=== WP-Optimize - Clean, Compress, Cache. ===  
Contributors: DavidAnderson, ruhanirabin, DNutbourne, aporter, snightingale, lumberhack
Donate link: https://david.dw-perspective.org.uk/donate
Tags: cache, optimizing, database, image optimize, performance, clean, spam, speed, caching, smush, smushing
Requires at least: 3.8
Tested up to: 5.3
Stable tag: 3.0.13
License: GPLv2+
License URI: https://www.gnu.org/licenses/gpl-2.0.html

WP-Optimize makes your site fast and efficient. It cleans the database, compresses images and caches pages. Fast sites attract more traffic and users.

== Description ==

WP-Optimize is a revolutionary, all-in-one plugin that cleans your database, compresses your images and caches your site. 

Our cache feature is built around the world’s fastest caching engine. This simple, popular and highly effective tool has everything you need to keep your website fast and thoroughly optimized!

[vimeo https://vimeo.com/333705073]

It does it in three clever ways: 

* It allows you to clean and optimise your database.
* It gives you the option to compress your images.
* It allows you cache your pages, for super fast load times (read more caching information below).

Extensive tests show the cache feature alone can make WordPress sites faster than any other caching plugin available.  But when you combine the cache with the database and image optimize features, the difference with alternative solutions is significant.

= 1. Cleans the database  =

Your WordPress database stores everything that you need for your website – plus many things that you don’t. WP-Optimize clears out all of this unnecessary data, cleans up your tables and even retrieves space lost to data fragmentation.

Mobile-friendly and incredibly simple to use, it:

* Removes all unnecessary data (e.g. trashed/unapproved/spam comments, stale data) plus pingbacks, trackbacks and expired transient options
* Compacts/de-fragment MySQL tables with a button-press
* Detailed control of which optimizations you wish to carry out
* Carries out automatic weekly (or otherwise) clean-ups
* Retains a set number of weeks’ data during clean-ups
* Performs optimizations without the need for running manual queries
* Automatically trigger a pre-optimize backup via <a href="https://updraftplus.com">UpdraftPlus</a>
* Show database statistics and potential savings

<strong>Why is this important?</strong>

* The tables in MySQL (the database that WordPress uses) will, over time, become inefficient as data is added, removed, moved around. Asking MySQL to optimize its tables every now and again will keep your site running as fast as possible. It won’t happen by itself.
* Every-time you save a new post or pages, WordPress creates a revision of that post or page. If you edit a post 6 times you might have 5 copy of that post as revisions. This quickly adds lots of rarely-used data to your database tables, making them unnecessarily bloated, and slower to access.
* There might be thousands of spam and un-approved comments in your comments table, WP-Optimize can clean and remove those in a single click.
* WP-Optimize reports which database tables have overhead and wasted spaces also it allows you to shrink and get rid of those wasted spaces.
* Automatically cleans your database every week and respects the “Keep last [selected number] weeks data” option.


= WP-Optimize helps you to: =

* <strong>Make space:</strong> When you edit a post or page on your website, WordPress automatically saves the new revision to the database. If you edit things a few times (and particularly if the post is long), your database soon gets clogged up with old revisions that just sit there, taking up valuable space. WP-Optimize removes these unnecessary post revisions, freeing up valuable Megabytes of data and increasing speed and efficiency. It also cleans up your comments table, removing all the spam and un-approved comments that have built up with a single click.

* <strong>Take control:</strong> WP-Optimize reports on exactly which of your database tables have overhead and wasted space, giving you the insight, control and power to keep your website neat, fast and efficient.

* <strong>Keep it clean and fast:</strong> Once enabled, WP-Optimize can run an automatic clean-up on a schedule, keeping a selected number of weeks’ data, according to your specification.

= 2. Compresses images =

Loading large images is often the biggest culprit in slowing your site’s loading time.  

WP-Optimize also has an image-compression tool that uses cutting-edge lossy compression techniques to convert large images (which take a long time to load up) into compressed files saved in your image library, where they can be uploaded in an instant. 

