Rails 4 How to assign value to dropdowns in a hash? - ruby-on-rails

For example I need to create a dropdown with options "Sedentary", "Lightly Active", "Active", "Very Active" and assign those to a user as an integer(0, 1,..3). How can I make a hash
activity_level = {"Sedentary" => 0,
..............,
"Very Active" => 3}
and store an integer value instead of a string?

Try this
f.input :fieldname, as: select, collection: activity_level.keys
When saving it
your_model_object.attribute = activity_level[params[:selected_value]]
your_model_object.save

Best option IMO would be using the Rails enum feature, which maps integer to string values:
class Activity < AR::Base
enum :activity_level => [ :sedentary, :lightly_active, :active, :very_active ]
def self.activity_levels # or store in an I18n.
{ "sedentary" => "Sedentary", "lighty_active" => "Lightly Active", ...}
end
AR will store that columns internally as integer, but you have never to deal with this. You can also use the convenient query methods, like Activity.sedentary.where... or if #activity.sedentary?
And the form (When I remember correctly, the collection needs to be pairs of [v, k] not [k, v], so "Lightly Active" => "lightly_active"):
= f.input :activity_level, as: :select, collection: Activity.activity_levels.map(&:reverse)

Related

Rails 4 -Simple Form how to save key and display value

I'm trying to make an app in Rails 4. I use simple form for forms.
I have an attribute called 'self_governance' in my model.
I've written a helper method so that I can define 5 levels which can be stored for this attribute, but which are displayed to the user as options (rather than numbers 1 .. 5).
In my helper, I have:
module PreferencesHelper
def self_gov_selector
[
[ 'tier 1','1'],
[ 'tier 2','2'],
[ 'tier 3','3'],
[ 'tier 4','4'],
[ 'tier 5','5'],
]
end
In my form, I then have:
<%= f.input :self_governance, :label => "Select your tier", collection: self_gov_selector %>
Then in my show, I'm trying to figure out how to display 'tier 1' instead of '1'.
I have tried:
<%= #preference.self_governance %>
<%= #preference.self_gov_selector %>
I can't find anything that works. They all display 1 instead of Tier 1 in the views.
How can I make this work?
The params posted by the form will only include the second value in the array, so you're likely storing your value as an integer in your database table.
A simple solution is to use an enum to map the integers you're storing to the values they represent:
In your Preference model:
enum self_governance: {
tier_1: 1,
tier_2: 2,
tier_3: 3,
tier_4: 4,
tier_5: 5
}
Then update your view accordingly:
<%= #preference.self_governance.try(:humanize) %>
EDIT:
An additional bonus of this approach is that you can replace your helper method with calling the enum directly:
f.input :self_governance, as: :select, label: "your label", collection: Preference.self_governances.map { |key, val| [key.humanize, val] }

Rails passing in variables into view helper methods from form selection

I have a bit of code in my user.rb model like this:
def self.aggregate(articles)
array = []
articles.each do |a|
array << {
:id => a.nid,
:views => a.daily_view_metrics.sum_views(a.nid),
:date => a.daily_view_metrics.latest_date(a.nid),
:title => a.daily_view_metrics.latest_title(a.nid),
:visits => a.daily_view_metrics.sum_visits(a.nid)
}
end
return array
end
In my user_controller I pass into the show method #metrics = User.aggregate(#articles) (#articles being simply a subset of articles for that user)
Now in my view (user#show) i call #metrics.each do |m| and then output all the different things in a table. Now according to this video it seems that the link_to method with a url parameter seems to be the best way to have users dynamically switch what they want to sort against.
How can I input that url parameter to sort the array? I tried calling #metrics.sort_by{|h| h[params[:sort]]}.each do |m| with :sort being the url parameter from my links (i.e. the views table header link click passes :sort => ":views" in. Essentially I am trying to do this sort_by{|h| h[:views]} since that works fine for sorting the array. However nothing happens. The array isn't sorted.
EDIT:
I solved it by making the aggregate method pass the key in as a string (i.e. "id" as opposed to :id). then the url params works beautifully.
<%= link_to "Views", :sort => "views"%> now sorts it by views in ascending order.
To order in descending mode you can negate - the element that you are using to sort by.
Ordering by ascending and then do revert to your collection is inefficient.
For instance
$> [{a: 'a1', b: 1}, {a: 'a2', b: 2}].sort_by{ |h| -h[:b] }
# => [{:a=>"a2", :b=>2}, {:a=>"a1", :b=>1}]
$> [{a: 'a1', b: 1}, {a: 'a2', b: 2}].sort_by{ |h| h[:b] }
# => [{:a=>"a1", :b=>1}, {:a=>"a2", :b=>2}]
In the form of your view, you will have something like this (a RadioButton e.g but it could be a Select or whatever you prefer):
<%= radio_button_tag 'radio_order', 'ascending', true %> Ascending
<%= radio_button_tag 'radio_order', 'descending' %> Descending
<%= submit_tag "Order" %>
Then in your helper get the value using params[:radio_order]:
aggregate('views', params[:radio_order])

