/**
* Encodes a string
*
* @param mixed $value The value to encode
* @return mixed The result of the encoding process
*/
public function to($string)
{
// Yes, I realize that the iconv methods can handle this, but this method
// can do one thing the iconv encode method cant: Handle encoding without
// a header defined
$string = (string) $string;
// React to the input encoding
$string = iconv($this->getInputEncoding(), $this->getOutputEncoding(), $string);
// Generate the part that describes the encoding
$encodingPart = "=?" . $this->getOutputEncoding() . "?B?";
// Do the actual encoding
$string = base64_encode($string);
// If we aren't doing any wrapping, take the easy out
if ($this->getLineLength() == FALSE) {
return ($this->headerExists() ? $this->getHeader() . ": " : "") . $encodingPart . $string . "?=";
}
// If there is a header to attach, then we need to figure out how many
// characters will fit on the first line with it
if ($this->headerExists()) {
// If the header is so long it won't fit on a line (plus one for the colon)
if ($this->getLineLength() < strlen($this->getHeader()) + 1) {
$err = new \r8\Exception\Data($this->getHeader(), "MIME Header", "Header length exceeds the maximum line length");
$err->addData("Max Line Length", $this->getLineLength());
throw $err;
}
// Line length, minus the Header length, minus two for the colon and
// space, minus the length of the encoding definition, minus two for
// the trailing ?=
$firstLineLength = $this->getLineLength() - strlen($this->getHeader()) - 2 - strlen($encodingPart) - 2;
// Force it to a multiple of 4
$firstLineLength = floor($firstLineLength / 4) * 4;
$prepend = $this->getHeader() . ":";
// If there is room on the first line for at least four characters,
// then add them on
if ($firstLineLength > 0) {
$prepend .= " " . $encodingPart . substr($string, 0, $firstLineLength) . "?=";
$string = substr($string, $firstLineLength);
// If it all fits on the first line, lets get out of here
if ($string == "") {
return $prepend;
}
}
$prepend .= $this->getEOL() . "\t" . $encodingPart;
} else {
$prepend = $encodingPart;
}
// The line length, minus one to compensate for the leading fold, minus
// the length of the encoding definition, minus two for the trailing ?=
$lineLength = $this->getLineLength() - 1 - strlen($encodingPart) - 2;
// Force it to a multiple of four
$lineLength = floor($lineLength / 4) * 4;
// If the required data won't fit on a line, throw an error
if ($lineLength <= 0) {
throw new \r8\Exception\Data($this->getLineLength(), "Max Line Length", "Required content length exceeds the maximum line length");
}
return $prepend . implode("?=" . $this->getEOL() . "\t" . $encodingPart, str_split($string, $lineLength)) . "?=";
}
/**
* Decodes an encoded string
*
* @param mixed $value The value to decode
* @return mixed The original, unencoded value
*/
public function from($string)
{
$string = trim((string) $string);
$string = \r8\str\stripHead($string, "<~");
$string = \r8\str\stripTail($string, "~>");
$length = strlen($string);
$result = "";
$tuple = 0;
$j = 0;
// Loop over each character in the input
for ($i = 0; $i < $length; $i++) {
$chr = $string[$i];
if ($j != 0 && ($chr == "z" || $chr == "y")) {
$err = new \r8\Exception\Data($chr, "Unexpected Character", "Misplaced compression character");
$err->addData("Encoded String", $string);
throw $err;
}
switch ($chr) {
// Add this character to the tuple
default:
// Grab the character code and ensure it is a valid character
$ord = ord($chr) - 33;
if ($ord < 0 || $ord > 84) {
$err = new \r8\Exception\Data($chr, "Invalid Character", "Invalid encoding character");
$err->addData("Encoded String", $string);
throw $err;
}
// Integrate this character into the tuple
$tuple += $ord * pow(85, 4 - $j);
// If this isn't the last character in the tuple, move on
if ($j < 4 && $i != $length - 1) {
$j++;
} else {
// Compensate for an incomplete trailing tuple
if ($j < 4) {
for ($k = $j; $k <= 3; $k++) {
$tuple += 85 * pow(85, 3 - $k);
}
}
// Convert the 32bit integer to binary form
$tuple = str_pad(decbin($tuple), 32, "0", STR_PAD_LEFT);
// Split the binary into 8 bit segments and convert each back to an integer
$tuple = array_map("bindec", str_split($tuple, 8));
if ($j < 4) {
$tuple = array_slice($tuple, 0, $j);
}
// Convert each int into a character, then combine them
$result .= implode("", array_map("chr", $tuple));
// Reset the tuple to prepare for the next substring
