Bitrix Framework

when a website is determined using the current domain name:

 <?
// we connect the file with the CMainPage class
require($_SERVER['DOCUMENT_ROOT']."/bitrix/modules/main/include/mainpage.php");

// we obtain the ID of the current website using the domain name
$site_id = CMainPage::GetSiteByHost();

// we obtain the absolute path to the index page of the website folder
$page = CMainPage::GetIncludeSitePage($site_id);

// if the website is determined and the index page is determined
if(strlen($site_id)>0 && strlen($page)>0) 
{
    // we connect the page
    require_once($page);
}
else // otherwise, if the website is not determined
{
    require($_SERVER['DOCUMENT_ROOT']."/bitrix/header.php");
    // a code may be provided to be displayed if
    // the website was not determined earlier
    ?>

    <?require($_SERVER['DOCUMENT_ROOT']."/bitrix/footer.php");
}
?>

This code example determines the domain name used by a visitor with the help of the function CMainPage::GetSiteByHost, compares this domain name with the names stored in the website settings in the field Domain name in order to determine the website ID and connects the index page into the body of the document from the folder of the relevant website using the function CMainPage::GetIncludeSitePage.

In our example, it will mean that the page /s1/index.php will be shown directly in the body of the current page without redirection to a visitor who came to the address http://www.site1.com. And the page /s2/index.php – to a visitor who came to the address: http://www.site2.com.

This algorithm permits avoiding redirections for users and search bots and ensures convenient work with multisiting configuration. This algorithm is recommended but it is not the only one available for work with a multiple site version.

when a website is determined using the languages set in the user’s browser:

<?
// we connect a CMainPage class file
require($_SERVER['DOCUMENT_ROOT']."/bitrix/modules/main/include/mainpage.php");

// obtain website ID by Accept-Language
$site_id = CMainPage::GetSiteByAcceptLanguage();

// if the website is determined 
if(strlen($site_id)>0) 
{
    // we redirect to the index page of the website
    CMainPage::RedirectToSite($site_id);
}
else // otherwise, if the website is not determined,
{
    require($_SERVER['DOCUMENT_ROOT']."/bitrix/header.php");
    // a code may be provided to be displayed if
    // the website was not determined earlie
    ?>

    <?require($_SERVER['DOCUMENT_ROOT']."/bitrix/footer.php");
}
?>

In this example of the code, the function CMainPage::GetSiteByAcceptLanguage checks which languages are set in the settings of the visitor’s browser, compares them with the language ID of the website, and returns the most suitable website.

Once the website is determined, the function CMainPage::RedirectToSite will perform redirection (web server response 302), and redirect the user to the index page of the folder of the indicated website, e.g. to http://www.site1.com/s1/ or http://www.site2.com/s2/.

when one website is located in the root and others in folders, and at the same time the websites have the same hosts:

<?
// We connect a CMainPage class file
require($_SERVER['DOCUMENT_ROOT']."/bitrix/modules/main/include/mainpage.php");

// obtain website ID of the current website using the domain name
$mainpage_siteid = CMainPage::GetSiteByHost();

// if the current website is s2, we will obtain the absolute path to the index page of the website folder 
if ($mainpage_siteid != "s1" && $page = CMainPage::GetIncludeSitePage($mainpage_siteid)):
// connect the page
    require_once($page);
    die();
endif;

 require($_SERVER['DOCUMENT_ROOT']."/bitrix/header.php");
    // then we can place a normal text of the index page, 
    // which will be connected when the website located in the root of is active
    
 <?require($_SERVER['DOCUMENT_ROOT']."/bitrix/footer.php");
?>

In our example, if the "default" website (from websites’ settings) is s2, it is this website’s index page that will be displayed.

If your websites are in fact different international language mirrors, you can use the option of determining a website according to the languages installed in the visitor’s browser.