I'm trying to allow non-signed-in users to change a time of day display, and it seems like the best way would be through params in the url. I have:
class ApplicationController < ActionController::Base
around_filter :use_time_zone
private
def use_time_zone(&block)
Time.use_zone((params[:time] || Time.zone), &block)
end
end
And this works great for something like 'www.mysite.com?time=Hawaii'
However, it cannot handle some of the more intricate ones (e.g. 'Eastern Time (US & Canada)'), plus this looks bad in the address bar.
Is there a way to simply use UTC offset with DST (or any other abbreviated form like 'PDT') with params?
I solved this with a workaround, hopefully others may find it useful.
I created a helper to generate key/value pairs based on first 2 letters of time zone name:
# helpers/application_helper.rb
(...)
def tz_mapping
tzs = Hash.new
ActiveSupport::TimeZone.us_zones.reverse.each do |tz|
tzs[tz.name.to_s.first(2).downcase] = tz
end
tzs
end
Then I can pass those abbreviations in via params and pick it up in the controller:
# controllers/application_controller.rb
(...)
around_filter :use_time_zone
private
def use_time_zone(&block)
zones = { 'ha' => 'Hawaii',
'al' => 'Alaska',
'pa' => 'Pacific Time (US & Canada)',
'ar' => 'Arizona',
'mo' => 'Mountain Time (US & Canada)',
'ce' => 'Central Time (US & Canada)',
'ea' => 'Eastern Time (US & Canada)',
'in' => 'Indiana (East)' }
Time.use_zone((zones[params[:tz]] || Time.zone), &block)
end
So a simple view might look like
<% tz_mapping.each do |k,v| %>
<%= link_to v, root_path + "?tz=#{k}" %><br />
<% end %>
Which gives links to each scenario, and can be used as needed.
Related
At the moment I have a form in which the user can input price per person and/or duration and/or team_size. What I would like to accomplish is to retrieve all records from a table that match the user input and for this I set scope in the model:
scope :filter_by_team_size, -> (team_size) { where("team_size = ?", team_size) }
scope :filter_by_duration, -> (duration) { where("duration = ?", duration) }
scope :filter_by_price, -> (price) { where("price = ?", price) }
And then in the controller use that again to retrieve the records by doing so:
#experiences = policy_scope(Experience).order(team_size: :desc).geocoded.filter_by_team_size(params[:team_size]) if params[:team_size].present?
#experiences = policy_scope(Experience).order(duration: :desc).geocoded.filter_by_duration(params[:duration]) if params[:duration].present?
#experiences = policy_scope(Experience).order(price: :desc).geocoded.filter_by_price(params[:price]) if params[:price].present?
However, this only gives me only the records for which the first input value matches but ignores all other values. Additionally, when you are viewing the search results and use the filter again it should apply the filter only for the records it found already.
Any suggestion on how to solve this would be much appreciated!
One way to handle this is to use a virtual model that handles binding parameters to and from the form:
class SearchQuery
include ActiveModel::Model
include ActiveModel::Attributes
attribute :team_size, :integer
attribute :duration
attribute :price
end
You can then setup the form:
<%= form_with(model: (#search_query || SearchQuery.new), url: '/experiences', method: :get) %>
<div>
<%= f.label :team_size %>
<%= f.number_field :team_size %>
</div>
# ..
<% end %>
And then you can just bind the params to the model with ActionController::Parameters#permit just like you would with a normal ActiveRecord model:
class ExperiencesController
before_action :set_search_query, only: :index, if: ->{ params[:search_query].present? }
# ...
def index
#experiences = if #search_query
#search_query.build_scope(policy_scope(Experience))
else
policy_scope(Experience)
end.geocoded
end
private
def set_search_query
#search_query = SearchQuery.new(search_query_params)
end
def search_query_params
params.fetch(:search_query).permit(:team_size, :duration, :price)
end
end
This loopback will make the form stateful just like your normal CRUD forms. We have not actually implemented #build_scope yes so lets do so:
class SearchQuery
include ActiveModel::Model
include ActiveModel::Attributes
attribute :team_size, :integer
attribute :duration
attribute :price
def build_scope(base_scope)
compacted_attributes = attributes.reject { value.nil? || value.empty? }
compacted_attributes.each_with_object(base_scope) do |(k,v), base|
if base.respond_to? "filter_by_#{k}"
# lets you customize the logic with a scope
base.send("filter_by_#{k}", v) # the scope is responsible for ordering
else
# convention over configuration!
base.where(Hash[k,v]).order(Hash[k,:desc])
end
end
end
end
Since this uses convention over configuration you can get rid of those pointless scopes in your model.