It enables you to compress PNG, JPG, GIF, BMP and TIF pictures up to 5MG in size, and it’s packed with other useful features, including:

* <strong>Bulk compression</strong>, allowing you to compress multiple existing images at the same time.
* <strong>Intelligent, multi-pass lossy compression algorithm</strong>, which gives you twice the compression with much less loss of resolution.
* <strong>‘Restore Originals’ function</strong>, which allows you to retrieve or revert back to your original images at any point.
* <strong>Auto-compress function</strong>, which automatically compress images as they’re added to the site. 
* <strong>EXIF Data-Keeping</strong> means image information is retained even once the image is compressed.
* <strong>‘Compress Big Files function’</strong> allowing you to compress images up to 64MB- much higher than any other plugin.

Smaller yet high quality images means significantly faster page loading times and frees up server space and bandwidth for more customers.

= 3. Caches pages =

<strong>Page caching is probably what will make the biggest difference to your website's performance. </strong>

Caching involves keeping dynamic data in a temporary storage area so that it can be retrieved in an instant. Caching is a sure-fire way to ensure that web pages load at lightning-fast speed.

Practically, our powerful yet simple cache feature generates the cache when a visitor visits any page or post on your site. WordPress processes the dynamic php files to generate that page, and we save it into a static html file in the cache folder, so that when the next user visits, the page is cached and doesn't need processing. This caching results in a much faster loading time, and  gives a slight break to your server. So caching increases speed and performance while reducing the server's use of resources.

With minimal configuration, caching your site with WP-Optimize is easy to do thanks to a load of useful features, including:

* <strong>Cache preloading</strong> to ensure the cache is always ready and loaded.
* <strong>Gzip compression</strong> of HTML, JavaScript, and CSS to reduce site load time.
* <strong>Device-Specific cache</strong> to ensure the optimized page version is always served.
* <strong>Advanced cache exclusion rules</strong>, so that you can cache almost anything by excluding logged in users, specific URLs or cookies.
* <strong>Browser Cache</strong> to instruct client browsers to reuse cached resources (HTML, CSS, JS) if no changes were made since the last request. 

Overall WP-Optimize brings the best cache and optimization technology together in a single seamless plugin to make your WordPress site fast, lean and efficient.

= WP-Optimize Premium =

Our free version of WP-Optimize is great, but we also have an even more powerful Premium version with extra features that offer the ultimate in freedom and flexibility:

* <strong>Multisite Support:</strong> extends database optimisations so they function for multiple WordPress sites at a time. If you manage more than one website, you will need WP-Optimize Premium.
* <strong>Flexibility and Control:</strong> gives you the power to optimize select individual tables or a particular combination of tables on one or more WordPress websites, rather than having to optimize all database tables.
* <strong>Deleting unused and unwanted images:</strong> removes orphaned images from your WordPress site, plus images of a certain, pre-defined size.
* <strong>Sophisticated Scheduling:</strong> offers a wide range of options for scheduling automatic optimization. Specify an exact time and run clean-ups daily, weekly, fortnightly or monthly and perform any number of additional once off optimizations.
* <strong>Seamless Graphical User Interface:</strong> for superb clarity in scheduling and managing of multi-site optimizations.
* <strong>WP-CLI support:</strong> provides a way to manage optimizations from command-line interface if you have lots of sites
* <strong>Lazy Loading:</strong> load only the images and part of a web-page when it is visible to the user so they can see something very quickly.
* <strong>Optimization Preview:</strong> gives users the ability to preview, select and remove data and records available for optimization from the database.
* <strong>Premium support</strong> - caching is one of the most complex things you can do for a website, so premium support offers you peace of mind there’s someone to talk quickly to if you need any technical answers or help configuring the optimizations or cache settings for your website.

= Translations =

Translators are welcome to contribute to the plugin. Please use the [WordPress translation website](https://translate.wordpress.org/projects/wp-plugins/wp-optimize).

