render partial :object vs :locals

Question

<%= render :partial => 'partial/path', :locals => {:xyz => 'abc'} %> 

vs

<%= render :partial => 'partial/path', :object => @some_object %> 

I think the first one make a local variable named xyz available in the partial and the second one makes a local variable named object available in the partial. So what is the difference? (Besides locals allows more than one variable)

Answer 1

The second form

render :partial => 'account', :object => @some_account 

will make sure the account variable in the partial will be set to @some_account. You can rename the variable using the :as option.

The biggest advantage of the :locals is that

• you have very clear control over the objects and names
• you can assign more than 1 variable

So you could do something like

render partial => 'some_view', :locals => { :user => account.user, :details => some_details_we_retrieved } 

making a clear seperation possible when needed.

The disadvantage of the :locals approach is that it is more verbose, and sometimes a simple

render :partial => 'account' 

is identical to

render :partial => 'account', :locals => {:account => @account } 

So use the one which suits you the best (or where it suits the best).