Rails Form For Model Select Box With 1-dimensional Data

I want to limit the entry possibilities for a text field in my model to a previously defined array. How do I make an options_for_select with just a 1-dimensional array like ['foo',

Solution 1:

Basically, you want to be able to tie your collection select to a property of the object (in your case, @mappings)

Also, from the doc on rails collection_select, it will take options as follow:

collection_select(object, method, collection, value_method, text_method, options = {}, html_options = {}) public

• Objet: the object you are binding the selected option to (@mappings [f]) in this case
• method: The property/attribute of the object (in this case, mapping_type)
• collection: The collection for select ( ["foo","bar","foobar"] )
• value_method: The value you want to send back with the submit (Note that this is a method which means you should be able to call it on an object.) more on this later.
• text_method: The value you want to show as text on the select option on the view (this is also a method as above, more on this later as well)
• options: any additional option you want, (e.g: include_blank)
• html_options: eg: id, class etc.

As concerning the value_method and text_method, these are methods that should be called on your collection, which means that your collection will be an array of objects.

To this end, you can have the following:

classCollectionArrinclude ActiveModel::Model

  attr_accessor:name
  ARR = [
    {"name" => "foo"},
    {"name" => "bar"},
    {"name" => "foobar"}
  ]

  def self.get_collection
    ARR.collect do|hash|self.new(
        name: hash['name']
      )
    endendend

From here, calling CollectionArr.get_collection will return an array of objects where you can cal .name to return either foo, bar, or foobar. This makes using the collection_select and easy deal from here:

<%= f.collection_select : mapping_type, CollectionArr.get_collection, :name, :name, {:include_blank => "Select one"} %>

And all is green...