wiki.techinc.nl/includes/api/ApiFormatYaml_spyc.php

<?php
/**
 * Spyc -- A Simple PHP YAML Class
 * @version 0.2.3 -- 2006-02-04
 * @author Chris Wanstrath <chris@ozmm.org>
 * @see http://spyc.sourceforge.net/
 * @copyright Copyright 2005-2006 Chris Wanstrath
 * @license http://www.opensource.org/licenses/mit-license.php MIT License
 */

/**
 * The Simple PHP YAML Class.
 *
 * This class can be used to read a YAML file and convert its contents
 * into a PHP array.  It currently supports a very limited subsection of
 * the YAML spec.
 *
 * @ingroup API
 */
class Spyc {

	/**
	 * Dump YAML from PHP array statically
	 *
	 * The dump method, when supplied with an array, will do its best
	 * to convert the array into friendly YAML.  Pretty simple.  Feel free to
	 * save the returned string as nothing.yml and pass it around.
	 *
	 * Oh, and you can decide how big the indent is and what the wordwrap
	 * for folding is.  Pretty cool -- just pass in 'false' for either if
	 * you want to use the default.
	 *
	 * Indent's default is 2 spaces, wordwrap's default is 40 characters.  And
	 * you can turn off wordwrap by passing in 0.
	 *
	 * @return string
	 * @param $array Array: PHP array
	 * @param $indent Integer: Pass in false to use the default, which is 2
	 * @param $wordwrap Integer: Pass in 0 for no wordwrap, false for default (40)
	 */
	public static function YAMLDump($array,$indent = false,$wordwrap = false) {
		$spyc = new Spyc;
		return $spyc->dump($array,$indent,$wordwrap);
	}

	/**
	 * Dump PHP array to YAML
	 *
	 * The dump method, when supplied with an array, will do its best
	 * to convert the array into friendly YAML.  Pretty simple.  Feel free to
	 * save the returned string as tasteful.yml and pass it around.
	 *
	 * Oh, and you can decide how big the indent is and what the wordwrap
	 * for folding is.  Pretty cool -- just pass in 'false' for either if
	 * you want to use the default.
	 *
	 * Indent's default is 2 spaces, wordwrap's default is 40 characters.  And
	 * you can turn off wordwrap by passing in 0.
	 *
	 * @public
	 * @return string
	 * @param $array Array: PHP array
	 * @param $indent Integer: Pass in false to use the default, which is 2
	 * @param $wordwrap Integer: Pass in 0 for no wordwrap, false for default (40)
	 */
	function dump($array,$indent = false,$wordwrap = false) {
		// Dumps to some very clean YAML.  We'll have to add some more features
		// and options soon.  And better support for folding.

		// New features and options.
		if ($indent === false or !is_numeric($indent)) {
			$this->_dumpIndent = 2;
		} else {
			$this->_dumpIndent = $indent;
		}

		if ($wordwrap === false or !is_numeric($wordwrap)) {
			$this->_dumpWordWrap = 40;
		} else {
			$this->_dumpWordWrap = $wordwrap;
		}

		// New YAML document
		$string = "---\n";

		// Start at the base of the array and move through it.
		foreach ($array as $key => $value) {
			$string .= $this->_yamlize($key,$value,0);
		}
		return $string;
	}

	/**** Private Properties ****/

	private $_haveRefs;
	private $_allNodes;
	private $_lastIndent;
	private $_lastNode;
	private $_inBlock;
	private $_isInline;
	private $_dumpIndent;
	private $_dumpWordWrap;

	/**** Private Methods ****/

	/**
	 * Attempts to convert a key / value array item to YAML
	 * @return string
	 * @param $key The name of the key
	 * @param $value The value of the item
	 * @param $indent The indent of the current node
	 */
	private function _yamlize($key,$value,$indent) {
		if (is_array($value)) {
			// It has children.  What to do?
			// Make it the right kind of item
			$string = $this->_dumpNode($key,NULL,$indent);
			// Add the indent
			$indent += $this->_dumpIndent;
			// Yamlize the array
			$string .= $this->_yamlizeArray($value,$indent);
		} elseif (!is_array($value)) {
			// It doesn't have children.  Yip.
			$string = $this->_dumpNode($key,$value,$indent);
		}
		return $string;
	}

	/**
	 * Attempts to convert an array to YAML
	 * @return string
	 * @param $array The array you want to convert
	 * @param $indent The indent of the current level
	 */
	private function _yamlizeArray($array,$indent) {
		if (is_array($array)) {
			$string = '';
			foreach ($array as $key => $value) {
				$string .= $this->_yamlize($key,$value,$indent);
			}
			return $string;
		} else {
 			return false;
		}
    }

	/**
	 * Find out whether a string needs to be output as a literal rather than in plain style.
	 * Added by Roan Kattouw 13-03-2008
	 * @param $value The string to check
	 * @return bool
	 */
	function _needLiteral($value) {
		# Check whether the string contains # or : or begins with any of:
		# [ - ? , [ ] { } ! * & | > ' " % @ ` ]
		# or is a number or contains newlines
		return (bool)(gettype($value) == "string" &&
			(is_numeric($value)  ||
			strpos($value, "\n") ||
			preg_match("/[#:]/", $value) ||
			preg_match("/^[-?,[\]{}!*&|>'\"%@`]/", $value)));

	}

	/**
	 * Returns YAML from a key and a value
	 * @return string
	 * @param $key The name of the key
	 * @param $value The value of the item
	 * @param $indent The indent of the current node
	 */
	private function _dumpNode($key,$value,$indent) {
		// do some folding here, for blocks
		if ($this->_needLiteral($value)) {
			$value = $this->_doLiteralBlock($value,$indent);
		} else {
			$value  = $this->_doFolding($value,$indent);
		}

		$spaces = str_repeat(' ',$indent);

		if (is_int($key)) {
			// It's a sequence
			if ($value !== '' && !is_null($value))
				$string = $spaces.'- '.$value."\n";
			else
				$string = $spaces . "-\n";
		} else {
			// It's mapped
			if ($value !== '' && !is_null($value))
				$string = $spaces . $key . ': ' . $value . "\n";
			else
				$string = $spaces . $key . ":\n";
		}
		return $string;
	}

	/**
	 * Creates a literal block for dumping
	 * @return string
	 * @param $value
	 * @param $indent int The value of the indent
	 */
	private function _doLiteralBlock($value,$indent) {
		$exploded = explode("\n",$value);
		$newValue = '|';
		$indent  += $this->_dumpIndent;
		$spaces   = str_repeat(' ',$indent);
		foreach ($exploded as $line) {
			$newValue .= "\n" . $spaces . trim($line);
		}
		return $newValue;
	}

	/**
	 * Folds a string of text, if necessary
	 * @return string
	 * @param $value The string you wish to fold
	 */
	private function _doFolding($value,$indent) {
		// Don't do anything if wordwrap is set to 0
		if ($this->_dumpWordWrap === 0) {
			return $value;
		}

		if (strlen($value) > $this->_dumpWordWrap) {
			$indent += $this->_dumpIndent;
			$indent = str_repeat(' ',$indent);
			$wrapped = wordwrap($value,$this->_dumpWordWrap,"\n$indent");
			$value   = ">\n".$indent.$wrapped;
		}
		return $value;
	}
}