Refactor filter_input usage throughout Stream

[frankiejarrett]

Recently there was a discussion around the use of PHP filter_* functions after a user reported having an issue in the WP.org forum.

@westonruter then informed us that for reasons of reliability Nacin doesn't allow these to be used in core. I think we should follow suite in Stream to avoid potential issues and stay in line with core coding standards.

See #254 (comment)

[frankiejarrett]

It was suggested by @powelski that perhaps we add a helper function to Stream that does the isset check for us and returns false otherwise. Maybe this would be better than doing it longhand every time.

Could just be something like:

stream_input( $type, $var ) {
    if ( ! is_string( $type ) || ! is_string( $var ) ) {
        return false;
    }

    $result = ( 'INPUT_GET' === $type && isset( $_GET[$var] ) ) ? $_GET[$var] : false;
    $result = ( 'INPUT_POST' === $type && isset( $_POST[$var] ) ) ? $_POST[$var] : false;
    $result = ( 'INPUT_SERVER' === $type && isset( $_SERVER[$var] ) ) ? $_SERVER[$var] : false;

    return $result;
}

[powelski]

@fjarrett How about making it array-friendly by providing any array as the first argument? So we would call it like:

stream_input( $_GET, 'key', array( 'default_param' => 'default_value' ) );

Where the third argument is optional.

[shadyvb]

@powelski I'd suggest we use the same syntax as filter_input family so we minimize the effort needed to change what is written already, and to maintain compatibility in case they come back in new suits in new PHP versions.

[frankiejarrett]

+1

[jonathanbardo]

@shadyvb I agree. Should stay with API parity.

[shadyvb]

Noticed couple of filter_var's in plugin code , will try to accommodate.

[frankiejarrett]

@shadyvb Please create a new issue for the filter_var usage. Sorry I missed your comment and already merged and released the PR.

[shadyvb]

@fjarrett I believe filter_var functionality were merged to the master branch already, let me know if something still needs to be done.