I am trying to use the gem countries from hexorx. I really don't know how to bring that in the select helper. I tried to use the helper country_select like this
<%= f.country_select :country, :required => true %>
The GitHub location of gem is https://github.com/hexorx/countries.
The interface for this helper is defined as:
country_select(object, method, priority_countries = nil, options = {}, html_options = {})
I found this by going to the link you supplied, navigating through the source code to /lib/countries/select_helper.rb
Assuming this is in a form_for operating on an object instance, perhaps #user then an instance of User is what gets passed for the first parameter, object. The second argument, method is the attribute of the object that should receive the selected value, so in this example, your User model will need to have an attribute called country.
So the problem is likely that the third argument expects a list of priority_countries, but it's getting :required => true. If you pass nil, then pass your options, it should work, like this:
<%= f.country_select :country, nil, :required => true %>
For future posts, when something doesn't work, you should provide the complete error message or symptoms that you saw. Please refer to the FAQ
Related
After adding the second method, uniq.pluck(:state) to the code below, I'm getting the following error message:
undefined method `state' for "AK":String.
I looked at all the posts on here and couldn't find anything related to this problem. Any insights or help you could offer would be greatly appreciated.
<%= f.collection_select :state, (Boli.order(:state).uniq.pluck(:state)), :id, :state, include_blank: true %>
Thank you #D-side, now having difficulties using grouped_collection. I'd like the user to be able to select a group of banks in a particular state. Getting the error message undefined method `map' for :id:Symbol, using the following code:
<%= f.grouped_collection_select :bank, :id, Boli.order(:bank), :id, :bank, include_blank: true%>
pluck with a single attribute name returns an array of attribute values. Strings, in your case.
collection_select, however, is built with model instances in mind, in that it accepts... well, the docs say it better anyway:
collection_select(method, collection, value_method, text_method, options = {}, html_options = {})
<...>
The :value_method and :text_method parameters are methods to be called on each member of collection. The return values are used as the value attribute and contents of each <option> tag, respectively. They can also be any object that responds to call, such as a proc, that will be called for each member of the collection to retrieve the value/text.
Obviously, since you've already fetched values of the attribute state, calling state on the resulting values once more is nonsensical.
You can fix this in multiple ways.
PostgreSQL's DISTINCT ON (expr)
By replacing .uniq.pluck(:state) with .select("DISTINCT ON (state) id, state") you'll get ActiveRecord model instances, so every element of the resulting collection will have methods id and state, as collection_select expects.
Or use the query you have, with pluck
...by giving procs instead of :id and :state that take a string as an argument and produce appropriate values.
It all boils down to what you need.
I have a select box for the event types of an event. event belongs to event_type and event_type has many events. Here's what I have for the select box:
<%= f.select :event_type, options_from_collection_for_select(EventType.all, :id, :name, #event.id), :placeholder => 'Select an event type' %>
But, the problem is that when I submit it, it submits the id of the event type and not the name of it. So, how would I make it submit the name rather than the id? If you need to see the any more code than just tell me, thanks
The second parameter to options_from_collection_for_select is the value that will be submitted with the form. You have :id, so change it to :name.
http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/options_from_collection_for_select
(but this seems like a strange thing to do - typically you would store the event type ID.)
You can use the id after the submit to load the event type again in your controller post action like this:
selected_type = EventType.find(params[:event_type]
It is also a good practice to keep database calls to the controller, so please put the EventType.all statement in there and pass it as local or class variable like you did with event.
If you really want to pass the name in your form instead of the id, you can replace the :id part in your call to something more like this options_from_collection_for_select(#event_types, :name, :name, #event.event_type.name). Keep in mind that this value should be unique!
The method works like this:
options_from_collection_for_select(collection, value_method, text_method, selected = nil)
So the first parameter contains all the options, the second defines the value within those option objects which are put into the value field of the HTML option (which is being submitted by the form), the third defines the text which is displayed to the user and the final parameter defines the value of the selected entry (in case you are editing an entry for example). For the last parameter, you need to use the events' event_type id, or in your case, the name because you set the value of your HTML tag to it.
Use pages like ApiDock or the Rails tutorials to get examples for some of these methods.
http://apidock.com/rails/ActionView/Helpers/FormOptionsHelper/options_from_collection_for_select
You should pass name in the Value method, if you want to pass the name,
<%= f.select :event_type, options_from_collection_for_select(EventType.all, :name, :name, #event.id), :placeholder => 'Select an event type' %>
Here is the doc for options_from_collection_for_select
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.
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'}%>
I am going through the Rails API docs for collection_select and they are god-awful.
The heading is this:
collection_select(object, method, collection, value_method, text_method, options = {}, html_options = {})
And this is the only sample code they give:
collection_select(:post, :author_id, Author.all, :id, :name_with_initial, :prompt => true)
Can someone explain, using a simple association (say a User has_many Plans, and a Plan belongs to a User), what I want to use in the syntax and why?
Edit 1: Also, it would be awesome if you explained how it works inside a form_helper or a regular form. Imagine you are explaining this to a web developer that understands web development, but is 'relatively new' to Rails. How would you explain it?
collection_select(
:post, # field namespace
:author_id, # field name
# result of these two params will be: <select name="post[author_id]">...
# then you should specify some collection or array of rows.
# It can be Author.where(..).order(..) or something like that.
# In your example it is:
Author.all,
# then you should specify methods for generating options
:id, # this is name of method that will be called for every row, result will be set as key
:name_with_initial, # this is name of method that will be called for every row, result will be set as value
# as a result, every option will be generated by the following rule:
# <option value=#{author.id}>#{author.name_with_initial}</option>
# 'author' is an element in the collection or array
:prompt => true # then you can specify some params. You can find them in the docs.
)
Or your example can be represented as the following code:
<select name="post[author_id]">
<% Author.all.each do |author| %>
<option value="<%= author.id %>"><%= author.name_with_initial %></option>
<% end %>
</select>
This isn't documented in the FormBuilder, but in the FormOptionsHelper
I've spent quite some time on the permutations of the select tags myself.
collection_select builds a select tag from a collection of objects. Keeping this in mind,
object : Name of the object. This is used to generate the name of the tag, and is used to generate the selected value. This can be an actual object, or a symbol - in the latter case, the instance variable of that name is looked for in the binding of the ActionController (that is, :post looks for an instance var called #post in your controller.)
method : Name of the method. This is used to generate the name of the tag.. In other words, the attribute of the object you are trying to get from the select
collection : The collection of objects
value_method : For each object in the collection, this method is used for value
text_method : For each object in the collection, this method is used for display text
Optional Parameters:
options : Options that you can pass. These are documented here, under the heading Options.
html_options : Whatever is passed here, is simply added to the generated html tag. If you want to supply a class, id, or any other attribute, it goes here.
Your association could be written as:
collection_select(:user, :plan_ids, Plan.all, :id, :name, {:prompt => true, :multiple=>true })
With regards to using form_for, again in very simple terms, for all tags that come within the form_for, eg. f.text_field, you dont need to supply the first (object) parameter. This is taken from the form_for syntax.