Add Link To The Current Page With Query Params as a Rails til

rails/link-to-the-current-page-with-query-params.md

@@ -0,0 +1,36 @@
+# Link To The Current Page With Query Params
+
+The `link_to` method is an ActionView helper for generating an `a` tag within a
+Rails view. There are two arguments that tend to comprise this method: the link
+text and a path helper.
+
+```ruby
+<%= link_to 'Home', root_path %>
+```
+
+The `link_to` method can be used to generate a link to the current page with
+query params. You can do this be providing a hash instead of a path helper as
+the second argument.
+
+```ruby
+<%= link_to "All", {filter: 'all'} %>
+<%= link_to "New", {filter: 'new'} %>
+<%= link_to "Posted", {filter: 'posted'} %>
+```
+
+The hash can contain one or more key-value pairs which will be turned into
+query params and appended to the end of the current base path.
+
+If these are part of the `posts` index page, then they will render as:
+
+```html
+<a href="/posts?filter=all">All</a>
+<a href="/posts?filter=new">New</a>
+<a href="/posts?filter=posted">Posted</a>
+```
+
+This is a great way to create links for a Rails action that presents different
+data based on query params. Often this is an index page where filtering is
+needed.
+
+[source](https://gorails.com/episodes/rails-link-to-current-page-with-params)