Difference between respond_to/format and params[:format]

To return non-HTML responses (like XLS spreadsheets), we usually use the

respond_to do |format|
  format.xls do
    # send spreadsheet
  end
end

This is often, but not always the same as checking for params[:format] == :xls, so don't rely on this when e.g. one format checks for authorization and the other doesn't.

params[:format] is only set when a user explicitly puts a .xls at the end of the URL.

The format.xls block also responds when the user's browser requests the application/excel MIME type.

If Internet Explorer runs on a machine with Excel installed on it, this is done automatically.

Thomas Eisenbarth

makandra.de

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Last edit

Over 1 year ago

Michael Leimstädtner

License

Source code in this card is licensed under the MIT License.

There is no real performance difference between "def" and "define_method"

You can define methods using def or define_method. In the real world, there is no performance difference.

define_method is most often used in metaprogramming, like so:

define_method :"#{attribute_name}_for_realsies?" do
  do_things...

Posted by Thomas Eisenbarth to makandra dev (2010-09-08 13:39)

Difference between respond_to/format and params[:format]

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