WordPress: how to return meta with query_posts?

I'm doing an AJAX request using admin-ajax.php whereby I filter posts based on which check-box is checked. It's working great, although I'm struggling to find a way to return the meta details of each post.

I'm just using query_posts to get my data as below:

function ajax_get_latest_posts($tax){

$args= array(
'post_type'=>'course',

'tax_query' => array(
array(
'taxonomy' => 'subject',
'field' => 'slug',
'terms' => $tax
)
)

);

$posts=query_posts( $args);


return $posts;
}

How would I modify this to also return meta data? I know I can filter the posts by meta data using meta_query, but I just want to display the data in my posts.

EDIT:

Besides the solution outlined bellow, if you're using WordPress >= 3.5(as you should be :) ), you can simply make use of the magic methods of the WP_Post object.

Basically the WP_Post object(which is what the posts array from pretty much every query result that comes from WP_Query consists of) is using PHP's `__get()` and `__isset()` magic methods. These methods allow you to use properties of an object that are not defined in the object itself.

Here's an example.

foreach ( $posts as $key => $post ) {
// This:
echo $post->key1;
// is the same as this:
echo get_post_meta( $post->ID, 'key1', true );
}

If you make a `print_r( $post )` or `var_dump( $post )`, you will not see the "key1" property of the `$post` object. But the function [__get()](

[To see links please register here]

) allows you to access that property.

===========================================================

You have two general options in my opinion - loop through the posts and get the data that you need, like so(this code will go right after `$posts = query_posts( $args );`):

foreach ( $posts as $key => $post ) {
$posts[ $key ]->key1 = get_post_meta( $post->ID, 'key1', true );
$posts[ $key ]->key2 = get_post_meta( $post->ID, 'key2', true );
}

Or hook to the `the_posts` filter hook and do the same thing there(more work, but if you have multiple functions that need to add that data to each post - it might be easier). This code would go to your functions.php or your plugin's files(if you're making a plugin):

function my_the_posts_filter( $posts ) {
foreach ( $posts as $key => $post ) {
$posts[ $key ]->key1 = get_post_meta( $post->ID, 'key1', true );
$posts[ $key ]->key2 = get_post_meta( $post->ID, 'key2', true );
}

return $posts;
}

And then you would change your

$posts=query_posts( $args);

line to this:

add_filter( 'the_posts', 'my_the_posts_filter', 10 );

$posts = query_posts( $args );

remove_filter( 'the_posts', 'my_the_posts_filter', 10 );

Considering the fact that this would happen inside of an AJAX request, you can technically get rid of the `remove_filter()` call, but it's good to have it just in case you're going to make any other post queries in your code.