Get key names from key value pairs

I'm running Rails 4 on Ruby 2.0
I'm trying to populate a select tag with a key value pair array I have setup in my model. However, I am having trouble figuring out how to grab the key. Here is what I have so far:
Model
class Store
Colors = ['blue', 'green', 'red', 'yellow', 'orange', 'pink', 'purple', 'lime', 'magenta', 'teal']
SearchParams = {'isbn' => 'ISBN', 'intitle' => 'Title', 'inauthor' => 'Author', 'inpublisher' => 'Publisher', 'subject' => 'Subject', 'lccn' => 'LCCN', 'oclc' => 'OCLC'}
end
Controller
def index
#search_params = Store::SearchParams.map { |param| [param, param.key] }
end
note: I am aware that .key does not exist - I added that hoping it would better communicate what I am trying to do.
View
<%= form_tag do %>
<%= select_tag :param_name, #search_params, prompt: 'choose' %>
<% end %>
I would like the value of each <option> to be the key, and for the user to see the value. I hope that makes sense.
You generally use options_for_select to provide the options for select_tag. Conveniently, you can hand a Hash to options_for_select and it will do the right thing:
options_for_select(container, selected = nil)
Accepts a container (hash, array, enumerable, your type) and returns a string of option tags. [...]
The problem is that options_for_select wants the Hash's keys to be what the human sees and the values to be the value attributes for the <option>s. Your Hash is backwards but you can use Hash#invert to flip the keys and values around:
invert → new_hash
Returns a new hash created by using hsh’s values as keys, and the keys as values.
So you could just do this in your controller:
#search_params = Store::SearchParams.invert
and then this in the ERB:
<%= select_tag :param_name, options_for_select(#search_params), prompt: 'choose' %>
I think, this itself will work
def index
#search_params = Store::SearchParams.to_a
//it will return the array you want, but the values will be [[key1,value1],[key2,value2]]
// if you want to reverse itm then Store::SearchParams.to_a.collect{|arr| arr.reverse} will give that
end
That will do it:
def index
#search_params = Store::SearchParams.map { |key, val| [val, key] }
end
UPD: consider also Hash#invert (thanks to #mu is too short)

In Rails 3 how should I manage a model column with limited choices

In my Rails 3 application I have numerous models that have columns that have limited choices (IE a select box). It seems overkill in these cases to create another model and a relationship to the original model just to manage the choices.
One option I can think of is to just create a select box and have the choices in there, but that doesn't seem very DRY. Does anyone have a good suggestion how to handle this situation?
Thanks for looking.
You could create a constant in your model like so
# formatted as an array of options, option being an array of key, value
OPTIONS = [['Email', 'email'], ['Text', 'text'], ['Email and Text', 'both']]
validates_inclusion_of :field, :in => OPTIONS
Which can then be used to populate a select menu in a view very easily
Example using formtastic
<%= f.input :field, :as => :select, :collection => Model::OPTIONS %>
I usually do this with a constant list in the model.
class Model < ActiveRecord::Base
PROPERTY_OPTIONS = ['Option One', 'Option Two', ...]
validates_inclusion_of :property, :in => PROPERTY_OPTIONS
end
And in the view:
<%= f.select :property, Model::PROPERTY_OPTIONS %>
You can also use the enum_column plugin: https://github.com/electronick/enum_column
You can then render your select boxes in your views as follows:
<%= f.select :status, Model.columns_hash['status'].limit %>
(Where Model is an example model name, such as Book or Product, or whatever it is your application is really about.)
In some cases, I will just create a hash of options and use Class Methods to display and set them. For example, a Problem model with different statuses could be done like so:
def self.statuses
{:open => 1, :closed => 2}
end
Then you just store the integer value in the status_id of the model. You can configure getters/setters as well.

