Helper functions

string_functions.inc.php

<?php

/**
 * creates a data url
 *
 * @version: 1.0
 *
 * @param  string $data            Data string that should be encoded
 * @param  string [$mime]          Mime Type of the data (optional)
 * @param  string [$charset]       charset of data (only used when it is not base64) (optional)
 * @param  bool   [$base64]        Should data be decoded as base64 - If NULL, base64 is detected by the content-type
 *
 * @return String Data uri
 *
 */
function data_uri($data, $mime = "", $charset = "", $base64 = null)
{
  // skip minetype for this case, because "text/plain" is default
  if($mime == "text/plain" || trim($mime) == "") $mime = "";
  // Charset is US_ASCII by default, so wie can omit this here
  $charset = ($charset == "US-ASCII" || $charset == "")
    ? ""
    : ";charset=" . $charset;

  // if $base64 is not set, choose by content-type
  if(is_null($base64))
  {
    if(stripos($mime, "text/") === 0)
      $base64 = false;
    else {
      switch (trim($mime)) {
        // list of all non "text/*" types that should no be base64 encoded
        case "image/svg+xml":
        {
          $base64 = false;
          break;
        }
        default:
          $base64 = true;
      }
    }
  }

?>