How do I decide between theme('node', $node) and drupal_render($node->content) for programmatic $node output

Question

Given a $node, I'm trying to decide between the following two ways of outputting that $node.

either

$output = theme('node', $node);

or

node_build_content($node);
$output = drupal_render($node->content);

They both seem to give similar results, but is there something I should consider before I choose one way over the other?

Answer 1

Your output is similar if there are no other modules and themes altering the output via the theme layer.

But! If you bypass the theme layer, you'll probably start experiencing unexpected behaviour when you install modules or themes and change config settings that use the theme layer to alter the node's output.

In short, by bypassing the theme layer, you're building error into your application. These error are likely to occur after you hand your application over to someone (a client perhaps) who starts changing settings in admin/

See the decorator pattern if you're interested. Drupal uses this extensively.

http://en.wikipedia.org/wiki/Decorator_pattern

Answer 2

Well, sortof.

What you really want is

$output = node_view($node);

if you just call node_build_content, and then call theme('node', $node), hook_nodeapi('alter') is never called, nor is hook_link().

So if any module is expecting to alter the built node, it wont get a chance to, and if there is supposed to be links on it they wont be there either.

Additionally you can call $output = node_view($node, FALSE, FALSE, FALSE); which gives you the node without the links.

See the documentation for node_view().

Answer 3

If you look into the source of drupal_render(), it actually calls theme() itself as well (provided a #theme override is provided).

Answer 4

In Drupal 7, you should do :

$elements = node_view($node, 'teaser');
$rendered_node = drupal_render($elements);

Answer 5

The solution that worked here was a combination of both of these techniques. Just using theme('node', $node); doesn't seem to work without the help of node_build_content($node);.

Here is the result of an example only using theme('node', $node);.

But if we first do node_build_content($node); prior to handling the $node to the theme function, you can see that the form button is also rendered.

Therefore, the real solution is:

node_build_content($node);
$output = theme('node', $node);

Answer 6

First is recommended, as it is passed via the theme layer.