Recent notes
RSS feedSetting child_index while using nested attributes mass assignment
When using nested attributes mass assignment sometimes you will want to add new records with javascript. You can do it with pure javascript, but if HTML is long your javascript will be long and messy and it will not be DRY as probably you already have a partial for it.
So to add a partial dynamically you can do something like that (notice string “index_to_replace_with_js”):
link_to_function
def add_object_link(name, form, object, partial, where) options = {:parent => true}.merge(options) html = render(:partial => partial, :locals => { :form => form}, :object => object) link_to_function name, %{ var new_object_id = new Date().getTime() ; var html = jQuery(#{js html}.replace(/index_to_replace_with_js/g, new_object_id)).hide(); html.appendTo(jQuery("#{where}")).slideDown('slow'); } end
js method in one of helpers (from minus mor plugin)
def js(data) if data.respond_to? :to_json data.to_json else data.inspect.to_json end end
This method will generate link adding generated partial to html.
The thing that is not mentioned in docs is how to set child_index. You must add it as an argument in hash.
Example of partial
<% form.fields_for :tasks, task, :child_index => (task.new_record? ? "index_to_replace_with_js" : nil) do |tasks_form| %> <% tasks_form.text_field :name %> <% end %>
Using add_object_link
<% form_for :project do |form| %> <div id="tasks"> <%# displaying existing tasks %> </div> <%= add_object_link("New task, form, Task.new, "task", "#tasks") %> <% end %>
Thanks to child_index after insertion it will change indexes to current time in miliseconds so added tasks will have different names and ids.
Translations of label method
The label method won’t use your translated attribute names - which seems like big disadvantage of this method.
For a quick workaround, try using this in a helper:
def label(object_name, method, text = nil, options = {}) text ||= object_name.classify.constantize.human_attribute_name(method.to_s) ActionView::Helpers::InstanceTag.new(object_name, method, self, options.delete(:object)).to_label_tag(text, options) end
I didn’t properly test this, but it seems to work.
Superclass of OrderedHash
Note that in Rails 2.3, OrderedHash changed from being a subclass of Array to a subclass of Hash. This is contrary to what the documentation says above.
HTML entities in options
Unfortunately everything is escaped with ERB::Util#html_escape. Your only option is either manually construct options or compeletely overwrite this method.
Array clustering
Sometimes you don’t want to mangle sequence of an array and just want to group adjacent values. Here’s a nice method to do so (drop it in your initializers directory or something):
module Enumerable # clumps adjacent elements together # >> [2,2,2,3,3,4,2,2,1].cluster{|x| x} # => [[2, 2, 2], [3, 3], [4], [2, 2], [1]] def cluster cluster = [] each do |element| if cluster.last && yield(cluster.last.last) == yield(element) cluster.last << element else cluster << [element] end end cluster end end
Similarly you can do the clustering on more complex items. For instance you want to cluster Documents on creation date and their type:
Document.all.cluster{|document| [document.created_on, document.type]}
Take care when writing regex
When you want to validate a field for a continuous string you’d probably write something like this (if it’s really early in the morning and you didn’t have your coffee yet):
validates_format_of :something => /\w/
At the first sight it looks like it’s working because something = “blahblahblah” is valid. However, so is this: something = “blah meh 55”. It’s just that your regex matched a substring of the value and not the whole thing. The proper regex you’re looking for is actually:
validates_format_of :something => /^\w$/
Assets hosts
You can also setup assets hosts in enviroments:
config.action_controller.asset_host = "http://your-assets-server.com"
The docs are in AR::Base
The docs you’re looking for are in ActiveRecord::Base
Patch looks good.
I assume commenting right below the ticket is the “+1” action? :) Thanks for the reply and patch efforts!
Exension module patch
I’d say its just an oversight.
If you’d like to see all associations get equal support for extension modules take a look at this patch and give it a +1.
Why such inconsistency on 'extend' design?
Thanks for the great note! Finally… it took me quite some time to find this page and track down why there is such inconsistency between belongs_to and, say, has_many, proxy extension design. Do you (or anyone knowledgeable here) know the reason behind such design inconsistency? It’s quite annoying (and quite abstraction- and documentation-defeating) that one has to look this deep into the source code to see what’s going on.… Thanks!
Returns the element, not block result
Enumerable#find will always return the element that is found, not the result of the block provided.
Ordering of format blocks is important
The order in which your format blocks appear, like:
format.html { } format.js { }
are used to infer priority in cases where the appropriate format is ambiguous.
Deprecated
This method is now at ActiveSupport::CoreExtensions::Module#alias_method_chain
Reconfiguring the Rails cleaner
The Rails cleaner is available from the top-level Rails class:
Rails.backtrace_cleaner
Sorting Hashes with Symbol Keys
To sort a hash with symbol keys, use Enumerable#sort_by:
h = { :a => 20, :b => 30, :c => 10 } h.sort # => NoMethodError: undefined method `<=>' for :a:Symbol h.sort_by { |k,v| k.to_s } # => [[:a, 20], [:b, 30], [:c, 10]]
Override fieldWithErrors markup in Rails > v2
The code posted by @hosiawak will still work in recent versions of Rails, but maybe a more current, idiomatic way to do it is to stick this inside the Rails::Initializer block in environment.rb (obviously you’ll also need to restart your server to pick up the config change):
config.action_view.field_error_proc = Proc.new {|html_tag, instance| %(<span class="fieldWithErrors">#{html_tag}</span>)}
Input for trigonometric functions must be radians
You must use radians to have the right result. For example to compute the sin of 125 degrees use:
Math.sin(125*Math::PI/180)
Hour with/without preceding zero
One gotcha is the difference between the hour in 12 hour time with and without a preceding zero. In some fonts they look the same.
With preceding zero (capital I)
Time.now.strftime("%I:%M") # => 05:21
Without preceding zero (lowercase L)
Time.now.strftime("%l:%M") # => 5:21
Hour with/without preceding zero
One gotcha is the difference between the hour in 12 hour time with and without a preceding zero. In some fonts they look the same.
With preceding zero (capital I)
Time.now.strftime("%I:%M") # => 05:21
Without preceding zero (lowercase L)
Time.now.strftime("%l:%M") # => 5:21
Usage
Here’s how to use it, just so it’s perfectly clear:
skip_before_filter :method_to_skip, :only => [:method_name]
Deprecated - replacement method
The description rightly lists this as deprecated, but using it will still work atm, as it seems to have moved to ActiveSupport::CoreExtensions::Module instead.
So your code should still work.
multiple filter example
actually you can have it even shorter with:
before_filter :authorize, :set_locale, :except => :login
Gotcha with method calls inside select loop
Keep in mind that any methods you call on the object in the select loop will be strung together when the Javascript is rendered. For example:
page.select(".shipping_type_fee").each do |td| td.down("span").update("--").show td.down("img").hide end
will be rendered as:
$$('.shipping_type_fee').each(function(value, index) { value.down("span").update("--").show().down("img").hide(); });
This is probably not what you want!
No documentation here…
…but you’re probably looking for ActionController::RequestForgeryProtection::ClassMethods
usage helper with block
helper example
def my_helper(&block) inner = capture(&block) out = "<somehtml>#{inner}</somehtml>" block_called_from_erb?(block) ? concat(out) : out end
view example
<% my_helper do %> sometext <% end %>
output
<somehtml>sometext</somehtml>