== Installation ==

There are 3 different ways to install WP-Optimize, as with any other wordpress.org plugin.

= Using the WordPress dashboard =

1. Navigate to the 'Add New' in the plugins dashboard
2. Search for 'WP-Optimize'
3. Click 'Install Now'
4. Activate the plugin on the Plugin dashboard

= Uploading in WordPress Dashboard =

1. Download the latest version of this plugin from https://wordpress.org/plugins/wp-optimize/
2. Navigate to the 'Add New' in the plugins dashboard
3. Navigate to the 'Upload' area
4. Select the zip file (from step 1.) from your computer
5. Click 'Install Now'
6. Activate the plugin in the Plugin dashboard

= Using FTP =

1. Download the latest version of this plugin from https://wordpress.org/plugins/wp-optimize/
2. Unzip the zip file, which will extract the wp-optimize directory to your computer
3. Upload the wp-optimize directory to the /wp-content/plugins/ directory in your web space
4. Activate the plugin in the Plugin dashboard

== Frequently Asked Questions ==

= Isn't it better to use a dedicated caching plugin to cache my site? =

We've built WP-Optimize around the most advanced and powerful caching technology. Our caching tests and feedback from real-world users show that the caching feature alone can make your site faster than any other cache plugin or optimization. <a href="https://ps.w.org/wp-optimize/assets/screenshot-1.png?rev=2125386">See these speed test results.</a>

= Is optimizing my database safe? =
Yes; optimizing does not involve any "tricks" or poking around in dangerous ways. It involves running routine clean-up operations using well-defined, common MySQL commands. <strong>Nevertheless, we always recommend backups</strong>, which cover every possibility; not just database malfunctions, but hackers, human errors, etc. We recommend <a href="https://wordpress.org/plugins/updraftplus/">UpdraftPlus</a>.

= What savings can I expect to make? =
This is a "how long is string?" sort of question. It depends completely on your site - how big it is, how many users interact on it, how long it has been running, and when you last optimised it. However, the savings and speed-ups can be substantial; it is always worth making sure that your database is optimised.

= How do I get support? =
In our support forum, here: https://wordpress.org/support/plugin/wp-optimize/

= WP-Optimize does not make large savings on my database =
This is rare; it’s probably because you’re with a shared web hosting company that doesn’t allow scripts to run an optimize command via SQL statements (SQL "OPTIMIZE" instruction). Please consult your web hosting company on this matter.

= Is the plugin tried and tested? =
Yes - WP-Optimize is WordPress's #1 most-installed optimisation plugin, with over 800,000 users and a pedigree going back over 8 years.

= Does WP-Optimize support InnoDB tables? =
WP-Optimize will disable some features if it detects InnoDB tables. Optimization of the database tables on-disk is not available, but other clean up features would work.

= Can you help me restore my database? =
Not unless you have an existing backup. Please ensure that you make a backup of your entire database before using WP-Optimize for the first time, and when you upgrade to a major new version of it. We recommend <a href="https://wordpress.org/plugins/updraftplus/">UpdraftPlus</a>.

= Are there any bugs in this plugin? =
The plugin is an ongoing work; that means that it is impossible to rule out unforeseen situations and bugs. So I would recommend you to test it out on your local system or make a backup of your database (just to be extra careful).

= How do I stop transient options from coming back automatically each time I clear them? =
When WordPress uses a particular transient, that specific transient is re-created automatically. So, it's normally for ones which are in active use to gradually re-appear. The best way to keep things optimal is to clear the transient options on a scheduled basis. For example, WordPress may create 50 transient option in a week. If you schedule WP-Optimize to clear these options on a weekly basis, you’ll have far fewer building up.

= The table size shows wrong / Not optimizing  =
Please check your database for corrupted tables. That can happen, usually your web hosting company can run the repair command on the db.

