silverstripe-translatable/code/controller/TranslatableCMSMainExtension.php

<?php
/**
 * @package translatable
 */
class TranslatableCMSMainExtension extends Extension {

	static $allowed_actions = array(
		'createtranslation',
	);

	function init() {
		// Locale" attribute is either explicitly added by LeftAndMain Javascript logic,
		// or implied on a translated record (see {@link Translatable->updateCMSFields()}).
		// $Lang serves as a "context" which can be inspected by Translatable - hence it
		// has the same name as the database property on Translatable.
		$req = $this->owner->getRequest();
		if($req->requestVar("Locale")) {
			$this->owner->Locale = $req->requestVar("Locale");
		} elseif($req->requestVar("locale")) {
			$this->owner->Locale = $req->requestVar("locale");
		} else {
			$this->owner->Locale = Translatable::default_locale();
		}
		Translatable::set_current_locale($this->owner->Locale);
		
		// collect languages for TinyMCE spellchecker plugin.
		// see http://wiki.moxiecode.com/index.php/TinyMCE:Plugins/spellchecker
		$langName = i18n::get_locale_name($this->owner->Locale);
		HtmlEditorConfig::get('cms')->setOption('spellchecker_languages', "+{$langName}={$this->owner->Locale}");
		
		Requirements::javascript('translatable/javascript/CMSMain.Translatable.js');
		Requirements::css('translatable/css/CMSMain.Translatable.css');
	}
	
	function updateEditForm(&$form) {
		$siteConfig = SiteConfig::current_site_config();
		if($form->Name() == 'RootForm' && Object::has_extension('SiteConfig',"Translatable")) {
			$form->Fields()->push(new HiddenField('Locale','', $siteConfig->Locale));
		}
	}
	
	function updatePageOption(&$fields) {
		$fields->push(new HiddenField("Locale", 'Locale', Translatable::get_current_locale()));
	}
	
	/**
	 * Create a new translation from an existing item, switch to this language and reload the tree.
	 */
	function createtranslation($request) {
		// Protect against CSRF on destructive action
		if(!SecurityToken::inst()->checkRequest($request)) return $this->owner->httpError(400);
		
		$langCode = Convert::raw2sql($request->getVar('newlang'));
		$originalLangID = (int)$request->getVar('ID');

		$record = $this->owner->getRecord($originalLangID);
		
		$this->owner->Locale = $langCode;
		Translatable::set_current_locale($langCode);
		
		// Create a new record in the database - this is different
		// to the usual "create page" pattern of storing the record
		// in-memory until a "save" is performed by the user, mainly
		// to simplify things a bit.
		// @todo Allow in-memory creation of translations that don't persist in the database before the user requests it
		$translatedRecord = $record->createTranslation($langCode);

		$url = sprintf(
			"%s/%d/?locale=%s", 
			$this->owner->Link('show'),
			$translatedRecord->ID,
			$langCode
		);

		return Director::redirect($url);
	}
	
	/**
	 * Returns a form with all languages with languages already used appearing first.
	 * 
	 * @return Form
	 */
	function LangForm() {
		$member = Member::currentUser(); //check to see if the current user can switch langs or not
		if(Permission::checkMember($member, 'VIEW_LANGS')) {
			$field = new LanguageDropdownField(
				'Locale', 
				_t('CMSMAIN.LanguageDropdownLabel', 'Language'), 
				array(), 
				'SiteTree', 
				'Locale-English',
				singleton('SiteTree')
			);
			$field->setValue(Translatable::get_current_locale());
        } else {
			// user doesn't have permission to switch langs 
			// so just show a string displaying current language
			$field = new LiteralField(
				'Locale', 
				i18n::get_locale_name( Translatable::get_current_locale())
			);
		}
		
		$form = new Form(
			$this->owner,
			'LangForm',
			new FieldSet(
				$field
			),
			new FieldSet(
				new FormAction('selectlang', _t('CMSMain_left.ss.GO','Go'))
			)
		);
		$form->unsetValidator();
		
		return $form;
	}
	
	function selectlang($data, $form) {
		return $this->owner;
	}
	
	/**
	 * Determine if there are more than one languages in our site tree.
	 * 
	 * @return boolean
	 */
	function MultipleLanguages() {
		$langs = Translatable::get_existing_content_languages('SiteTree');

		return (count($langs) > 1);
	}
	
	/**
	 * @return boolean
	 */
	function IsTranslatableEnabled() {
		return Object::has_extension('SiteTree', 'Translatable');
	}
	
}