Difference between Render and Render Partial and Yield
About render , render :partial and yield
render :template and render :partial are two files in rails..
render :template are mostly created according to an action with syntax demo.html.erb
render :partial are reuseable and called from different views , are shared among many pages in application and syntax is _demo.html.erb
yield and render..
Yield is a way to call a block of code with its output but render will include a partial page template where it is called. In rails yield is mostly used in layout whereas render is used in actions or their templates
render
& render partial:
render 'some_view'
is a shorthand forrender partial: 'some_view'
.render file: 'view'
will look for a fileview.html.erb
and NOT_view.html.erb
(.erb
or any other renderer you use)render
will not accept additional local variables for the partial, you need to userender partial:
as following for that:render partial: 'some/path/to/my/partial', locals: { custom_var: 'Hello' }
(http://guides.rubyonrails.org/layouts_and_rendering.html#passing-local-variables)
yield
& content_for
yield
is typically used in layouts. It tells Rails to put the content for this block at that place in the layout.- When you do
yield :something
associated withcontent_for :something
, you can pass a block of code (view) to display where theyield :something
is placed (see example below).
A small example about yield:
In your layout:
<html>
<head>
<%= yield :html_head %>
</head>
<body>
<div id="sidebar">
<%= yield :sidebar %>
</div>
</body>
In one of your view:
<% content_for :sidebar do %>
This content will show up in the sidebar section
<% end %>
<% content_for :html_head do %>
<script type="text/javascript">
console.log("Hello World!");
</script>
<% end %>
This will produce the following HTML:
<html>
<head>
<script type="text/javascript">
console.log("Hello World!");
</script>
</head>
<body>
<div id="sidebar">
This content will show up in the sidebar section
</div>
</body>
Posts that might help:
- Embedded Ruby -- Render vs. Yield?
- Render @object and locals vs render :partial
- Rails: about yield
Links to documentation & guides:
- http://guides.rubyonrails.org/layouts_and_rendering.html#passing-local-variables
- http://apidock.com/rails/ActionView/Helpers/CaptureHelper/content_for
- http://apidock.com/rails/ActionController/Base/render