Rails 3 custom validation: Highlighting offending fields - ruby-on-rails-3

I'm writing my first custom rails validation, and would like to tag the offending class with an html "error" class if they return false - I can't quite figure out how to do it. Relevant validation code below - any help appreciated.
(If it makes a difference, I'm using jQuery)
validates_each :shop do |record, attr, value|
shopvar = record.shops.map{ |s| s.email.downcase.strip }
if shopvar.count != shopvar.uniq.count
record.errors.add(attr, 'has the same email address entered more than once')
#record.errors[attr] << "You have entered this shop in the form twice"
end
end

So in your form you'd have something like this for an input field
<%= form.text_field :title %>
Since errors is a hash you could use the "include?" method like so...
errors.include?(:title)
This tells you that there's something wrong with this field. Now all you need to do is style it.
Whack on a ternary operator asi...
<% css_class = errors.include?(:title) ? "highlight_error_class" : "no_problem_class" %>
<%= form.text_field :title, :class => css_class %>
Done.

Related

Learning to Search in Rails

I'm trying to create a search form in my rails application. I've looked up various solutions but they make little sense to me.
I'm getting the following error when I run a search through a form in my rails app. Right now my concern (other than the error) is my instance variable #computers in my index action. I'm pretty sure it's not 'the rails way' to get a search done properly and would love some advice.
Error
undefined method `%' for #<Array:0x5780460>
Parameters after Search
http://localhost:3000/computers?utf8=%E2%9C%93&direction=&sort=&search=bob
Search Form
<%= form_tag computers_path, method: "get" do %>
<%= hidden_field_tag :direction, params[:direction] %>
<%= hidden_field_tag :sort, params[:sort] %>
<%= text_field_tag :search, params[:search] %>
<%= submit_tag "Go", name: nil, class: "btn btn-primary" %>
<% end %>
Call to Method
def index
#computers = Computer.where(school_id: current_user.school_id).search(params[:search]).category(params[:category]).order(sort_column + " " + sort_direction)
end
Method
def Computer.search(search)
if search
search = search.downcase
params = []
values = {}
column_names.each do |c|
params << "#{c} LIKE #{c.to_sym}"
values[c.to_sym] = search
end
params.join (' OR ')
where(params,values)
else
all
end
end
You've got the right idea, but invoking the .join method does not change the object on which it is called, it merely returns a string representation. You need to store the return in a variable, something like this: paramsStr = params.join(' OR '). Then simply pass paramsStr to the where clause.
Ultimately, that is what is causing your unidentified method % for Array .... error; this version of the where method is expecting the first parameter to be a string. Check out this documentation, the part about placeholder conditions.
Hope that helps.

howto globally substitute nil values with a specific character (e.g. "-") in rails views

I guess it's a simple question, but how can I replace nil values in generell in my views.
I want to avoid having something like
<% unless value == nil %>
<%= value %> Ohm
<% else %>
<p>-</p>
<% end %>
Where is the best place to handle this?
I generally put little formatters like this in a helper:
module ResistorsHelper
def format_resistance(resistance)
resistance.nil? ? content_tag(:p, '-') : "#{resistance} Ohm"
end
end

Rails filtering with acts_as_taggable gem

I am working the acts-as-taggable-on gem and have a question about how to filter down search results based on tags users select. Here's an abridged look at my controller:
class PhotosController < ApplicationController
def index
#photos = Photo.where(["created_at > ? AND is_approved = ?", 1.months.ago, true])
#tags = ["Animals", "Architecture", "Cars", "Flowers", "Food/Drink", "General", "Landscape", "Mountains", "Nature"]
end
def search_by_tag(tag)
#photos = Photo.where('tagged_with LIKE ?', tag)
end
end
Photos/index
<% #tags.each do |tag| %>
<%= link_to tag, {:search_by_tag => tag}, :class => "tag" %>
<% end %>
This lists out all of the tags from the hash #tags defined in index, but clicking them doesn't actually filter anything down. Here's a look at what clicking one of those links produces in the log:
Started GET "/photos?search_by_tag=Animals" for 127.0.0.1 at Sun Oct 09 17:11:09 -0400 2011
Processing by PhotosController#index as HTML
Parameters: {"search_by_tag"=>"Animals"}
SQL (0.5ms) SELECT name FROM sqlite_master WHERE type = 'table' AND NOT name = 'sqlite_sequence'
The result I want is for the page to display only Photos that are tagged_with whichever tag was clicked on. I can't quite figure out how to accomplish this.
(Side-question: I can't seem to find a way to list out all of the tags from the tags table that acts-as-taggable-on generated. Doing something like Photo.tagged_with or Photo.tags doesn't work. I am able to see the "tags" table the gem created, and the entries inside of it; I'm just not really clear how to handle that using this gem)
Any thoughts greatly appreciated.
UPDATE
I've updated my code and am a bit closer.
class PhotosController < ApplicationController
def search_by_tag
#photos = Photo.tagged_with(params[:tag_name])
end
photos/index
<% Photo.tag_counts_on(:tags).map(&:name).each do |tag| %>
<%= link_to tag, {:action => 'search_by_tag', :tag_name => tag}, :class => "tag" %>
<% end %>
I believe this is closer, but still working through this...
You have a number of errors in your code:
Your link_to call is actually calling the index action.
Your search_by_tag method is expecting an argument, where it should be using the params hash to access the parameters passed to it in the web request.
tagged_with is a class method added by acts_as_taggable_on, not a field in your table - therefore you can't use it in the where method like you have done.
Finally, to get all the tag names: Photo.tag_counts_on(:tags_or_whatever_you_tagged_on).map(&:name)
Take a look at the acts_as_taggable_on documentation and you'll see examples of how to use tag_counts_on and tagged_with.
As for the Rails things: http://guides.rubyonrails.org/ http://railsforzombies.org/ and/or http://railscasts.com/

