1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
== Verification ==
Verifications make sure certain criteria are met in order for a controller or action to run. They can specify that a certain key (or several keys in the form of an array) is present in the `params`, `session` or `flash` hashes or that a certain HTTP method was used or that the request was made using XMLHTTPRequest (Ajax). The default action taken when these criteria are not met is to render a 400 Bad Request response, but you can customize this by specifying a redirect URL or rendering something else and you can also add flash messages and HTTP headers to the response. It is described in the link:http://api.rubyonrails.org/classes/ActionController/Verification/ClassMethods.html[API documentation] as "essentially a special kind of before_filter".
Here's an example of using verification to make sure the user supplies a username and a password in order to log in:
[source, ruby]
---------------------------------------
class LoginsController < ApplicationController
verify :params => [:username, :password],
:render => {:action => "new"},
:add_flash => {:error => "Username and password required to log in"}
def create
@user = User.authenticate(params[:username], params[:password])
if @user
flash[:notice] = "You're logged in"
redirect_to root_url
else
render :action => "new"
end
end
end
---------------------------------------
Now the `create` action won't run unless the "username" and "password" parameters are present, and if they're not, an error message will be added to the flash and the `new` action will be rendered. But there's something rather important missing from the verification above: It will be used for *every* action in LoginsController, which is not what we want. You can limit which actions it will be used for with the `:only` and `:except` options just like a filter:
[source, ruby]
---------------------------------------
class LoginsController < ApplicationController
verify :params => [:username, :password],
:render => {:action => "new"},
:add_flash => {:error => "Username and password required to log in"},
:only => :create # Only run this verification for the "create" action
end
---------------------------------------
|
