=== Add Headers === Contributors: gnotaras Tags: Requires at least: 3.1.0 Tested up to: 4.5 Stable tag: 2.0.1 License: GPLv3 License URI: http://www.gnu.org/licenses/gpl-3.0.txt Adds the ETag, Last-Modified, Expires and Cache-Control headers to HTTP responses generated by WordPress. [DEPRECATED] == Description == Adds the *ETag*, *Last-Modified*, *Expires* and *Cache-Control* headers to HTTP responses generated by WordPress for more efficient caching. **NOTICE:** THIS PLUGIN HAS BEEN **DEPRECATED**. IT IS NO LONGER SUPPORTED. IT IS NO LONGER TESTED WITH NEW WORDPRESS RELEASES. USING IT IN PRODUCTION IS NOT RECOMMENDED. IT IS STRONGLY SUGGESTED TO MIGRATE TO OTHER MORE MODERN AND BETTER MAINTAINED PLUGINS. IF YOU ARE STARTING A NEW BLOG, IT IS HIGHLY RECOMMENDED TO SEARCH FOR OTHER PLUGINS IN ORDER TO AVOID THE INEVITABLE FUTURE MIGRATION. REGARDING EXISTING USERS, AT THE TIME OF WRITING, THERE ARE NO MAJOR BUGS. PROVIDED THAT THE WORDPRESS API DOES NOT CHANGE SOON, YOU HAVE THE TIME TO EXPERIMENT WITH OTHER PLUGINS AND PLAN YOUR MIGRATION. = Official Project Homepage = The Add-Headers documentation has been moved to the [Add-Headers Development Web Site](http://www.codetrax.org/projects/wp-add-headers/wiki). = Support = *Add-Headers* is released without support of any kind. = Legal Notice = Add-Headers is Copyright (c) 2013-2016 George Notaras. All rights reserved. Permission is granted to use this software under the terms of the GNU General Public License version 3 or newer. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE. == Installation == Add-Headers can be easily installed through the plugin management interface of WordPress. == Upgrade Notice == No special requirements when upgrading. == Frequently Asked Questions == Please read the [Add-Headers FAQ](http://www.codetrax.org/projects/wp-add-headers/wiki/FAQ) at the development web site. == Screenshots == No screenshots are available at this time. == Changelog == **NOTICE:** THIS PLUGIN HAS BEEN **DEPRECATED**. IT IS NO LONGER SUPPORTED. IT IS NO LONGER TESTED WITH NEW WORDPRESS RELEASES. USING IT IN PRODUCTION IS NOT RECOMMENDED. IT IS STRONGLY SUGGESTED TO MIGRATE TO OTHER MORE MODERN AND BETTER MAINTAINED PLUGINS. IF YOU ARE STARTING A NEW BLOG, IT IS HIGHLY RECOMMENDED TO SEARCH FOR OTHER PLUGINS IN ORDER TO AVOID THE INEVITABLE FUTURE MIGRATION. REGARDING EXISTING USERS, AT THE TIME OF WRITING, THERE ARE NO MAJOR BUGS. PROVIDED THAT THE WORDPRESS API DOES NOT CHANGE SOON, YOU HAVE THE TIME TO EXPERIMENT WITH OTHER PLUGINS AND PLAN YOUR MIGRATION. = Changelog Entries = Please check out the changelog of each release by following the links below. You can also check the [roadmap](http://www.codetrax.org/projects/wp-add-headers/roadmap "Add-Headers Roadmap") regarding future releases of the plugin. - [2.0.1](http://www.codetrax.org/versions/314) - This release introduces the concept of setting a different caching timeout on _old content_. For this reason two new options have been added: [cache_old_content_threshold_seconds](http://www.codetrax.org/projects/wp-add-headers/wiki/Configuration#cache_old_content_threshold_seconds) and [cache_old_content_max_age_seconds](http://www.codetrax.org/projects/wp-add-headers/wiki/Configuration#cache_old_content_max_age_seconds). Please see this [configuration example](http://www.codetrax.org/projects/wp-add-headers/wiki/Configuration#Different-caching-timeout-for-old-content) that demonstrates this functionality. - Minor improvements and fixes. - [2.0.0](http://www.codetrax.org/versions/313) - IMPORTANT CHANGE OF THE DEFAULT FUNCTIONALITY: Since the v2.0.0 major release, no page is allowed to be cached by default. Caching needs to be enabled by [configuring](http://www.codetrax.org/projects/wp-add-headers/wiki/Configuration) the plugin. - Improved the header generation mechanism. New header array format: `['HEADER_NAME'] => 'HEADER_VALUE'` - Added the `remove_pre_existing_headers` option. When enabled, it instructs the plugin to clear any preexisting ETag, Last-Modified, Expires, Cache-Control and Pragma headers before sending its own headers, according to the user defined options. - Other minor fixes and improvements. - [1.2.1](http://www.codetrax.org/versions/243) - Instead of `Pragma: cache`, now sends `Pragma: public`. This is not included in any standard. The `public` value is used by convention. - The array that holds the headers just before sending them to the clients now has proper keys for easier header isolation when filtering. - Fixed a small bug that happened whenever a taxonomy archive without any posts was visited. - [1.2.0](http://www.codetrax.org/versions/242) - New option added: `cache_max_age_seconds_for_authenticated_users` initially set to 0 seconds. If you need cached content for authenticated users, adjust this accordingly. - The `Pragma` header is now also sent with a value of `no-cache` or `cache` according to *Cache-Control* header's `max-age`. - [1.1.2](http://www.codetrax.org/versions/235) - [1.1.1](http://www.codetrax.org/versions/217) - Bug fix: In 1.1.0 two new filters had been added with wrong prefix in their names. This has been fixed in 1.1.1. - [1.1.0](http://www.codetrax.org/versions/212) - [1.0.5](http://www.codetrax.org/versions/211) - [1.0.4](http://www.codetrax.org/versions/210) - [1.0.3](http://www.codetrax.org/versions/209) - [1.0.2](http://www.codetrax.org/versions/208) - [1.0.1](http://www.codetrax.org/versions/203)