Bitrix: setting If-Modified-Since headers

The heading Last-Modified is a fairly common wish of seo specialists. Unfortunately, Bitrix does not allow setting last-modified headers out of the box. So I applied a trick: I split all pages into 2 boolean types - static and dynamic.

- For static pages I set the title by the time of the last modification of the file in which they are located.

- For dynamic pages in each template, I display the last modification of the page by the time the last element was added or updated.

Providing headings

In init.php we write

  / * Expose headers if-modified-since * /
require ($ _ SERVER ['DOCUMENT_ROOT']. '/ local / libs / if-modified-since.php');  

In if-modified-since.php

  / * Expose headers if-modified-since * /
AddEventHandler ('main', 'OnEpilog', array ('CBDPEpilogHooks', 'CheckIfModifiedSince'));
class CBDPEpilogHooks
{
    function CheckIfModifiedSince ()
    {
        GLOBAL $ lastModified;

        if (! $ lastModified) $ lastModified = time () - rand (1000, 100000);

        if ($ lastModified)
        {
            header ("Cache-Control: public");
            header ('Last-Modified:' .gmdate ('D, d M Y H: i: s', $ lastModified). 'GMT');

            if (isset ($ _ SERVER ['HTTP_IF_MODIFIED_SINCE']) && strtotime ($ _ SERVER ['HTTP_IF_MODIFIED_SINCE'])> = $ lastModified) {
                header ('HTTP / 1.1 304 Not Modified'); exit ();
            }
        }
    }
}  

If-Modified-Since for static pages

Write somewhere in the file.

  GLOBAL $ lastModified;
if (! $ lastModified) {
    $ lastModified = strtotime (date ("D, d M Y H: i: s", filectime ($ _ SERVER ['SCRIPT_FILENAME'])));
} else {
    $ lastModified = max ($ lastModified, MakeTimeStamp ($ arResult ['TIMESTAMP_X']));
}  

If-Modified-Since for dynamic list of items

In result_modifier.php

  if (! empty ($ arResult ['ITEMS'])) {
    $ time = strtotime ("- 5 years", time ());
    $ date = date ("Y-m-d", $ time);

    $ dat ['DATE'] = $ date;
    foreach ($ arResult ['ITEMS'] as $ key => $ value) {
        if ($ value ['DATE_CREATE'] && strtotime ($ dat ['DATE'])  __ component-> arResult ["LAST_MODIFY"] = $ dat ['DATE'];
    $ this -> __ component-> SetResultCacheKeys (array ("LAST_MODIFY"));
}  

In component_epilog.php

  GLOBAL $ lastModified;
$ lastModified = strtotime ($ arResult ['LAST_MODIFY']);  

If-Modified-Since for complex component detail pages

In component_epilog.php

  GLOBAL $ lastModified;
$ m = $ arResult ['TIMESTAMP_X']? $ arResult ['TIMESTAMP_X']: $ arResult ['DATE_CREATE'];

if (! $ m) {
    $ lastModified = strtotime (date ("D, d M Y H: i: s", filectime ($ _ SERVER ['SCRIPT_FILENAME'])));
} else {
    $ lastModified = MakeTimeStamp ($ m);
} 

Do not forget to select "Creation date" and "Modification date" in the fields for displaying in the settings of complex components

After adding the code, you will need to update the component cache or completely reset it

I have not tested the compatibility of this solution with the composite

The best place to check the returned headers is here: Last- Modified.com

Теги: 1C Bitrixeventsinit.phpphp