So I was experiencing an error when I was attaching a collection_select to my form_for object like so:
<%= f.collection_select(:city_id, #cities, :id, :name, {:prompt => "Select a City"}, {:id => 'cities_select', multiple: true}) %>
and getting the error:
undefined local variable 'city_id'
But when I don't bind the select like so:
<%= collection_select(nil, :city_id, #cities, :id, :name, {:prompt => "Select a City"}, {:id => 'cities_select', multiple: true}) %>
It works fine.
I just want to understand the theory behind why one works and the other doesn't?
I think what's tripping you up, primarily, is the concepts you have of what's going on here.
Nothing is “binding” anything to anything by calling a method on a form helper object. There are form helper methods, like collection_select, that can be used to build HTML elements. There are form builders that have methods, like collection_select that build HTML form elements for a form tied to an object.
The issue you're having here is that the FormOptionsHelper#collection_select method and the FormBuilder#collection_select method are not the same method and do not accept the same arguments:
FormOptionsHelper#collection_select vs FormBuilder#collection_select
Pay particular attention to the arguments provided. It's also worth noticing that FormBuilder essentially delegates this work to the template (i.e. FormOptionsHelper) and adjusts the arguments as needed.
Related
In Rails 4 in view I have
<%= form_for #person do |f| %>
<%= f.collection_select :country_id, Country.order(:name), :id, :name, include_blank: "Select your country" %>
...
<% end %>
I'd like "Select your country" to be selected as default whenever the page is loaded. One way is to use javascript (select it after the dom is loaded). Is there an easier way like adding an option to collection_select?
Thanks.
As per the docs, it's the prompt option in the options argument:
collection_select(:post, :author_id, Author.find(:all),
:id, :name_with_initial,
{:prompt => 'Please select the author of this post'})
With collection_select on a form builder we omit the first argument, so in this case:
f.collection_select :country_id, Country.order(:name), :id, :name, {prompt: 'Select your country'}
I've 100% confirmed this as working on my own app running Rails 4.1.6, where prompt and include_blank do the same thing.
The way this works is Rails injects a null-valued <option> as the first item in the generated <select> (this is because the HTML spec has nothing analogous to placeholder on text inputs for select inputs).
Reasons this may fail:
Rails does not mark the prompt option with the selected attribute, and I suspect some browsers may choose to render their own blank entry instead of the first in the list
If, for existing records, Rails determines that the current record's country_id matches an element in the list it will mark that one as selected. This is expected behaviour but can be a pain if you're doing anything non-standard.
If you're being bitten by these problems your options are to build the form manually (the method options_from_collection_for_select may be of use here) or do it in javascript. There is also an undocumented default attribute you can add to an <option> tag but it's not in the spec and browser support may be patchy, and you'd still have to build the form manually.
Is it possible to somehow use the :selected option that you'd use on a normal select view helper with the grouped_collection_select function? I'd like to set the value that gets pre-selected in my list. I've tried passing in :selected as an option with no luck!
Here's some code snippts of my tests:
grouped_collection_select 'user[subscription_attributes]', :subscription_plan_id, Trade.order(:name).all, :subscription_plans, :name, :id, :display_name, { :include_blank => true, :selected => 5 }
grouped_collection_select 'user[subscription_attributes]', :subscription_plan_id, Trade.order(:name).all, :subscription_plans, :name, :id, :display_name, :include_blank => true, :selected => 5
Neither version works. No selected is set. I'm using this to set a value for a nested model. I'm using the railscasts dynamic select list methods: http://railscasts.com/episodes/88-dynamic-select-menus-revised
I couldn't get formtastic to play nicely with the group selects so I had to do it by hand but I don't keep this value selected when a user fails validations. I'd like to keep this set when they fix validation errors.
I just ran across the same problem and solved it using the option_groups_from_collection_for_select helper and the select helper documented at: http://api.rubyonrails.org/classes/ActionView/Helpers/FormOptionsHelper.html.
The first step is to create the grouped options. Taking your example, it should look like:
<% options = option_groups_from_collection_for_select(Trade.order(:name).all,
:subscription_plans, :name, :id, :display_name, 5) %>
Then I created the select object like:
<%= select('user[subscription_attributes]', :subscription_plan_id, options,
include_blank: true) %>
You could write it all out in one line, I just broke out the options into a separate variable to illustrate the two different methods.
Maybe too late, but the API documentation of grouped_collection_select states:
'The value returned from calling method on the instance object will be selected.'
So, you don't even have to specify a :selected option, since Rails will automatically select based on the current value of your attribute.