In my application when a user visits finances/trends/2014/03 a select query is executed in my trends_controller
#expenses = Expense.select("name, amount, id, created_at").where(:user_id => current_user.id).where(["strftime('%Y', created_at) = ? AND strftime('%m', created_at) = ?", params[:year], params[:month] ])
#expenses_by_month = #expenses.group_by { |expense| expense.created_at.beginning_of_month }
and if the query returns results, the page is rendered, otherwise a redirect occurs. This all seems to work fine.
The problem occurs when I attempt to pass the params[:month] into a link on my index page, and the leading zero in the :month seems to get stripped, so the link will return a path such as finances/trends/2014/3 instead of the required finances/trends/2014/03 for the select statement (because in the db, the created_at value is stored as 2014-03-day, of course).
routes:
get "finances/trends/:year/:month" => "trends#month", :as => :month_trends
index.html.erb:
<% #expenses_by_month.each do |month, expenses| %>
<%= link_to "#{month.strftime('%B')}", month_trends_path(:year => month.year, :month => month.month) %>
<% end %>
I understand that the %m in the select statement should return the month as a padded value, so I'm not sure at all what is causing this.
Try some direct ruby way, if that works. Here is how
"3".rjust(2,"0") #=> 03
"3".ljust(2,"0") #=> 30
month=3
month.to_s.rjust(2,"0") #=> 03
I am trying to search my postgresql db in rails. I followed the Railscasts #111 Advanced Search tutorial and it is working for the name and category of my items column in plain text. However, I want to set a min/max price on my search as well which is where I come into my problem. In my db my price is stored as a string in the format "AU $49.95". Can I convert this into a float on the fly in my scoped search? If so how? If not, what should I do?
Here is the code:
search.rb
class Search < ActiveRecord::Base
attr_accessible :keywords, :catagory, :minimum_price, :maximum_price
def items
#items ||= find_items
end
private
def find_items
scope = Item.scoped({})
scope = scope.scoped :conditions => ["to_tsvector('english', items.name) ## plainto_tsquery(?)", "%#{keywords}%"] unless keywords.blank?
scope = scope.scoped :conditions => ["items.price >= ?", "AU \$#{minimum_price.to_s}"] unless minimum_price.blank?
# scope = scope.scoped :conditions => ["items.price <= ?", "AU \$#{maximum_price.to_s}"] unless maximum_price.blank?
scope = scope.scoped :conditions => ["to_tsvector('english', items.catagory) ## ?", catagory] unless catagory.blank?
scope
end
end
searches_controller.rb
class SearchesController < ApplicationController
def new
#search = Search.new
end
def create
#search = Search.new(params[:search])
if #search.save
redirect_to #search, :notice => "Successfully created search."
else
render :action => 'new'
end
end
def show
#search = Search.find(params[:id])
end
end
Thanks for reading this far!
Use the data type numeric or money for exact numerical calculation without rounding errors - and sorting as a number (not as text).
Converting string literal to numeric should not be a performance problem at all.
This seems like it should be a common problem but I'm having trouble finding an answer. Basically I want to have a form with 10 or so checkboxes which I'm creating with check_box_tag. When the form is submitted I want to generate a query that return all records that match ANY of the checked selections. So, the number of checked selections will vary.
So, for example, if I have
class Book < ActiveRecord::Base
belongs_to :author
end
I want to generate something like
Book.where("author_id = ? or author_id = ?", params[authors[0]], params[authors[1]]) if there are two boxes checked, etc.
Thanks for any insight.
Will this work for you?
