Add a rectangle annotation to a PDF in PHP

To add a rectangle annotation to a PDF Document page.

$doc = new PDFDoc($filename);
$page = $doc->GetPage(1);

// Create a rectangle
$sq = Square::Create( $doc->GetSDFDoc(), new Rect(500.0,200.0, 580.0, 300.0 ) );
$sq->SetColor(new ColorPt(1.0, 0.0, 0.0), 3);
$sq->SetInteriorColor(new ColorPt(0.0, 1.0, 1.0), 3);
$sq->SetBorderStyle( new BorderStyle( BorderStyle::e_dashed, 6.0, 0.0, 0.0, array(4.0, 2.0) ) );
$sq->SetPadding( 4.0 );
$sq->RefreshAppearance();
$page->AnnotPushBack( $sq );

Add or edit PDF annotations sample
Full code sample which shows how to add or edit PDF annotations (e.g. hyperlink, intra-document link, stamp, rubber stamp, file attachment, sound, text, free-text, line, circle, square, polygon, polyline, rectangle, squiggly, caret, and ink).