$tuple = 0;
$j = 0;
}
break;
// Handle z compression
// Handle z compression
case "z":
$result .= chr(0) . chr(0) . chr(0) . chr(0);
break;
// Handle y compression
// Handle y compression
case "y":
$result .= " ";
break;
// Skip over white space
// Skip over white space
case "\n":
case "\r":
case "\t":
case " ":
case "":
case "\f":
case "":
break;
}
}
return $result;
}
/**
* Renders the template and returns it as a string
*
* @return String Returns the rendered template as a string
*/
public function render()
{
$self = $this;
return preg_replace_callback($this->search, function ($matches) use($self) {
// Ensure that the search string returns the proper number of matches
if (count($matches) < 4) {
$err = new \r8\Exception\Data($self->search, "Search Regular Expression", "Must return at least 3 groupings");
$err->addData("Groupings", count($matches) - 1);
throw $err;
}
// Handle escaped replace strings
if (strlen($matches[1]) % 2 != 0) {
return substr($matches[1], 0, -1) . $matches[2];
} else {
if (!$self->exists($matches[3]) || $self->get($matches[3]) === $self) {
return $matches[1];
} else {
return $matches[1] . (string) $self->get($matches[3]);
}
}
}, $this->template);
}
/**
* Encodes a string
*
* @param mixed $value The value to encode
* @return mixed The result of the encoding process
*/
public function to($string)
{
// Yes, I realize that the iconv methods can handle this, but this method
// can do a few things the iconv encode method cant: Handle encoding without
// a header defined, use the underscore as spaces to save on space.
$string = (string) $string;
// React to the input encoding
$string = iconv($this->getInputEncoding(), $this->getOutputEncoding(), $string);
// This will hold the resulting string
$result = "";
// Generate the part that describes the encoding
$encodingPart = "=?" . $this->getOutputEncoding() . "?Q?";
// This is a running total of the length of the current line
// Once this reaches the max length, the line will be wrapped
$currentLine = 0;
if ($this->headerExists()) {
$result = $this->headerExists() ? $this->getHeader() . ":" : "";
// If the header is so long it won't fit on a line (plus one for the colon)
if ($this->getLineLength() !== FALSE && $this->getLineLength() < strlen($result) + 1) {
$err = new \r8\Exception\Data($this->getHeader(), "MIME Header", "Header length exceeds the maximum line length");
$err->addData("Max Line Length", $this->getLineLength());
throw $err;
}
// If the encoding part and the header can't fit on the same line,
// plus one for the space that hasn't been added yet, plus two for the trailing '?=',
// plus 3 for the length of a single encoded character
if ($this->getLineLength() !== FALSE && strlen($result) + strlen($encodingPart) + 1 + 2 + 3 > $this->getLineLength()) {
$result .= $this->getEOL() . "\t";
} else {
$result .= " ";
// Adjust the offset of the current line to compensate for the length of the header
$currentLine += strlen($result) - 1;
}
}
if ($this->getLineLength() === FALSE) {
$maxLineLength = FALSE;
} else {
// The max line length is the line length, minus one for the fold,
// minus the length of the encoding definition, minus two for the closing ?=
$maxLineLength = $this->getLineLength() - 1 - strlen($encodingPart) - 2;
}
if ($maxLineLength !== FALSE && $maxLineLength <= 0) {
throw new \r8\Exception\Data($this->getLineLength(), "Max Line Length", "Required content length exceeds the maximum line length");
}
// Attach the leading encoding info
$result .= $encodingPart;
// Grab the string length only once
$stringLength = strlen($string);
// Iterate over each character of the string we're encoding
for ($i = 0; $i < $stringLength; $i++) {
// Replace spaces with underscores
if ($string[$i] == " ") {
$result .= "_";
$currentLine++;
} else {
if (ord($string[$i]) <= 32 || ord($string[$i]) >= 127 || $string[$i] == "=" || $string[$i] == "?" || $string[$i] == "_" || $string[$i] == ":") {
$result .= "=" . strtoupper(str_pad(dechex(ord($string[$i])), 2, "0", STR_PAD_LEFT));
$currentLine += 3;
} else {
$result .= $string[$i];
$currentLine++;
}
}
if ($maxLineLength !== FALSE) {
// If we have reached the max characters in a line, and this isn't
// the final character in the string, then wrap
if ($currentLine >= $maxLineLength && $i != $stringLength - 1) {
$result .= "?=" . $this->getEOL() . "\t" . $encodingPart;
$currentLine = 0;
}
}
}
return $result . "?=";
}