Translator.php

<?php

/**
 * This is basically $txt, but a lot smarter
 * @todo add Language classes for each language then move the language files to classes (\Translator\English\PostLanguage) to allow for namespacing
 *       instead of global $txt, the class would implement LanguageFileInterface which has public getText()
 *       
 */
class Translator extends ArrayObject
{
	const ERROR_SELECTED_LANG_NOT_LOADED = 'The selected language has not been loaded.';
	const ERROR_NO_LANG_LOADED           = 'No languages are loaded.';
	const ERROR_NO_DEFAULT_LANG          = 'The default language has not been loaded.';

	protected $default_language = 'english';
	protected $default_fallback = false;
	protected $loaded_languages = array();
	protected $current_language;

	public function __get($var)
	{
		return $this->get($var);
	}

	public function __set($var, $val)
	{
		return $this->set($var, $val);
	}

	/**
	 * Get a language string (or whatever the type)
	 * 
	 * @param string $var
	 * @param string $language = null
	 * @return mixed
	 * @throws TranslatorException if the language hasn't been loaded
	 */
	public function get($var, $language = null)
	{
		// No language selected
		if (null === $language)
		{
			if (isset($this->contents[$var]))
			{
				return $this->contents[$var];
			}
			elseif ($this->default_fallback)
			{
				$language = $this->default_language;
			}
			// We just can't find your entry
			else
			{
				return;
			}
		}

		if (!$this->isLoaded($language))
		{
			throw new TranslatorException($this->_('error.selected_lang_not_loaded', self::ERROR_SELECTED_LANG_NOT_LOADED));
		}

		return isset($this->loaded_languages[$language][$var]) ? $this->loaded_languages[$language][$var] : null;
	}

	/**
	 * 
	 * @param string $var
	 * @param mixed $val
	 * @param string $language = null
	 * @return \Translator
	 * @throws TranslatorException if the $language has not been loaded
	 */
	public function set($var, $val, $language = null)
	{
		if (null === $language)
		{
			$this->contents[$var] = $val;
		}
		else
		{
			if (!$this->isLoaded($language))
			{
				throw new TranslatorException($this->_('error.selected_lang_not_loaded', self::ERROR_SELECTED_LANG_NOT_LOADED));
			}

			$this->loaded_languages[$language][$var] = $val;
		}

		return $this;
	}

	/**
	 * Select a language to use
	 * @param string $language
	 * @return \Translator
	 * @throws TranslatorException if $language has not been loaded
	 */
	public function selectLanguage($language)
	{
		if (!$this->isLoaded($language))
		{
			throw new TranslatorException($this->_('error.selected_lang_not_loaded', self::ERROR_SELECTED_LANG_NOT_LOADED));
		}

		$this->current_language = $language;

		// Note: this is a reference so that it can change
		$this->contents = &$this->loaded_languages[$language];

		return $this;
	}

	/**
	 * Get which language we're using
	 * @return string
	 */
	public function getCurrentLanguage()
	{
		return $this->current_language;
	}

	/**
	 * Check if a language has been loaded
	 * @param string $language
	 * @return bool
	 */
	public function isLoaded($language)
	{
		return isset($this->loaded_languages[$language]);
	}

	/**
	 * Remove a loaded language
	 * 
	 * @param type $language
	 * @return \Translator
	 * @throws TranslatorException
	 */
	public function removeLanguage($language)
	{
		if (!$this->isLoaded($language))
		{
			throw new TranslatorException($this->_('error.selected_lang_not_loaded', self::ERROR_SELECTED_LANG_NOT_LOADED));
		}

		if ($this->isLoaded($this->default_language))
		{
			$this->current_language = $this->default_language;
		}
		elseif (false === reset($this->loaded_languages))
		{
			throw new TranslatorException($this->_('error.no_lang_loaded', self::ERROR_NO_LANG_LOADED));
		}

		return $this;
	}

	/**
	 * @see loadLanguage()
	 * @param string $file
	 * @param string $language
	 * @return \Translator
	 */
	public function load($file, $language = null)
	{
		// Set the current language to this
		// Instead of include() and then $txt being in the global scope and instead of using classes, just use return

		return $this;
	}

	/**
	 * Set the fallback language if a key cannot be found
	 * 
	 * @param bool|string $language
	 * @return \Translator
	 * @throws TranslatorException
	 */
	public function setDefaultFallback($language)
	{
		if (false === (bool) $language)
		{
			$this->default_fallback = (bool) $language;
		}
		else
		{
			if (true === $language)
			{
				$language = $this->default_language;
			}
			else
			{
				$this->default_language = $language;
			}
		}

		if ($this->default_fallback && !$this->isLoaded($language))
		{
			throw new TranslatorException($this->_('error.no_default_lang', self::ERROR_NO_DEFAULT_LANG));
		}

		return $this;
	}

	/**
	 * Get all of the loaded language names
	 * 
	 * @return array
	 */
	public function getLoadedLanguages()
	{
		return array_keys($this->loaded_languages);
	}

	/**
	 * Get a language string if found. Otherwise, just return the default string
	 * 
	 * @param type $key The language string key
	 * @param string $string Gets returned if $key isn't found
	 * @return mixed
	 */
	public function _($key, $string = '')
	{
		return isset($this->contents[$key]) ? $this->contents[$key] : $string;
	}
}