1 files changed, 89 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/core_ext/object/to_query.rb b/activesupport/lib/active_support/core_ext/object/to_query.rb
new file mode 100644
index 0000000000..bac6ff9c97
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/to_query.rb
@@ -0,0 +1,89 @@
+# frozen_string_literal: true
+
+require "cgi"
+
+class Object
+  # Alias of <tt>to_s</tt>.
+  def to_param
+    to_s
+  end
+
+  # Converts an object into a string suitable for use as a URL query string,
+  # using the given <tt>key</tt> as the param name.
+  def to_query(key)
+    "#{CGI.escape(key.to_param)}=#{CGI.escape(to_param.to_s)}"
+  end
+end
+
+class NilClass
+  # Returns +self+.
+  def to_param
+    self
+  end
+end
+
+class TrueClass
+  # Returns +self+.
+  def to_param
+    self
+  end
+end
+
+class FalseClass
+  # Returns +self+.
+  def to_param
+    self
+  end
+end
+
+class Array
+  # Calls <tt>to_param</tt> on all its elements and joins the result with
+  # slashes. This is used by <tt>url_for</tt> in Action Pack.
+  def to_param
+    collect(&:to_param).join "/"
+  end
+
+  # Converts an array into a string suitable for use as a URL query string,
+  # using the given +key+ as the param name.
+  #
+  #   ['Rails', 'coding'].to_query('hobbies') # => "hobbies%5B%5D=Rails&hobbies%5B%5D=coding"
+  def to_query(key)
+    prefix = "#{key}[]"
+
+    if empty?
+      nil.to_query(prefix)
+    else
+      collect { |value| value.to_query(prefix) }.join "&"
+    end
+  end
+end
+
+class Hash
+  # Returns a string representation of the receiver suitable for use as a URL
+  # query string:
+  #
+  #   {name: 'David', nationality: 'Danish'}.to_query
+  #   # => "name=David&nationality=Danish"
+  #
+  # An optional namespace can be passed to enclose key names:
+  #
+  #   {name: 'David', nationality: 'Danish'}.to_query('user')
+  #   # => "user%5Bname%5D=David&user%5Bnationality%5D=Danish"
+  #
+  # The string pairs "key=value" that conform the query string
+  # are sorted lexicographically in ascending order.
+  #
+  # This method is also aliased as +to_param+.
+  def to_query(namespace = nil)
+    query = collect do |key, value|
+      unless (value.is_a?(Hash) || value.is_a?(Array)) && value.empty?
+        value.to_query(namespace ? "#{namespace}[#{key}]" : key)
+      end
+    end.compact
+
+    query.sort! unless namespace.to_s.include?("[]")
+    query.join("&")
+  end
+
+  alias_method :to_param, :to_query
+end