= Which WordPress and PHP versions are supported? =
To use all features in the plugin, a minimum of version WordPress 4 with PHP 5.3 are required. But we do recommend to use the latest version of WordPress. Using PHP 7+ is also highly recommended, as our caching feature will work even faster.

= Which optimisation will make the biggest difference? =
This depends on your setup (theme, number and quality of plugins used, etc...), but generally, caching will make the biggest visible difference to your website's performance. Indeed, the cache functionality bypasses most of WordPress code to serve your pre-optimised cached pages directly to your visitor, significantly increasing the speed.

= What is caching, or page caching? =
<em>"Caching", from Wikipedia:</em> "In computing, a cache is a hardware or software component that stores data so that future requests for that data can be served faster; the data stored in a cache might be the result of an earlier computation or a copy of data stored elsewhere. A cache hit occurs when the requested data can be found in a cache, while a cache miss occurs when it cannot." — WP-Optimize cache does this by saving the page computed by WordPress on the disk. When a user visits a page, WP-Optimize will serve the cached page before WordPress is loaded. If the page wasn't cached before, it will be computed by WordPress, and WP-Optimize will then save the result to the cache.

= Why should I use a caching plugin on my website? =
You think your site is fast without caching? A caching plugin will make your website even faster. A faster cached website will increase SEO, it will improve your visitors experience. Caching will also save your server's resources.

= Is the WP-Optimize page cache compatible with Gutenberg and WordPress 5.0+? =
Yes, your Gutenberg pages will be cached, as well as those created with page builder plugins such as Elementor.

= How do I know my webpage is being cached (or why it isn’t)? =
If cache is enabled, and in order to see if your page is cached, use the “View Source” function in your web browser to view the page source. To find caching information, scroll down to the bottom, and you should see a line added by the cache: `<!-- Cached by WP Optimize - https://getwpo.com - Last modified: Sat, 20 Jul 2019 21:17:19 GMT ->`
However, note that if you are using a further service that minifies HTML (e.g. Cloudflare), then this line may have been removed. Another method is to inspect the contents of the directory wpo-cache inside your wp-content directory. <a href="https://getwpo.com/faqs/how-do-i-know-my-webpage-is-being-cached/>Further information can be read here</a>
Also note that if you do not preload the cache, a page or post will have to be visited once for the cache file to be generated.

= How do I configure the page cache? =
Go to WP-Optimize -> Cache and enable caching. For most people, that will be enough. If you run an e-commerce, have a custom login page or any page that has dynamic content, you might want to exclude certain urls from the cache. See <a href="https://getwpo.com/documentation/">Advanced caching options</a> in our cache documentation to know more on excluding an URL from the cache.

= Is the caching feature compatible with e-commerce plugins? =
Yes, caching with WP-Optimize allows you to safely cache your products, with plugins like WooCommerce or Easy Digital Downloads, or any e-commerce that uses `DONOTCACHEPAGE` to exclude sensitive pages from caching (e.g. my account, cart or checkout pages).

= Do I need a special setup to use the caching feature? =
No, if WordPress works properly, WP-Optimize will be able to cache your pages and posts.

= Can I use the page caching feature together with another cache plugin? =
No, because both cache plugins would need to use the drop-in plugin `advanced-cache.php`. If you turn off caching on WP-Optimize, you can use any other caching plugin and still use the other features of WP-Optimize. But we do recommend using our caching solution.

= Is WP-Optimize caching compatible with Cloudflare? =
Yes! No special cache configuration is needed. Page caching on the WP site (that done by WP-Optimize) is independent of proxy cacheing (e.g. Cloudflare) – you can use both, or neither, and they will complement each other and not interfere. <br>Just one thing to note – Cloudflare will strip out the special HTML comment at the bottom of the source of a page that is helpful to confirm that page caching is working, so, don’t be confused by that – it’s absence doesn’t indicate the cache is not working.

