Optional Partials in the Layout

Rails
1

I want to include a partial in the layout that might not exist. :o)
Here’s an example: Some flows have specific CSS or JavaScript and I’d
like to automatically include those in the HTML (via the
layout), so it would be great to have an optional file in called
_head.rhtml in the views that need it – but not all views.

Does my question make sense?

  • Jeremy
2

Mozmonkey wrote:

I want to include a partial in the layout that might not exist. :o)
Here’s an example: Some flows have specific CSS or JavaScript and I’d
like to automatically include those in the HTML (via the
layout), so it would be great to have an optional file in called
_head.rhtml in the views that need it – but not all views.

One way would be to simply wrap the includes with a conditional:

<% if params[:controller].eql?('certain_controller') %> <%= javascript_include_tag 'some-javascript' %> <% end %> ...

That sort of code can get pretty ugly, so I’d put the whole thing into a
helper. I’m sure someone here has a better way though… :slight_smile:

3

You could always create a partial at app/views/shared/_head.rhtml, and
include it on every page. Inside that partial you could place:

case params[:controller]
when :application
…
end
when :accounts
…
end
end

Same effect as what Daniel said, but at least all your JS/CSS stuff is
kept in one file (and you could be tricky and keep common JS/CSS above
or below the case statement to make sure it’s included on every page,
leaving the blocks inside the case for the specialized JS/CSS).

On Oct 7, 3:24 pm, Daniel W. [email protected]

4

Simpliest way I have found is to do this:-

<%=render :partial=>“side_menu” rescue “”-%>

This way if you have a _side_menu.rhtml file in the controller then it
will use it otherwise display nothing.

5

Thanks for both of your suggestions. With that direction I came up
with a helper that would give me even more control.

Here’s how it works. I have a directory called “shared” directly
under views – this directory is for global partials. I can also have
a partial in the controller view directory with the same name as one
in the shared directory. For example, if I use it like this:

<%= shared :head %>

The helper will start by looking in the controller view directory for
“_head.rhtml” (i.e. views/users/_head.rhtml) and if it’s not there
load up the one in the shared directory (i.e. views/shared/
_head.rhtml). You can also have it include both with the :both
option:

<%= shared :head, :both => true %>

This way “user” pages can include more scripts and CSS in the head
than the default “shared” set. Here’s my code, let me know what you
think:

  #
  # Retreive a partial that can be local to the view or in the shared
directory.
  #
  # = EXAMPLE - For a sidebar
  #    shared/_sidebar.rhtml       - Default global sidebar
  #    search/_sidebar.rhtml        - Used for views under search
  #    welcome/ (no sidebar.rhtml)  - Pages under welcome/ use shared/
_sidebar.rhtml
  #
  #  = OPTIONS
  #    * :both=>true: This includes both the global and local version 
(if
it exists).  The global will always be included first
  #
  def shared(name, options=false)

    content = ""
    name = name.to_s
    file = "_#{name}.rhtml";

    # Render global
    if options && options[:both]
      content = render(:file => "shared/#{file}")
    end

    # Check local
    if File.exist?("#{File.dirname(__FILE__)}/../views/
#{params[:controller]}/#{file}")
      content < name)
    elsif !options || !options[:both]
      content = render(:file => "shared/#{file}")
    end

    return content
  end