Hi --
This is more of an academic question, but I was wondering why the following doesn't work in a view:
<%= @items.each { |@item| render :partial => 'itemrow' } %>
Of course it can be done like this, which works:
<% for @item in @items %> <%= render :partial => 'itemrow' %> <% end %>
But I was curious as to why the first method doesn't work (at least it doesn't work for me). Is it not possible to use blocks in views?
What's happening is this:
<%= ... %> interpolates the string representation of whatever "..." evaluates to. In this case, "..." is a call to @items.each. The each method returns its receiver. So, in effect, what you're doing is:
<%= @items.to_s %>
If you do the "for @item" one, or this:
<% @items each do |@item| %> <%= render :partial => "itemrow" %> <% end %>
then you're interpolating the string representation of the rendering of the partial, zero or more times in succession. You could also do:
<%= @items.map {|@item| render :partial => "itemrow" } %>
which would give you an array of all the rendered results. It's a little less straightforward, though, and depends on representing an array as a string, which is an unnecessary extra step. Mainly I mention it to illustrate the principle at work, which the difference between each and map shows you.
David