multiparameter error with datetime_select

I have the following code in my form.
<%= f.datetime_select(:date_time, :prompt => {:day => 'Day', :month => 'Month', :year => 'Year'}, :start_year => Date.today.year, :end_year => Date.today.year + 2, :minute_step => 15, :include_blank => false) %> if either one is blank.
When one of the fields is left blank, I get:
1 error(s) on assignment of multiparameter attributes
The params that are being passed are:
{"utf8"=>"✓",
"authenticity_token"=>"kQpfsj5RxnDtxkvBdwPEFnX1fY6euKnMQeDRAkvJvIE=",
"event"=>{"description"=>"",
"venue"=>"",
"street"=>"",
"city"=>"",
"country_id"=>"",
"date_time(1i)"=>"",
"date_time(2i)"=>"",
"date_time(3i)"=>"",
"date_time(4i)"=>"00",
"date_time(5i)"=>"00",
"ticket_url"=>""},
"x"=>"94",
"y"=>"12"}
Anyone know why this is occurring?
There seems to be a "dirty" fix for this at this link, but perhaps there is a better solution in Rails 3?
Christian. This is a bug in Rails that checks the database to infer the type needed for the multiparameter attributes. My guess is that your "date_time" attribute is not associated with a time column in your database.
I recently tackled this problem where I wanted a non-database attribute to accepted multiparameter attributes, this was the best solution I could come up with:
I found myself wanting to set an attr_accessor to handle passing a date to my model in a form_for tag with the f.datetime_select helper. So this is what I had:
Model:
attr_accessor :my_time
View:
<%= f.datetime_select :my_time %>
Unfortunately when I submit my form I get this:
1 error(s) on assignment of multiparameter attributes
Well it turns out that this is actually a Rails bug a ticket for which has been submitted. In the meantime how do we make this work? The only solution I could find that was remotely attractive was to make use of composed_of as a replacement for attr_accessor. so...
Model:
composed_of :my_time,
:class_name => 'Time',
:mapping => %w(Time to_s),
:constructor => Proc.new{ |item| item },
:converter => Proc.new{ |item| item }
I know almost nothing about the composed_of method so you should probably do your own reading on it, but what I do know is that it creates both a reader and writer for the given instance variable, and more importantly, the setter accepts multiparameter attributes. How I chose the options:
class_name: the name of our expected class. In this case, Time
mapping: the first argument is the class and the second argument seems to work with any method that an instance of the class responds to. I chose to_s
constructor: Not really sure how this is supposed to work. Seems to be called when #my_time is nil.
converter: Not really sure how this is supposed to work. Seems to be called when from my_time=, but doesn't seem to be applied with mass assignment.
One problem I ran into with this solution was that times were getting set in UTC instead of the environment's time zone. So unfortunately we cannot use my_time directly, but instead need to convert it to the proper time zone:
Time.zone.parse(my_time.to_s(:number))
What Does ActiveRecord::MultiparameterAssignmentErrors Mean?
def initialize(attributes={})
date_hack(attributes, "deliver_date")
super(attributes)
end
def date_hack(attributes, property)
keys, values = [], []
attributes.each_key {|k| keys << k if k =~ /#{property}/ }.sort
keys.each { |k| values << attributes[k]; attributes.delete(k); }
attributes[property] = values.join("-")
end
I had the same problem using a date dropdown that wasn't backed by a database attribute. I wrote a little Rack middleware to cope with the problem:
class DateParamsParser
def initialize(app)
#app = app
end
def call(env)
if %w{POST PUT}.include? env['REQUEST_METHOD']
params = Rack::Utils.parse_query(env["rack.input"].read, "&")
# selects only relevant params like 'date1(1i)'
filtered_params = params.select{ |key, value| key =~ /\(\di\)/ }
# delete date params
filtered_params.each { |key, value| params.delete(key) }
# returns something like {'date1' => [2012, 5, 14], 'date2' => [2002, 3, 28]}
date_array_params = filtered_params.sort.reduce({}) do |array_params, keyvalue|
date_key = keyvalue.first.match(/(.+)\(/)[1] + ']'
array_params[date_key] ||= []
array_params[date_key] << keyvalue.last
array_params
end
# Creates params with date strings like {'date1' => '2012-5-14', 'date2' => '2002-3-28'}
date_params = Hash[date_array_params.map{ |key, date_array| [key, date_array.join('-')] }]
params.merge! date_params
env["rack.input"] = StringIO.new(Rack::Utils.build_query(params))
env["rack.input"].rewind
end
#app.call(env)
end
end
And in application.rb I put
config.middleware.insert_before ActionDispatch::ParamsParser, "DateParamsParser"
Note that I only build a date string here. So if you also require time you'll need to build the date_params differently.
I faced the same problem with the model below
class Reservation < ActiveRecord::Base
attr_accessor :sid, :check_in, :credit_card_number, :expiration_date
attr_accessible :expiration_date
end
The corresponding form with the field for the expiration date:
<div class="field">
<%= f.label :expiration_date %>
<%= f.date_select(:expiration_date, start_year: Time.now.year + 3, :end_year => Time.now.year - 3, discard_day: true) %>
</div>
as mentioned by #gabeodess the problem is checking the database to infer the type accordingly the solution I did for it was adding the following code to the model to put the type of the needed attribute in this case :expiration_date so the model is modified to be the following
class Reservation < ActiveRecord::Base
attr_accessor :sid, :check_in, :credit_card_number, :expiration_date
attr_accessible :expiration_date
columns_hash["expiration_date"] = ActiveRecord::ConnectionAdapters::Column.new("expiration_date", nil, "date")
end
Hope this is useful
Remove :include_blank => false from your code.
<%= f.datetime_select(:date_time, :prompt => {:day => 'Day', :month => 'Month', :year => 'Year'}, :start_year => Date.today.year, :end_year => Date.today.year + 2, :minute_step => 15 %>
Thanks....
I was facing the same problem.
I just added attr_accessible for that attribute and it works fine.
Hope it helps.

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