用数组中的变量替换字符串文本

Question

I am working on a notification system for a game i'm working on.

I decided to store messages as a string with 'variables' set up to be replaced by the data received through an array.

Example of the message:

This notification will display !num1 and also !num2

The array I receive from my query will look like:

[0] => Array
    (
        [notification_id] => 1
        [message_id] => 1
        [user_id] => 3
        [timestamp] => 2013-02-26 09:46:20
        [active] => 1
        [num1] => 11
        [num2] => 23
        [num3] => 
        [message] => This notification will display !num1 and also !num2
    )

What I want to do is replace !num1 and !num2 with the values from the array (11, 23).

message is INNER JOINed in a query from the message_tbl. I suppose the tricky part is num3 which is stored as null.

I am trying to store all notifications for all different types of messages in only 2 tables.

Another example would be :

[0] => Array
    (
        [notification_id] => 1
        [message_id] => 1
        [user_id] => 3
        [timestamp] => 2013-02-26 09:46:20
        [active] => 1
        [num1] => 11
        [num2] => 23
        [num3] => 
        [message] => This notification will display !num1 and also !num2
    )
[1] => Array
    (
        [notification_id] => 2
        [message_id] => 2
        [user_id] => 1
        [timestamp] => 2013-02-26 11:36:20
        [active] => 1
        [num1] => 
        [num2] => 23
        [num3] => stringhere
        [message] => This notification will display !num1 and also !num3
    )

Is there a way in PHP to successfully replace the !num(x) with the correct value in the array?

Answer 1

You can do this with a regular expression and a custom callback, like this:

$array = array( 'num1' => 11, 'num2' => 23, 'message' => 'This notification will display !num1 and also !num2');
$array['message'] = preg_replace_callback( '/!\b(\w+)\b/', function( $match) use( $array) {
    return $array[ $match[1] ];
}, $array['message']);

You can see from this demo that this outputs:

This notification will display 11 and also 23