src/Mail/mimePart.php
function Mail_mimePart($body = '', $params = array())
    {
        if (!empty($params['eol'])) {
            $this->_eol = $params['eol'];
        } else if (defined('MAIL_MIMEPART_CRLF')) { // backward-copat.
            $this->_eol = MAIL_MIMEPART_CRLF;
        }

        // Additional part headers
        if (!empty($params['headers']) && is_array($params['headers'])) {
            $headers = $params['headers'];
        }

        foreach ($params as $key => $value) {
            switch ($key) {
            case 'encoding':
                $this->_encoding = $value;
                $headers['Content-Transfer-Encoding'] = $value;
                break;

            case 'cid':
                $headers['Content-ID'] = '<' . $value . '>';
                break;

            case 'location':
                $headers['Content-Location'] = $value;
                break;

            case 'body_file':
                $this->_body_file = $value;
                break;

            // for backward compatibility
            case 'dfilename':
                $params['filename'] = $value;
                break;
            }
        }

        // Default content-type
        if (empty($params['content_type'])) {
            $params['content_type'] = 'text/plain';
        }

        // Content-Type
        $headers['Content-Type'] = $params['content_type'];
        if (!empty($params['charset'])) {
            $charset = "charset={$params['charset']}";
            // place charset parameter in the same line, if possible
            if ((strlen($headers['Content-Type']) + strlen($charset) + 16) <= 76) {
                $headers['Content-Type'] .= '; ';
            } else {
                $headers['Content-Type'] .= ';' . $this->_eol . ' ';
            }
            $headers['Content-Type'] .= $charset;

            // Default headers charset
            if (!isset($params['headers_charset'])) {
                $params['headers_charset'] = $params['charset'];
            }
        }

        // header values encoding parameters
        $h_charset  = !empty($params['headers_charset']) ? $params['headers_charset'] : 'US-ASCII';
        $h_language = !empty($params['language']) ? $params['language'] : null;
        $h_encoding = !empty($params['name_encoding']) ? $params['name_encoding'] : null;


        if (!empty($params['filename'])) {
            $headers['Content-Type'] .= ';' . $this->_eol;
            $headers['Content-Type'] .= $this->_buildHeaderParam(
                'name', $params['filename'], $h_charset, $h_language, $h_encoding
            );
        }

        // Content-Disposition
        if (!empty($params['disposition'])) {
            $headers['Content-Disposition'] = $params['disposition'];
            if (!empty($params['filename'])) {
                $headers['Content-Disposition'] .= ';' . $this->_eol;
                $headers['Content-Disposition'] .= $this->_buildHeaderParam(
                    'filename', $params['filename'], $h_charset, $h_language,
                    !empty($params['filename_encoding']) ? $params['filename_encoding'] : null
                );
            }

            // add attachment size
            $size = $this->_body_file ? filesize($this->_body_file) : strlen($body);
            if ($size) {
                $headers['Content-Disposition'] .= ';' . $this->_eol . ' size=' . $size;
            }
        }

        if (!empty($params['description'])) {
            $headers['Content-Description'] = $this->encodeHeader(
                'Content-Description', $params['description'], $h_charset, $h_encoding,
                $this->_eol
            );
        }

        // Search and add existing headers' parameters
        foreach ($headers as $key => $value) {
            $items = explode(':', $key);
            if (count($items) == 2) {
                $header = $items[0];
                $param  = $items[1];
                if (isset($headers[$header])) {
                    $headers[$header] .= ';' . $this->_eol;
                }
                $headers[$header] .= $this->_buildHeaderParam(
                    $param, $value, $h_charset, $h_language, $h_encoding
                );
                unset($headers[$key]);
            }
        }

        // Default encoding
        if (!isset($this->_encoding)) {
            $this->_encoding = '7bit';
        }

        // Assign stuff to member variables
        $this->_encoded  = array();
        $this->_headers  = $headers;
        $this->_body     = $body;
    }
function Mail_mimePart($body = '', $params = array())
    {
        if (!empty($params['eol'])) {
            $this->_eol = $params['eol'];
        } else if (defined('MAIL_MIMEPART_CRLF')) { // backward-copat.
            $this->_eol = MAIL_MIMEPART_CRLF;
        }