If subscription_plan_id has value 5, then that's what will be selected.
If that's supposed to be a default value, then you can set it with an after_initialize in your model.
Actually you need to send in options include_blank for example
<%= grouped_collection_select :id, model.all, options = {:include_blank => 'Selecione'}%>
My question is how to set a field in rails form read only. The following is a selection box in quotes controller. Users are not allowed to change the selection.
<% #quote.test_items.each do |t| %>
<%= f.association :test_items, :label => false, :selected => t.id %>
<% end %>
The app uses simple_form. Thanks so much.
I've encountered a similar problem, thankfully, there is a simple resolution.
The basic issue is that if you use :disabled => true with simple_form you will not see that value back in the controller. When you pass an object from HTML form to later bind it to the model - you need all of those attributes. The :disabled => true however does not pass any such attribute.
The solution to this is to use :readonly => true - it will protect the field from user entry and it will still pass the param value back to the controller so you can bind everything to your model.
Good luck.
See https://github.com/plataformatec/simple_form/pull/367
I believe you'd just pass in :disabled => true. It's been my experience that options 'just work' with simple_form. So in your case:
<% #quote.test_items.each do |t| %>
<%= f.association :test_items, :label => false, :disabled => true, :selected => t.id %>
<% end %>
From the simple_form github repo:
It is also possible to give the :disabled option to SimpleForm, and it'll automatically mark the wrapper as disabled with a css class, so you can style labels, hints and other components inside the wrapper as well.
Yes, what #gk0r said, as it is documented here:
NOTE: The HTML options disabled, readonly, and multiple can all be treated as booleans. So specifying :disabled => true will give disabled="disabled".
*disabled will have slightly different behavior than readonly.
The top answers above are all wrong.
disabled attribute has a different behaviour than readonly.
read and compare them:
http://www.w3schools.com/tags/att_input_disabled.asp
Tip: Disabled elements in a form will not be submitted.
http://www.w3schools.com/tags/att_input_readonly.asp
The right answer is to use
:readonly => true
something like this:
<%= f.association :test_items, :label => false, :readonly => true, :selected => t.id %>
It's not clear to me if the association method accepts HTML options or not, but if it does, you can pass disabled: 'disable' to make it read-only with a fixed value.
I think you might be able to choose the fixed value by passing association as block, as shown in the association docs:
f.association :company do |c|
c.input :name, selected: 'selection'
c.input :type
end
As to whether or not the entire list can be read-only and still drop-down, the only solutions I see from google involve JS, for example:
http://techeyes.blogspot.com/2007/11/making-html-select-readonly.html
(Using Rails 2.3.5 on an internal work server with no choice of versions, and I'm pretty new)
I'm building a search form where I need to provide a list of directories to a user so they can select which one(s) to search against. I'm trying to figure out how to get the selected values of a collection_select to remain after the form is submitted.
Say the user selected 3 directories from the collection_select, the id's of those directories would look like this in the params:
directory: !map:HashWithIndifferentAccess
id:
- "2"
- "4"
- "6"
I know that you can manually specify multiple selected items:
<%= collection_select :directory, :id, #directories, :id, :name,
{:selected => [2,4,6]}, {:size => 5, :multiple => true} %>
I've also played around a bit and was able to us "to_i" against a single value in the params hash:
<%= collection_select :directory, :id, #directories, :id, :name,
{:selected => params[:directory][:id][0].to_i}, {:size => 5, :multiple => true} %>
What I can't figure out is how to use all of the values of the :directory params at the same time so what the user selected remains after the form is submitted. Thanks for any help.
I'm not precisely sure what you're asking, but if you're trying to get the array of strings in params[:directory][:id] as an array of integers, all you need is
params[:directory][:id].map{|id|id.to_i}
I have a Rails 2.3 web application that uses the collection_select helper with :multiple => true to handle a habtm relationship. This is working fine to set one or multiple values, however I have not figured out how to allow to REMOVE all selections.
Code:
<%= f.collection_select :category_ids, Category.find(:all), :id, :name,
{ :selected => #entry.category_ids },
{ :multiple => true, :name => 'entry[category_ids][]' }
%>
Once the user has ever set a category for an entry, how would I go about allowing it to be removed, so that this entry has no category? Is this possible with collection_select or would I need to add a checkbox to handle this specially?
P.S: I already tried with :prompt, :include_blank and :allow_blank, but as far as I could see neither of them did anything.
In your controller's update action, put in the following line:
params[:entry][:category_ids] ||= []
before the call to Entry.find.