Rails Migration: Remove constraint
I have a table in a Rails application which (in schema.rb) looks like: create_table "users", :force => true do |t| t.string "name", :null=>false t.string "address", :null=>false end I would like to write a rails migration to allow nulls for the address field. i.e. after the migration the table looks like this: create_table "users", :force => true do |t| t.string "name", :null=>false t.string "addr
ActiveRecord: How to get all attributes of a model that can be mass-assigned?
I would like to have a list of all attribute names that can be mass assigned. I need this for a custom form builder that will not add input fields by default that cannot be mass assigned. For example if I have the following model: class Post < ActiveRecord::Base attr_protected :account belongs_to :author validates_presence_of :title, :author end I would like to have as a result [:author, :title].
Safe integer parsing in Ruby
I have a string, say '123', and I want to convert it to the integer 123. I know you can simply do some_string.to_i, but that converts 'lolipops' to 0, which is not the effect I have in mind. I want it to blow up in my face when I try to convert something invalid, with a nice and painful Exception. Otherwise, I can't distinguish between a valid 0 and something that just isn't a number at all. EDIT:
How do I implement Common Lisp's mapcar in Ruby?
I want to implement Lisp's mapcar in Ruby. Wishful syntax: mul = -> (*args) { args.reduce(:*) } mapcar(mul, [1,2,3], [4,5], [6]) would yield [24, nil, nil]. Here is the solution I could think of: arrs[0].zip(arrs[1], arrs[2]) => [[1, 4, 6], [2, 5, nil], [3, nil, nil]] Then I could: [[1, 4, 6], [2, 5, nil], [3, nil, nil]].map do |e| e.reduce(&mul) unless e.include?(nil) end => [24, nil, nil] But I'
Passing parameters to partial view
I have a view that displays multiple images and those images' associated tags. I decided to use a partial view for each image and its tags, but I am having trouble passing in the image object into the partial view. Here is the main view's relevant code: <table> <% @images.each do |i| %> <tr> <%= render :partial => :image_tag, :image => i %> </tr> <% end %> </table> Here is the partial view's relev
ie8 Sortable not working
I have a pretty complex setup of nested sortables I have created a jsfiddle at http://jsfiddle.net/mwagner72/Phbzc/ The problem is when using ie8, click the rearrange button, then use the blue box as drag handles. as you can see it is not working. Works fine in other browsers. I see a realated ticket ( I believe it is related) on the jquery site here: http://bugs.jqueryui.com/ticket/5197 But I am
Jquery will not load because it can't be found
My html page don't works because my script is not loading. The script I'm using is as follows: <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script> This is the error: Failed to load resource: net::ERR_FILE_NOT_FOUND file://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js Can you see the problem? I just copied the scripts src from google hosted libraries.
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