        // Additional part headers
        if (!empty($params['headers']) && is_array($params['headers'])) {
            $headers = $params['headers'];
        }

        foreach ($params as $key => $value) {
            switch ($key) {
            case 'encoding':
                $this->_encoding = $value;
                $headers['Content-Transfer-Encoding'] = $value;
                break;

            case 'cid':
                $headers['Content-ID'] = '<' . $value . '>';
                break;

            case 'location':
                $headers['Content-Location'] = $value;
                break;

            case 'body_file':
                $this->_body_file = $value;
                break;

            // for backward compatibility
            case 'dfilename':
                $params['filename'] = $value;
                break;
            }
        }

        // Default content-type
        if (empty($params['content_type'])) {
            $params['content_type'] = 'text/plain';
        }

        // Content-Type
        $headers['Content-Type'] = $params['content_type'];
        if (!empty($params['charset'])) {
            $charset = "charset={$params['charset']}";
            // place charset parameter in the same line, if possible
            if ((strlen($headers['Content-Type']) + strlen($charset) + 16) <= 76) {
                $headers['Content-Type'] .= '; ';
            } else {
                $headers['Content-Type'] .= ';' . $this->_eol . ' ';
            }
            $headers['Content-Type'] .= $charset;

            // Default headers charset
            if (!isset($params['headers_charset'])) {
                $params['headers_charset'] = $params['charset'];
            }
        }

        // header values encoding parameters
        $h_charset  = !empty($params['headers_charset']) ? $params['headers_charset'] : 'US-ASCII';
        $h_language = !empty($params['language']) ? $params['language'] : null;
        $h_encoding = !empty($params['name_encoding']) ? $params['name_encoding'] : null;


        if (!empty($params['filename'])) {
            $headers['Content-Type'] .= ';' . $this->_eol;
            $headers['Content-Type'] .= $this->_buildHeaderParam(
                'name', $params['filename'], $h_charset, $h_language, $h_encoding
            );
        }

        // Content-Disposition
        if (!empty($params['disposition'])) {
            $headers['Content-Disposition'] = $params['disposition'];
            if (!empty($params['filename'])) {
                $headers['Content-Disposition'] .= ';' . $this->_eol;
                $headers['Content-Disposition'] .= $this->_buildHeaderParam(
                    'filename', $params['filename'], $h_charset, $h_language,
                    !empty($params['filename_encoding']) ? $params['filename_encoding'] : null
                );
            }

            // add attachment size
            $size = $this->_body_file ? filesize($this->_body_file) : strlen($body);
            if ($size) {
                $headers['Content-Disposition'] .= ';' . $this->_eol . ' size=' . $size;
            }
        }

        if (!empty($params['description'])) {
            $headers['Content-Description'] = $this->encodeHeader(
                'Content-Description', $params['description'], $h_charset, $h_encoding,
                $this->_eol
            );
        }

        // Search and add existing headers' parameters
        foreach ($headers as $key => $value) {
            $items = explode(':', $key);
            if (count($items) == 2) {
                $header = $items[0];
                $param  = $items[1];
                if (isset($headers[$header])) {
                    $headers[$header] .= ';' . $this->_eol;
                }
                $headers[$header] .= $this->_buildHeaderParam(
                    $param, $value, $h_charset, $h_language, $h_encoding
                );
                unset($headers[$key]);
            }
        }

        // Default encoding
        if (!isset($this->_encoding)) {
            $this->_encoding = '7bit';
        }

        // Assign stuff to member variables
        $this->_encoded  = array();
        $this->_headers  = $headers;
        $this->_body     = $body;
    }
Constructor.

Sets up the object.

@param string $body   The body of the mime part if any.
@param array  $params An associative array of optional parameters:
content_type      - The content type for this part eg multipart/mixed
encoding          - The encoding to use, 7bit, 8bit,
base64, or quoted-printable
charset           - Content character set
cid               - Content ID to apply
disposition       - Content disposition, inline or attachment
filename          - Filename parameter for content disposition
description       - Content description
name_encoding     - Encoding of the attachment name (Content-Type)
By default filenames are encoded using RFC2231
Here you can set RFC2047 encoding (quoted-printable
or base64) instead
filename_encoding - Encoding of the attachment filename (Content-Disposition)
See 'name_encoding'
headers_charset   - Charset of the headers e.g. filename, description.
If not set, 'charset' will be used
eol               - End of line sequence. Default: "\r\n"
headers           - Hash array with additional part headers. Array keys can be
in form of <header_name>:<parameter_name>
body_file         - Location of file with part's body (instead of $body)

@access public