I have a form where a user can select a dropdown making it more user friendly. The Letters 'C','W', and 'R' are displayed as cycle, walk, & run
The code is below:
= f.select :kind, [['cycle','C'],['walk','W'],['run','R']]
How would I replace the code above and create a helper to do the same job
maggs
I see no benefit in having a helper that does not have more logic than the used select already handles. But I would move the nested array to the model that has this options. Than you have a reference in your model about valid options.
Assuming the model is named Exercise:
# in model
class Exercise
KINDS = [['cycle','C'],['walk','W'],['run','R']]
validate :kind, :inclusion => { :in => KINDS }
# in view
= f.select :kind, Exercise::KINDS
Related
Having this:
class Event < ActiveRecord::Base
belongs_to :historizable, :polymorphic => true
end
user = User.create!
I can:
Event.create!(:historizable => user)
But I can't:
Event.where(:historizable => user)
# Mysql2::Error: Unknown column 'events.historizable' in 'where clause'
I have to do this instead:
Event.where(:historizable_id => user.id, :historizable_type => user.class.name)
Update
Code that reproduces the issue: https://gist.github.com/fguillen/4732177#file-polymorphic_where_test-rb
This has been implemented in Rails master and will be available in
Rails 4. Thanks.
– #carlosantoniodasilva
I do this:
user.events
This is a proper AR query, you can chain it with other scopes and stuff:
user.events.where(<your event conditions here>)
EDIT: AFAIK the other way around you must specify both fields (makes sense: you could have a user with id 4 and another thing with events, like a Party, also with id 4).
EDIT2: Regarding "Why does create work and where doesn't": create is more highlevel than where, because the former deals with "a complete model", while the latter manages things at the database table level.
ActiveRecord's create (AFAIK) uses a combination of new + update_param somewhere down the line.
update_param uses your model's xxxx= methods for assigning each individual property.
In your example, historizable= is a method built by the belongs_to expression. Since the belongs_to "knows" that it's polymorphic, it can deal with the type and id.
On the other hand, when you pass a hash to the where clause, the parameters there only refer to database fields. Rails provides scopes for "higher level" access:
class Event < ActiveRecord::Base
...
scope :by_historizable, lambda { |h| where(:historizable_id => h.id, :historizable_type => h.class.name) }
end
...
Event.by_historizable(user).where(<your other queries here>)
I've heard that this might change in Rails 4, and where might be more "intelligent". But I have not checked yet.
Try:
Event.joins(:historizable).where(:historizable => {:historizable_type => user})
I hope I am asking this right, so please let me know if I'm way off.
The problem is trying to build a homepage that draws from multiple controllers, to display the nearest locations from multiple controllers, ie. food, businesses, ect.
Right now the individual listings pages have maps drawn from their respective
#json = Controller.all.to_gmaps4rails
How would I do something like :
#json = Controller1 Controller2 .all.to_gmaps4rails
I hope this isnt a noob question and I'm just having a bad day. Thanks guys!
edit 12.5.2011 #seanhill - this is one of the models, the other sections are very close to this format. First off, I wasn't even sure if my homepage requires it's own model, as it doesn't interact with the db at all, more pulling data from controllers that do the work. Thanks for the response Sean!
class Dining < ActiveRecord::Base
validates_uniqueness_of :name, :message => "already exists"
attr_accessible :name, :address, :cuisine, :latitude, :longitude, :about, :facebook, :twitter, :phone, :website
geocoded_by :address
after_validation :geocode, :if => :address_changed?
acts_as_gmappable :process_geocoding => false
def gmaps4rails_address
"#{self.address}"
end
def gmaps4rails_infowindow
"<h3>#{self.name}</h3><br /><h5>#{self.cuisine}</h5>"
end
def self.search(search)
if search
where('name LIKE ?', "%#{search}%")
else
scoped
end
end
end
Try this
holder = Controller1.all
holder << Controller2.all
#json = holder.flatten.map{|h| {lng: h.longitude, lat: h.latitude, class: h.class.to_s}}.to_json
Make sure to change longitude and latitude based on your column names and use js to manipulate the markers based upon class.
As the #Sean Hill said you shouldn't be calling .all on controllers but I think you have a slight misunderstanding of how things are working. Assuming you have a Model called Dining and another called Shop, when you call Dining.all or Shop.all inside class DiningsController < ApplicationController, you are calling .all on either the Dining Model or the Shop Model not on the DiningsController.
The information you display through a controller is only limited by the methods you call in it although it is best practice ensure the main focus of the information displayed is related to the respective controller.
So what you are really trying to do is get the records from multiple models and group them together to display them in a single map.