Book.where(author_id: [array_of_author_ids])
You need to collect author_ids from params first
I recently had to do something similar, this is how I achieved this. It's pretty clever (at least I think so. :))
I created a query model that serializes the query column (text field) in JSON. I use a form to get the query data from the user with selection fields.
class BookQuery < ActiveRecord::Base
has_many :books
# loop through each foreign key of the Book table and create a hash with empty selection
def self.empty_query
q = {}
Book.column_names.each do |column_name|
next unless column_name.ends_with?("_id")
q.merge column_name => []
end
end
end
I'm using Author as an example below:
<%= form_for #book_query do |f| %>
<% for author in Author.all %>
<%= check_box_tag "book_query[query][author_ids][]", author.id, false%>
<%= author.name %>
<% end %>
<%= f.submit "Save Query" %>
<% end %>
When this form is submitted you ended up with parameters like this:
When the form is submitted it generates this parameter:
Parameters: {"utf8"=>"✓", "authenticity_token"=>"XXXXXXXXXXX", "book_query"=>{"query"=>{"author_ids"=>["2", "3"]}}, "commit"=>"Save Query"}
Now in the BookQuery controller's create action you can just do what create function always does:
def create
#book_query = BookQuery.build(params[:book_query])
if #book_query.save
flash[:success] = "Book query successfully saved."
redirect_to ...
else
flash[:error] = "Failed to save book query."
render :new
end
end
But by default rails serializes the data in hash type:
1.9.3p194 :015 > pp BookQuery.find(9).query
BookQuery Load (0.7ms) SELECT "book_queries".* FROM "book_queries" WHERE "book_queries"."id" = $1 LIMIT 1 [["id", 9]]
"--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess\nauthor_ids:\n- '2'\n- '3'\n"
=> "--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess\nauthor_ids:\n- '2'\n- '3'\n"
In BookQuery model, add the following:
serialize :query, JSON
But rail would change the IDs to string:
1.9.3p194 :018 > query = JSON.parse(BookQuery.find(10).query)
BookQuery Load (0.5ms) SELECT "book_queries".* FROM "book_queries" WHERE "book_queries"."id" = $1 LIMIT 1 [["id", 10]]
=> {"author_ids"=>["2", "3"]}
1.9.3p194 :019 > query["author_ids"]
=> ["2", "3"]
What I did then is override the attribute accessors in BookQuery model:
The below has to be done because the hash returns strings, not ids in integer.
def query=(query)
query.each_pair do |k, v|
if query[k].first.present?
query[k].map!(&:to_i)
else
query.except!(k)
end
end
write_attribute(:query, query)
end
# just want to avoid getting nil query's
def query
read_attribute(:query) || {}
end
To find book with this query, you can simply add this function to your Book model:
def self.find_by_book_query(book_query, options = {})
options[:conditions] = book_query.query
find(:all, options)
end
Now you get a customizable query string based on the model definition Book and everything works like the Rails way. :)
The database is seeded with values in english language and format, e.g., :hourlyrate => 20.90. On first start (language is english by default), the input form displays the content of the field correctly. I can modify and save, no problem.
If I switch to german, the number is displayed correctly as 20,90. If I edit anything on this form, I can not save again, as the validation catches the number as not being valid.
My question is, do I have to perform corrections in my controller before saving, or did I miss some built-in function of Rails?
Relevant parts of the code
Helper:
def my_number_with_precision(value)
if value
# value
number_with_precision(value, :precision => 2)
end
end
Validation:
validates :hourlyrate, :numericality => { :greater_or_equal_than => 0, :message => " is an invalid number or below zero" }
Form:
<div class="input">
<%= f.text_field :hourlyrate, :value => my_number_with_precision(f.object.hourlyrate) %>
</div>
Gemfile
gem 'rails-i18n'
I came up with one of the following solutions - language specific code:
def parse_i18n(value)
if I18n.locale = 'de'
value.gsub(',', '.')
else
value
end
end
def parse_i18n(value)
value.gsub(I18n.t("number.currency.format.unit"),'').
gsub(I18n.t("number.currency.format.delimiter"), '').
gsub(I18n.t("number.currency.format.separator"), '.')
end