my suggestion for using custom tags in the newsletter text – not a help request

hello.

I was asked to import several hundreds of users in a wordpress site and send them their username and password to access an otherwise restricted page, so I thought to use the Newsletter plugin and see if I could modify it to use some custom {tags} in the newsletter text.

for reasons too long to explain here I was asked not to let future users just use the wordpress functionalities that permit them to register themselves, choosing their username and pw etc., and I was also asked not to expose them the wordpress backend interface (I did this with the plugins “Clean Login” and “Custom Control”).

I was given a csv files with the users data (name, surname, email, password etc.). I imported them as wordpress users with the “Import and export users and customers” plugin – everything smooth, then I imported them as newsletter_users with the add-on Advanced Import, everything smooth again. I just added an Extra Field for the initially assigned password (users can change it later on).

I found where, in the code of Newsletter plugin, the tags search and replace was made: the function replace() at row 2005 of the includes/module.php file.

just before the return $text; row I added this:

<code>
if ( strpos ( $text, '{assigned_password}' ) !== false ) {
  $assigned_password = my_function_to_extract_the_assigned_password( $user ) ;
  $text = str_replace ( '{assigned_password}', $assigned_password, $text ) ;
}
</code>

my_function_for_assigned_password() is a function I placed in the function.php file of the child theme to search for the $user assigned password in the users csv file, transformed in an array, and return it. something like that:

<code>
my_function_to_extract_the_assigned_password( $user ) {

    $csv = "namesurname;name.surname@example.com;assigned_strong_pw;Name Surname;Name;Surname;
...";

// note: no spaces between ""

    $arr_users = array();
    $arr_csv = explode ( "\n", $csv );
    
    foreach ($arr_csv as $row) {
    	$arr_row = explode(';', $row);
        $arr_users[ $arr_row[0] ] = array(
            'username'   => $arr_row[0],
            'email'      => $arr_row[1],
            'password'   => $arr_row[2],
            'name'       => $arr_row[3],
            'first_name' => $arr_row[4],
            'last_name'  => $arr_row[5],
            );
    }

    $username = strtolower($user->name) . strtolower($user->surname) ;
    $password = $arr_users[$username]['password']; 

    return $password;

}
</code>

ok, I know there are a lot of redundancies, and that I would read the entire array each time the function is called, that is, each time the newsletter text is created for the specific user, and that I could have used specific php functions to read a csv file in an array, but I preferred not to leave – even if for a short time – a file with such information in the filesystem, and placing its content in a .php file seemed a good idea.

in this case I just needed to return one string, $password, but returning an array would allow to use more custom tags.

the code to add to the replace() function could then be something like:

<code>
if ( function_exists ( developer_function_to_extract_custom_tags ) ) {
  $arr_my_custom_tags = developer_function_to_extract_custom_tags( $user )
  if ( is_array ( $arr_my_custom_tags ) ) {
    foreach ( $arr_my_custom_tags as $key_custom_tag => $value_custom_tag ) {
      if ( strpos ( $text, '{' . $key_custom_tag . '}' ) !== false ) {
        $text = str_replace ( '{' . $key_custom_tag . '}' , $value_custom_tag, $text ) ;
      }
    }
  }
}

you just would have to tell the developer that the function MUST be called that way, or another of your choice.

or, maybe better, you could set a custom hook just before the return $text; row:

<code>
  ...
  apply_filters ( 'newsletter_replace_custom_tags', $text, $user ) ;
  return $text;
}

and let the developer to hook in his own tag replacement function.