How can validate params in the view? - ruby-on-rails

Question

Here is the table:
|policies|
|id| |name| |date|
1 ABC 2013-01-01
2 DEF 2013-01-21
Here is the controller:
class PolicyController < ApplicationController
def index
#policies = Policy.find(:all,:conditions=>['date BETWEEN ? AND ?',params[cam],params[:cam2] ])
end
end
Here is the model:
class Policy < ActiveRecord::Base
end
Here is the view:
<% CalendarDateSelect.format=(:hyphen_ampm )%>
<% calendar_date_select_style "silver" %>
<% translation_calendar %>
<% form_tag :controller=>"policy",:action=>"index" do %>
From: <%= calendar_date_select_tag "cam", params[:cam] %>
To: <%= calendar_date_select_tag "cam2",params[:cam2] %>
<%= submit_tag "Search", :name => nil %></p>
<% end %>
<% #policies.each |p| do %>
<%= p.date %>
<% end %>
How can block the SEARCH button until my 2 calendar text have values?
I tried this:
class Policy < ActiveRecord::Base
validates_presence_of :cam
end
Please somebody can help me please or maybe a javascript?
I will appreciate all kind of help.
Here is what friends told me:
named_scope :by_calendar_date,lambda { |cam1, cam2| } {
if cam1.nil? && cam2.nil?
scoped
elsif cam1.nil?
where("date < ?",cam2)
elsif cam2.nil?
where("date > ?", cam1)
else
where("date BETWEEN ? AND ?",cam1,cam2)
end
}
#this would perform the same functionality so both are not needed but just for edification
def self.by_calendar_date(cam1,cam2)
if cam1.nil? && cam2.nil?
scoped
elsif cam1.nil?
where("date < ?",cam2)
elsif cam2.nil?
where("date > ?", cam1)
else
where("date BETWEEN ? AND ?",cam1,cam2)
end
end

Answer 1

Since this is a search feature you do not need to validate in my opinion you could just do this
class Policy < ActiveRecord::Base
named_scope :by_calendar_date,lambda{|cam1,cam2|
if cam1.nil? && cam2.nil?
{:conditions => {}}
elsif cam1.nil?
{:conditions => ["date < ?",cam2]}
elsif cam2.nil?
{:conditions => ["date > ?", cam1]}
else
{:conditions => ["date >= ? AND date <= ?",cam1,cam2]}
end
}
end
call with
def index
#policies = Policy.by_calendar_date(params[:cam1],params[:cam2])
end
This way the user can set either param individually or none at all

Answer 2

Check out this fiddle... http://jsfiddle.net/qKG5F/641/
HTML
// note the change... I set the disabled property right away
<input type="submit" id="register" value="Register" disabled="disabled" />
JavaScript
(function() {
$('form > input').keyup(function() {
var empty = false;
$('form > input').each(function() {
if ($(this).val() == '') {
empty = true;
}
});
if (empty) {
$('#register').attr('disabled', 'disabled'); // updated according to http://stackoverflow.com/questions/7637790/how-to-remove-disabled-attribute-with-jquery-ie
} else {
$('#register').removeAttr('disabled'); // updated according to http://stackoverflow.com/questions/7637790/how-to-remove-disabled-attribute-with-jquery-ie
}
});
})()
The nice thing about this is that it doesn't matter how many input fields you have in your form, it will always keep the button disabled if there is at least 1 that is empty. It also checks emptiness on the .keyup() which I think makes it more convenient for usability.
I hope this helps.