)
Updated:
As requested in comments, here is the view:
<%= form_for #apple_crate do |f| %>
<% #apples = #apple_crate.apples %>
<% #apples.each do |apple| %>
<%= fields_for "apples[]", apple do |apple_fields| %>
<%= apple_fields.text_field :variety %>
<%= apple_fields.hidden_field :apple_crate_id %>
<%= apple_fields.hidden_field :id %>
<%= apple_fields.check_box :_destroy %>
<% end %>
<% end %>
<%= f.submit "Save" %>
<% end %>
You should generate nested forms and forms with rails helpers, don't do it by your hands. So I think that's where your error at.
Try:
<%= form_for #apple_crate do |f| %>
<%= f.fields_for :apples do |apple_fields| %>
<%= apple_fields.text_field :variety %>
<%= apple_fields.hidden_field :apple_crate_id %>
<%= apple_fields.hidden_field :id %>
<%= apple_fields.check_box :_destroy %>
<% end %>
<% end %>
something like this, did not check if it's correct, but idea should be clear enough
I'm trying to build a form that will list all users and allow you to check the ones that you want to add to a team. Here's my first cut at the form:
<div id="add_team_mates">
<%= form_tag do %>
<%= will_paginate #users %>
<ul class="users">
<% #users.each do |user| %>
<li>
<%= gravatar_for user, :size => 30 %>
<%= link_to user.name, user %>
<%= check_box_tag("add", user.id) %>
</li>
<% end %>
</ul>
<%= submit_tag "Add Team Mates", :action => "add_team_mates" %>
<% end %>
</div>
And, right now this is all that I have in the controller:
def add_team_mates
end
The problem is that if I check multiple users, I only get the last user.id rather than multiple is as I'd expect. Here's some example from the log:
Started POST "/teams/5" for 127.0.0.1 at 2011-04-14 15:28:13 -0700
Processing by TeamsController#add_team_mates as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"IHFDevfKES8NibbCMlRa1t9qHn4/ZMKalK1Kjczh2gM=", "add"=>"3", "commit"=>"Add Team Mates", "id"=>"5"}
Completed in 12ms
Any help on this would be greatly appreciated. Thanks!
All your checkboxes have the same name, change the line to
check_box_tag("add[]",user.id)
In the controller your parameters will be like so:
params[:add] = ['foo','bar','baz']