With that said the answer should read something like this
holder = Dining.all # Takes all Dining records returned as an array and sets them to holder variable
holder << Shop.all # Pushes the Shop records array into the holder with the dining records
holder.flatten!# Next we flatten the array so we only have a single array.
# Then we use the map method to run the given code one time for each instance
# in the holder array to extract the info we need. The results for every instance
# in holder are returned in an array which we then convert to_json.
#json = holder.map{|h| {lng: h.longitude, lat: h.latitude, class: h.class.to_s}}.to_json
#json1 = something.to_gmaps4rails
#json2 = something.to_gmaps4rails
#json = (JSON.parse(#json1) + JSON.parse(#json2)).to_json
I populated the map with my initial data of festivals, and then added the rides to it with javascript with this code,
<% content_for :scripts do %>
<script type="text/javascript">
Gmaps.map.callback = function() {
$.getJSON('/rides_gmap', function(data){
Gmaps.map.addMarkers(data);
});
}
</script>
<%end%>
In the rides controller I had this
def rides_gmap
#rides = Ride.all
#json = #rides.to_gmaps4rails do |ride, marker|
marker.infowindow render_to_string(:partial => "/rides/infowindow", :locals => { :ride => ride})
marker.picture({
'picture' => view_context.image_path("orange-dot.png"),
'width' => 20,
'height' => 20
})
marker.title "#{ride.address}"
marker.json({:ride_id => ride.id, :ride_festivaltype => ride.festival.festivaltype
end
respond_with #json
end
I hope this helps.
I have an Invoice.
Invoice contains LineItems(that belongs to Items).
In the invoice, there is a drop down menu to select line items. I need to add two custom attributes: data-quantity and data-price. (HTML5)
I tried to do it following this article: http://www.redguava.com.au/2011/03/rails-3-select-list-items-with-custom-attributes/ But it doesn't work with nested model attributes.
ApplicationHelper
def options_from_collection_for_select_with_attributes(collection, value_method, text_method, attr_name, attr_field, selected = nil)
options = collection.map do |element|
[element.send(text_method), element.send(value_method), attr_name => element.send(attr_field)]
end
selected, disabled = extract_selected_and_disabled(selected)
select_deselect = {}
select_deselect[:selected] = extract_values_from_collection(collection, value_method, selected)
select_deselect[:disabled] = extract_values_from_collection(collection, value_method, disabled)
options_for_select(options, select_deselect)
end
_line_item_fields.html.erb
Product:
<%= f.select(:item_id, options_from_collection_for_select_with_attributes(#items, :id, :name, 'data-quantity', :quantity), {:prompt => 'Select'}, {:class=>'product'}) %>
I get error: undefined method `quantity' for #Item:0x007f53380eb2
The method in the application helper most probably works well, but the problem is that LineItems belong to Item. LineItems have quantity attribute, but Items don't have a quantity attribute.
As you can see from the error, it's looking at Item, but I it really should reference LineItem.
Found the answer here: ruby on rails f.select options with custom attributes
Look at the answer by Anatortoise House
Works great and there is no need to add a method in the Application Controller.
I'd like to add descriptions to ActiveRecord model fields to serve as basic instructions / examples for each of the fields. Basically model metadata. I can then display these in the UI (next to the fields on a form etc.)
The way I'm planning to do it is simply create a static hashtable inside the model with the field name as the key and description as the value. I.e.
FIELD_DESCRIPTIONS = {
'category' => 'Select the category it should appear within.',
'title' => 'The title should be a short but descriptive summary.',
'description' => 'Please enter a full description.'
}
etc.
Then I would create a a basic form helper that would wrap these explanations inside of a span (initially hidden and shown via jQuery) so they could be instatiated via f.field_description(:title) or something along those lines.
Anyone have any better ideas? I'd like to keep this field metadata in the model since many views could use the same information, and I also think it's nice to have descriptions within the model when you're going back to look at the code (like how DataMapper can be used right within the model to specify fields).
To give you a little more detail on what I've already done (and it works fine) here's the code. I think there has to be a prettier way of expressing these descriptions in the model, so let me know if you have any ideas.
In model:
FIELD_DESCRIPTIONS = {
'category' => 'Select the category it should appear within.',
'title' => 'The title should be a short but descriptive summary.',
'description' => 'Please enter a full description.'
}
def self.describe_field(field)
FIELD_DESCRIPTIONS[field]
end
In application_helper.rb
def field_helper(form, field)
"<span class='field_helper'>#{form.object.class.describe_field(field)}</span>"
end
In view:
<%= field_helper(f, 'title') %>
This will produce the desired output:
<span class='field_helper'>The title should be a short but descriptive summary.</span>
UPDATE:
Ok So this is the final code I'm using based on the accepted answer.