Any possible way to set radio_button_tag values by a database set value

I have a radio_button_tag in a form, which holds various values for a persons current availability:
Mike Donnall o Available o Out of office o Vacation
So originally you open the form, and select a value, this then sets the value in the Status table for that Person.
However, there's also functionality to re-open the form and update his present status, perhaps from Vacation to Available.
My question is, is there anyway at all that radio button :checked can be modified to accept a custom method, I have found something in a similar posting, but I want the value foe that radio button to be set to the value in the DB.
My code so far, a stab in the dark perhaps:
View:
<% #people.each do |p| %>
<% #statuses.each do |s| %>
<%= "#{p.name}" %>
<%= "#{s.status_name}" -%><%= radio_button_tag ['person', p.id], ['status',
s.id], checked?(p.id) %>
<% end %>
<% end %>
Helper:
def checked?(person)
#person = person
#status = Status.find_by_sql(['select status_id from statuses where person_id = ?, #person])
if #result
return true
end
As you can see Im a bit lost here, but I understand that the method should return the value of the checkbox that needs to be checked, but Im wondering because its a checked functionality, would it only be limited to being a true or false?
So for a persons.status.id check if its true or false.
It seems from your helper's SQL that you the following relationship setup between People and Statuses:
class Person < ActiveRecord::Base
has_one :status
end
class Status < ActiveRecord::Base
belongs_to :person
end
You can access one given person status like this:
person = Person.first
person_status = person.status
Using that knowledge, your desired view outcome becomes quite simple:
<% #people.each do |p| %>
<p><%= "#{p.name}" -%>
<% #statuses.each do |s| %>
<%= "#{s.status_name}" -%>
<%= radio_button_tag ['person', p.id],
['status', s.id],
(p.status == s) ? true : false %>
<% end %>
<% end %>
You can of course extract the logic to a helper, but that doesn't seem necessary.
On a personal note, this isn't the way I'd present the information to user, it' too heavy on information in one line. I suggest you put the person's name in a p tag, and use a ul tag for the statuses.

Rails HABTM fields_for – check if record with same name already exists

I have a HABTM-relation between the models "Snippets" and "Tags". Currently, when i save a snippet with a few tags, every tag is saved as a new record.
Now i want to check if a tag with the same name already exists and if that´s the case, i don´t want a new record, only an entry in snippets_tags to the existing record.
How can i do this?
snippet.rb:
class Snippet < ActiveRecord::Base
accepts_nested_attributes_for :tags, :allow_destroy => true, :reject_if => lambda { |a| a.values.all?(&:blank?) }
...
end
_snippet.html.erb:
<% f.fields_for :tags do |tag_form| %>
<span class="fields">
<%= tag_form.text_field :name, :class => 'tag' %>
<%= tag_form.hidden_field :_destroy %>
</span>
<% end %>
Ok, i´m impatient… after a while i found a solution that works for me. I don´t know if this is the best way, but i want to show it though.
I had to modify the solution of Ryan Bates Railscast "Auto-Complete Association", which handles a belongs_to-association to get it working with HABTM.
In my snippet-form is a new text field named tag_names, which expects a comma-separated list of tags.
Like Ryan, i use a virtual attribute to get and set the tags. I think the rest is self-explanatory, so here´s the code.
View "_snippet.html.erb"
<div class="float tags">
<%= f.label :tag_names, "Tags" %>
<%= f.text_field :tag_names %>
</div>
Model "snippet.rb":
def tag_names
# Get all related Tags as comma-separated list
tag_list = []
tags.each do |tag|
tag_list << tag.name
end
tag_list.join(', ')
end
def tag_names=(names)
# Delete tag-relations
self.tags.delete_all
# Split comma-separated list
names = names.split(', ')
# Run through each tag
names.each do |name|
tag = Tag.find_by_name(name)
if tag
# If the tag already exists, create only join-model
self.tags << tag
else
# New tag, save it and create join-model
tag = self.tags.new(:name => name)
if tag.save
self.tags << tag
end
end
end
end
This is just the basic code, not very well tested and in need of improvement, but it seemingly works and i´m happy to have a solution!