My example form
<% form_for #ad do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :ad_type_id %><br />
<%= f.collection_select(:ad_type_id, AdType.all, :id, :name) %>
</p>
<p>
<% #ad.ad_properties.each do |property| %>
<%= property.name %>:
<% f.fields_for :ad_values do |value_field| %>
<%= value_field.text_field :ad_id, :value => #ad.id %>
<%= value_field.text_field :ad_property_id, :value => property.id %>
<%= value_field.text_field :value %>
<% end %><br /><br />
<% end %>
</p>
<p>
<%= f.label :description %><br />
<%= f.text_area :description %>
</p>
<p><%= f.submit %></p>
<% end %>
Explanation:
Ad has many properties. I can add new properties at any time (it's a normal model).
Lets say the Ad is of the type 'hotel'. Then I would add properties like 'stars' and 'breakfast_included'
Then I store each of these properties' values in a separate model.
And all this works fine with my form above.
My problem:
These fields are not validated because I can't know what their names are.
I need to add validations dynamically somehow.
My thought:
#Before the normal validations kick in
def add_validations
self.properties.each do |property|
property.add_validation :whatever #somehow :)
end
end
How could I do this?
Have you tried with polymorphic associations ? That's maybe a cleaner approach.
http://railscasts.com/episodes/154-polymorphic-association
Disclaimer: I've never done this before, so I'm not 100% sure it will work.
But as long as you can get the type of the object you are working with, you can use the Rails constantize method to get the model it references (I'm assuming that if ad can be of type Hotel, then you have a Hotel model). At that point you should probably have the appropriate validations on your Hotel model.
Related
I have following two resources:
Position
JobTitle
And a position belongs_to job title.
In page Position, I create new position, with job_title select and some other selects. I need also create new job_title in this page, instead of choose select variants. So, in fact, or I choose job title in existing base, or create new, and save it for this position.
How can I make this? I looking for answer, and reading docs, but nothing!
You need to use fields_for in your view to send params for two models at a time.
Here's how I would try to solve to problem:
<%= form_for #job_title do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<p>
<%= f.label :description %><br />
<%= f.text_field :description %>
</p>
<%= f.fields_for :position do |builder| %>
<p>
<%= builder.label :name %> <br />
<%= builder.text_field :name %>
</p>
<% end %>
<p><%= f.submit "Submit" %></p>
<% end %>
And then, in your controller, you need to create the association. For more information, you can check out the railscast for nested forms.
I have a simple Rails form that uses a conditional build_association (if there's not already an associated parent) to include a text_field to edit a parent. This is useful if a new record for the parent should be added. The problem with this is that if a parent already exists, if the text_field is updated then it will be changed for the parent record affecting many children. If build_association is called regardless of whether a parent association already exists, then new, duplicate parents will constantly be created.
I am trying to understand how I can use build_association and fields_for to add a new parent to the database if the user types in an unfamiliar name, but to set the parent to be an existing record if the name matches an existing parent's name. (If I can get this part to work right, the next step will be to add autocomplete.) The code is below:
<%= form_for #sermon, :html => { :multipart => true } do |f| %>
<div class="field">
<%= f.label :title %><br />
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :date %><br />
<%= f.text_field :date %>
</div>
<div>
<% #sermon.build_speaker unless #sermon.speaker %>
<%= f.fields_for :speaker do |g| %>
<%= g.label :name, "Speaker name:" %><br />
<%= g.text_field :name %>
<%= g.submit %>
<% end %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
I think my gem get_or_build will be useful for you. I had the same problem and didn't find any appropriate clean solution so I've decided to write this gem. Enjoy!
I have a model "tube" which is a database having the various data for vacuum tubes. I want to dynamically loop through all the columns and create a basic table for my "new" and "edit" pages.
I grab the attribute names like this:
<% attr_array = #tube.attribute_names %>
And I want to do something like this:
<% attr_array.each{|x| text_field :x } %>
in hopes of dynamically generating this:
<%= form_for #tube do |f| %>
<%= f.label :name, :class=>'std_label' %>:
<%= f.text_field :name, :class=>'std_input' %>
<%= f.label :functional_class, :class=>'std_label' %>:
<%= f.text_field :functional_class, :class=>'std_input' %>
<%= f.label :base_type, :class=>'std_label' %>:
<%= f.text_field :base_type, :class=>'std_input' %>
.... and so forth ....
<%= f.submit %> <% end %>
But of course this does not work, not by a long shot. How can I generate my text_field inputs dynamically based on the attribute_names array? The table I am using has about 30 attributes and I think it's silly to build them all by hand, especially given that if they change in the future then the code will break. Googling and reading the API have given me the lectures on why this doesn't work, but has left me hi and dry with a code example of what does.
Accurate help appreciated.