File: /config/initializers/describe_attr.rb
if defined?(ActiveRecord)
# let's us add attribute descriptions to each AR model
class ActiveRecord::Base
def self.describe_attr(*params)
attrs = params.shift
unless attrs.nil?
case attrs
when Hash
##attr_descriptions = attrs
when Symbol
return ##attr_descriptions[attrs]
end
end
##attr_descriptions ||= {}
end
end
end
File: /app/models/project.rb
describe_attr(
:category => 'Select the category the project should appear within.',
:title => 'The title should be a short but descriptive summary of the project.',
:description => 'Describe the project in detail.',
:image => 'Upload an image for the project.'
)
File: /app/helpers/application_helper.rb
# assumes you have a style defined for attr_description
def describe_attr(form, attribute)
"<span class='attr_description'>#{form.object.class.describe_attr(attribute)}</span>"
end
File: /app/views/projects/_form.html.erb
<%= describe_attr(f, :title) %>
The hash is a reasonable simple solution, but if you're on rails 2.2 or higher you might want to try the internationalization api to do this. This would also put you in a good place if you ever wanted to add translations.
Check out the i18n guide for details, but basically you would create a config/locales/en.yml that includes your column names like:
en:
labels:
category: Select the category it should appear within.
Then in your view:
<%= t('labels.category') %>
The namespace is your call of course. Also check out section 4.1.4 for a neat way to separate translations based on your current view template.
If you want to patch ActiveRecord, then you can do something like:
# Add this at the bottom of enviroment.rb
class ActiveRecord::Base
def self.field_description(*params)
attrs = params.shift
unless attrs.nil?
case attrs
when Hash
##field_description = attrs
when Symbol
return ##field_description[attrs]
end
end
##field_description ||= {}
end
end
And inside your model you can add this line like a macro:
class Product < ActiveRecord::Base
field_description :category => 'Select the category it should appear within.',:title => 'The title should be a short but descriptive summary.',:description => 'Please enter a full description.'
end
To get the value
Product.field_description : title
You can mix your solution with the label helper itself:
f.label :title, f.describe(:title)
And in your model:
FIELD_DESCRIPTIONS = {
:category => 'Select the category it should appear within.',
:title => 'The title should be a short but descriptive summary.',
:description => 'Please enter a full description.'
}
def describe(:field)
self.class::FIELD_DESCRIPTIONS[field]
end
Be sure to check out formtastic, which includes support for internationalized (or not) field labels as per matschaffer's answer.
http://github.com/justinfrench/formtastic/
In Ruby on rails, our model includes orders and payments.
There's 1-many relationship between order and payments.
In the orders model we specify:
has_many :payments, :as => :payable
And a payment record has payable_id that is set to order.id.
In a report, I want to select all payments that belong to orders of a given type.
Using:
payments = Payment.find(:all, :conditions => conditions)
and adding 'payable.type="a" ' to the conditions doesn't work.
It seems that ActiveRecord doesn't develop this into a correct join statement (payable_id=order.id and orders.type='a').
I cannot use explicit SQL here, as the condition contains other things that are inserted there earlier in the code.
Thanks,
Raffi Lipkin
Your conditions clause is wrong.
You state that an Order
has_many :payments, :as => :payable
This tells me that a Payment
belongs_to :payable, :polymorphic => true
This means that the payments table has two columns of note: payable_id and payable_type. This also means that Payments can be applied not just to Orders, but also to other models as well (CreditCardBalances, who knows).
If you want to query for payments of a specific type, i.e. belonging to any instance of a particular class, you need to be querying the field payments.payable_type. This works fine:
Payment.find(:all, :conditions => "payable_type = 'Order'")
Here's a gist that shows what I did to test this. The models created are set up just like described above.
Don't forget that you can extract that into named scopes if it's easier:
named_scope :on_orders, :conditions => "payable_type = 'Order'"
Which makes it
Payment.on_orders
Or dynamically:
named_scope :on, lambda { |type| { :conditions => "payable_type = '#{type.to_s}'" } }
Which then makes it
Payment.on(Order) # or Payment.on(CreditCardBalance) or Payment.on("Order")
Try incliding and reference the actual table id name in the condition, rather than the association alias:
find(:include => "payments", :conditions => ["payment.type = ?", "x"]
You mention 'payment type'. If they're fairly static, have you considered using single table inheritance (STI) to subclass your different payment types? Then Rails will do all the magic to filter on type.
E.g.
class CreditCardPayment < Payment
...
end
It doesn't even need to exhibit different behaviour initially; however you'll probably find that it turns out to be really useful to have different data and polymorphic behaviour around payments.