Rails 3 - IF a variable contains a part of the URL?

i have a variable like /projects/3/blah blah or /projects/3 or just /projects

What I'd like to do is have an IF statement in Rails like this:

IF urlPath contains /projects proceed

Does Rails / Ruby have a method for that? Also, likely it shouldn't have a false positive for something like /b开发者_开发问答ooks/projects or /authors/mr-projects/ etc...

jquery posting to Rails which them does the above evaluation:

$.ajax({
    url: '/navigations/sidenav',
    //data:{"urlpath":urlpath}, // 
    data: "urlpath=" + urlpath,
    success: function(e){
        $("#sideNav-container").slideDown("slow");
    }
});

In rails you can use starts_with? to do such things:

if params[:urlpath].starts_with? "/projects"
  #...
end

Of course this fails when the hash lookup evaluates to nil. This is where the try method comes in handy:

if params[:urlpath].try(:starts_with?, "/projects")
  #...
end

if params[:urlpath]
   if params[:urlpath].to_s.index('/projects') == 0 
       #...
   end
end

Example:

if params[:urlpath].to_s.match %r{^/projects}
  ...
end

or you could do it with js

'/projects'.match(/^\/projects/)
#=> ["/projects"]
'/books/projects'.match(/^\/projects/)
#=> null

Maybe you wan't to check if some view has been rendered from a specified controller

if params[:controller] == 'projects'
   ...
end