Sorting posts by specific order

Question

I have a custom post type and I want to be able to control the order that the posts are displayed by defining the order in an array, and then checking the posts meta_value against the array to see where it should sit in the order of posts.

Using the code below I can get the dealers who's 'Postcode' is one of the values defined in the $target_postcodes array of the 10 closest postcodes to the current users location.

$posts = get_posts(array(
        'post_type' => 'dealer',
        'meta_key' => 'Postcode',
        'meta_value' => $target_postcodes,
        'post_status' => 'publish'
    ));

Is it possible for me to sort the posts by the order of the values in the 'meta_values' query?

For example, if we use the following post values:

[Name]    [Postcode]
Dealer 1  1234
Dealer 2  2345
Dealer 3  3456
Dealer 4  4567

And then the define the $target_postcodes array as

$target_postcodes = 4567,1234,3456,2345

I would then want the loop to display the dealers in the following order

Dealer 4
Dealer 1
Dealer 3
Dealer 2

Thanks, Brad

Answer 1

You should be able to use a custom query to achieve this. This codex example might be of use.

Answer 2

I ended up querying each postcode separately then compiling the results into the $posts[] array using array_merge. This meant that the final $posts[] array contained all my posts in distance order and I could loop through it normally.

I understand this is a really inneficient way of doing it and would appreciate if anyone could give some feedback/improvements!

The code was similar to below:

/** My array of postcodes, from closest to farthest**/
$postcodes[1111,2222,3333,4444,5555];

/**
 Loop through each postcode and grab all the dealers 
where the postcode matches the one in that loop
**/
foreach($postcodes as $the_postcode){
    $subSet = get_posts(array(
        'post_type' => 'dealer',
        'meta_key' => 'Postcode',
        'meta_value' => $the_postcode,
        'post_status' => 'publish'
    ));
    /**
    Append the new results to the the end of the $posts array
    **/
    $posts = array_merge($posts,$currentSet);
}

/** Display final list of post titles in the order of values defined in $postcodes**/
if($posts)
{ 
    foreach($posts as $post)
    {
    echo the_title().'<br />';
    }
}