Building a custom login process

if ( is_user_logged_in() ) {

    // The user is logged in.
    
    /**
     * You could potentially use wpmem_is_blocked() in here to build additional 
     * logic for blocked vs unblocked content.  You could also use some of the 
     * members functions to check for membership (either if the post requires it
     * of if the user has it).
     */
    
} else {
    global $wpmem;
    
    /**
     * Currently, the most consistent way to check for a login error is as displayed
     * below checking the $wpmem->regchk value.  However, as of 3.5.0, you'll be 
     * able to check $wpmem->error using is_wp_error(): 
     *     is_wp_error( $wpmem->error );
     * Depending on your current version, that may or may not be possible with 
     * versions below 3.5.0.
     */
    if ( 'loginfailed' == $wpmem->regchk ) {
        // The login failed.  You can output the error message with the following:
        echo wpmem_get_display_message( 'loginfailed' );
        
        /**
         * Note: echoing the above is an immediate output. This is suitable where
         * this is being used in a template or elsewhere where direct output is
         * suitable.  If, however, this is within a filter such as the_content, 
         * you need to return a value for content, not echo it. In such cases,
         * you can add this to your return variable:
         * 
         * $content .= wpmem_get_display_message( 'loginfailed' );
         */
        
        // Reprint the login form.
        echo wpmem_login_form();
        
        /**
         * Same as the above - you may want to add this to a return variable
         * instead if you are doing this a filter function:
         * $content .= wpmem_login_form();
         */
        
    } else {
        
        // Login was successful.  Echo (or return) content based on login.
        
    }
}