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<h1><span>Controllers</span></h1>
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<h3 id="common-stuff">Common stuff</h3>
<pre><code>redirect_to root_url
redirect_to root_url, notice: "Good."
</code></pre>
<h3 id="special-hashes">Special hashes</h3>
<pre><code>session[:user_id] = nil
flash[:notice] = "Hello" # Gets flushed on next request
flash.keep # Persist flash values
flash.now[:error] = "Boo" # Available on the same request
cookies[:hello] = "Hi"
params[:page]
# params is a combination of:
query_parameters
path_parameters
request_parameters
</code></pre>
<h3 id="respond_to">respond_to</h3>
<pre><code>respond_to do |format|
format.html
format.xml { render xml: @users }
format.json { render json: @users }
format.js # Will be executed by the browser
end
</code></pre>
<h3 id="default_url_options">default_url_options</h3>
<pre><code># The options parameter is the hash passed in to 'url_for'
def default_url_options(options)
{:locale =&gt; I18n.locale}
end
</code></pre>
<h3 id="filters">Filters</h3>
<pre><code># Filter with callbacks
before_filter :authenticate
before_filter :authenticate, except: [:login]
before_filter :authenticate, only: [:login]
def authenticate
redirect_to login_url unless controller.logged_in?
end
# Filter with inline
before_filter do |controller|
redirect_to login_url unless controller.logged_in?
end
# Filter with external classes
before_filter LoginFilter
class LoginFilter
def self.filter(controller) ...; end
end
# Filter exceptions
skip_before_filter :require_login, only: [:new, :create]
# Before/after filters
around_filter :wrap_in_transaction
def wrap_in_transaction(&amp;blk)
ActiveRecord::Base.transaction { yield }
end
</code></pre>
<h3 id="http-basic-authentication">HTTP basic authentication</h3>
<pre><code>before_filter :authenticate
# Basic authentication:
def authenticate
authenticate_or_request_with_http_basic { |u, p|
u == "root" &amp;&amp; p == "alpine"
}
end
# ...or digest (hashed) authentication:
# uses the ha1 hash (username:realm:password)
def authenticate_by_digest
realm = "Secret3000"
users = {
"rsc" =&gt; Digest::MD5.hexdigest("rsc:#{realm}:passwordhere")
}
authenticate_or_request_with_http_digest(realm) { |user|
users[user]
}
end
# For integration tests
def test_access
auth = ActionController::HttpAuthentication::Basic.encode_credentials(user, pass)
get "/notes/1.xml", nil, 'HTTP_AUTHORIZATION' =&gt; auth
end
# Token auth
is_logged_in = authenticate_with_http_token do |token, options|
token == our_secret_token
end
request_http_token_authentication unless is_logged_in
</code></pre>
<h3 id="requestresponse">Request/response</h3>
<pre><code>request.host #=&gt; "www.example.com"
request.domain #=&gt; "www.example.com"
request.domain(n=2) #=&gt; "example.com"
request.port #=&gt; 80
request.protocol #=&gt; "http://"
request.query_string #=&gt; "q=duck+tales"
request.url #=&gt; "http://www.example.com/search?q=duck+tales"
request.fullpath #=&gt; "/search?q=duck+tales"
request.headers # Returns a hash
request.format #=&gt; "text/html"
request.remote_ip #=&gt; "203.167.220.220"
request.local? #=&gt; true (if localhost/127.0.0.1)
request.xhr?
request.method #=&gt; "POST"
request.method_symbol #=&gt; :post
request.get?
request.post?
request.put?
request.delete?
request.head?
</code></pre>
<h3 id="response">response</h3>
<pre><code>response.body
response.status #=&gt; 404
response.location # Redirect location
response.content_type
response.charset
response.headers
response.headers["Content-Type"] = "application/pdf"
</code></pre>
<h3 id="streaming">Streaming</h3>
<pre><code>send_data pdfdata, filename: "foo.pdf", type: "application/pdf"
send_file Rails.root.join('public','filename.txt') [filename: '..', type: '..']
</code></pre>
<h3 id="references">References</h3>
<ul>
<li><a href="http://guides.rubyonrails.org/action_controller_overview.html">Guide</a></li>
<li><a href="http://api.rubyonrails.org/classes/ActionController/HttpAuthentication/Basic.html">HttpAuthentication::Basic</a></li>
<li><a href="http://api.rubyonrails.org/classes/ActionController/HttpAuthentication/Token.html">HttpAuthentication::Token</a></li>
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