What about:
<%= form_for #tube do |f| %>
<% #tube.attribute_names.each do |attr| %>
<%= f.text_field attr, :class=>'std_input' %>
<%= f.label attr, :class=>'std_label' %>:
<% end %>
<%= f.submit %>
<% end %>
I'm attempting to edit a model's nested attributes, much as outline here, replicated here:
<%= form_for #person do |person_form| %>
<%= person_form.text_field :name %>
<% for address in #person.addresses %>
<%= person_form.fields_for address, :index => address do |address_form|%>
<%= address_form.text_field :city %>
<% end %>
<% end %>
<% end %>
In my code, I have the following:
<%= form_for(#meal) do |f| %>
<!-- some other stuff that's irrelevant... -->
<% for subitem in #meal.meal_line_items %>
<!-- # Edit 2: I need to display information here about the subitem
Which I can't find a way to pass it to the partial, or work in
this manner for existing items
-->
<%= subitem.food.name %>
<%= subitem.food.calories %>
<%= f.fields_for subitem, :index => subitem do |line_item_form| %>
<%= line_item_form.label :servings %><br/>
<%= line_item_form.text_field :servings %><br/>
<%= line_item_form.label :food_id %><br/>
<%= line_item_form.text_field :food_id %><br/>
<% end %>
<% end %>
<%= f.submit %>
<% end %>
This works great, except, when I look at the HTML, it's creating the inputs that look like the following, failing to input the correct id and instead placing the memory representation(?) of the model. As a result, an update fails:
<input type="text" value="2" size="30" name="meal[meal_line_item][#<MealLineItem:0x00000005c5d618>][servings]" id="meal_meal_line_item_#<MealLineItem:0x00000005c5d618>_servings">
EDIT:
The reason I'm attempting to do it in this method is that I need to gather some information on associations for existing meal_line_items. For example, in the area where I took out code, I have some code to the effect of:
<%= subitem.food.name %>
<%= subitem.food.calories %>
Getting this information won't work if I am using a form builder with partials, at least, not in my trials.
Edit 2:*
See the edit in the code. Here's my MealLineItem
class MealLineItem < ActiveRecord::Base
# Associations ---------------------
belongs_to :food
belongs_to :meal
end
And meal accepts_nested_attributes for the model. As you can see it belongs to both food and meal model. For the existing meal_line_item I need to do something like:
meal_line_item.food.name
Is there f. missing from <%= fields_for?
--edit
Have you tried:
<%= f.fields_for 'meal[meal_line_item][]', subitem do |line_item_form| %>
--edit
Docs say that it should work without loop too:
<%= form_for(#meal) do |f| %>
<!-- some other stuff that's irrelevant... -->
<%= f.fields_for :meal_line_items do |line_item_form| %>
<%= line_item_form.label :servings %><br/>
<%= line_item_form.text_field :servings %><br/>
<%= line_item_form.label :food_id %><br/>
<%= line_item_form.text_field :food_id %><br/>
<% end %>
<%= f.submit %>
<% end %>
Have to test this but maybe this approach?
_form
<%= form.fields_for :meal_line_items do |meal_line_item_form| %>
<% #meal.meal_line_items.each do |meal_line_item| %>
<%= render :partial => "meal_line_items/meal_line_item", :locals => { :meal_line_item_form => meal_line_item_form, :meal_line_item => meal_line_item } %>
<% end %>
<% end %>
meal_line_items/_meal_line_item.erb
<%= meal_line_item_form.label :servings %><br/>
<%= meal_line_item_form.text_field :servings %><br/>
<%= meal_line_item_form.label :food_id %><br/>
<%= meal_line_item_form.text_field :food_id %><br/>
EDIT
here's a link to an example for setting the formbuilder iterator directly (Rails 2.3.8 though). The associations between Outbreak -> Incidents -> Location should be similiar to the ones for Meal -> Meal_line_items -> Food.
AJAX update of accepts_nested_attributes_for partials
After searching high and low, I found the error. Although I was modifying the partial and was receiving a NameError it's because I was calling the partial from a helper method - exactly the same problem as stated in the following question:
rails fields_for render partial with multiple locals producing undefined variable
In Rails, how do I generate form labels without symbols that still create correct "for" attributes?
If I take this form:
<% form_for(#thing) do |f| %>
<%= f.error_messages %>
<p>
<%= f.label :name %><br />
<%= f.text_field :name %>
</p>
<p>
<%= f.submit 'Create' %>
</p>
<% end %>
And alter it to improve the clarity of what's expected in the field:
<% form_for(#thing) do |f| %>
<%= f.error_messages %>
<p>
<%= f.label "What would you like to call your thing?" %><br />
<%= f.text_field :name %>
</p>
<p>
<%= f.submit 'Create' %>
</p>
<% end %>
The for attribute on the label tag would read "thing_What would you like to call your thing?", which obviously destroys its relationship with the intended partner field.
So how do I alter the label text while preserving that relationship?
<%= f.label :name, "What would you like to call your thing?" %>
See label’s documentation (and on APIdock).