= Can I empty the cache automatically when performing a custom action? =
Yes, you can trigger a cache purge action using WP-Optimize public functions. If you want to clear the whole cache, use the function `wpo_cache_flush()`. If you want to clear the cache files for a specific page or post, use `WPO_Page_Cache::delete_single_post_cache($post_id);`. Those cache options are available after WP action `plugins_loaded`.

= Will the comments work even when page caching is enabled? =
Yes, when using WordPress' commenting system, your users will still be able to post comments. Every time a comment is approved, the cache for that page or post will be cleared, allowing the next visitor to see an up to date list of comments.

= What is "cache preloading"? =
Usually, a page is cached when a user visits it. So the first user visiting won't be served a cached version of the page, and will wait longer than the next users. The cache preloading functionality will go through all your pages and posts, and simulate a visit by a user, allowing WP-Optimize to cache the pages before anyone visits them. Your first visitor will thus be served a cached version of the page, increasing its performance.

= What frequency should I choose for the cache preloading schedule? =
Choosing a frequency for the cache preloading schedule will depend on factors such as the frequency at which the website content is updated, the number of pages in the cache, the resources of the server and more. 
For example a site with hundreds of pages will require more resources to preload its cache. So choosing a high frequency will mean that the cache will be recreated often, and the resource usage will be higher.
On a website where updates aren't as frequent, you can even disable the cache preloading schedule, or set a high cache lifespan and set the cache preloading schedule to follow it.

= How do I cache only the home page? =
Add /.+ to the cache option “URLs to exclude from cache” on the advanced settings tab.

= How do I prevent WP-Optimize from caching a certain page =
To prevent a page from being cached, you can add the URL to the field “URLs to exclude from cache” in the cache “Advanced settings” tab. If you are developing a plugin and want to prevent a page from being cached, you can define the “DONOTCACHEPAGE” constant on the pages you need. Any request where “DONOTCACHEPAGE” is defined will not be cached.

= Is the caching feature of WP-Optimize free? =
Yes the caching feature is free. You will always be able to cache your website for free using WP-Optimize and we are constantly working on improving the existing cache feature. We will add more caching options to the free version and develop more specific caching options in the premium version to enable you to taylor the caching functionality to your needs.

= Where does WP-Optimize store the cached files? =
The cached files are stored in the common “wp-content/cache” folder, inside a “wpo-cache” folder. Removing the “cache” folder will delete all of WP-Optimize's cache, as well as those from other plugins.
Deleting the "cache" folder is generally safe, as those cached files will be regenerated.

= How do I disable caching? =
Go to WP-Optimize settings > Cache and toggle the “Enable page caching” option to on/off.

= Will caching slow down my server? =
No, caching will actually reduce the load on your server, by reducing the amount of PHP and mysql used. You might see a peak in resource usage when using the cache preloader, as this functionality will create the cache files for all your pages in a short amount of time. But once this is done, performance should increase and the load on your server will decrease. Every single major site uses caching to serve cached pages faster by using fewer resources. 

= Can I make certain parts of the page stay dynamic when cache is enabled? =
The cached page is sent to the user before most of WordPress was loaded. The plugins aren't loaded yet, making it impossible for them to change the cached content at every request.
So at the moment if you want to keep parts of your page dynamic (e.g. adverts, widgets, shopping cart...) AND keep it cached, you will have to use custom solutions using javascript and AJAX to fetch those dynamic parts from the server.

= How do I delete the WP_CACHE define from wp-config.php? =
WP-Optimize will remove the “WP_CACHE” constant from wp-config.php when you disable page caching, or when you deactivate the cache plugin. If you need to remove it manually, you can use FTP to edit wp-config.php and delete the line define ('WP_CACHE', true );
If page caching is still enabled in the settings, WP-Optimize will attempt to add the line again, as it is required for the caching functionality to work. 

= My filesystem is not writable to increase security. What do I need to do to make it compatible with the caching functionality? =
WP-Optimize caching feature needs write access to the ‘wp-content/cache’ folder, as this is where the cache files will be stored. It also needs to define the constant ‘WP_CACHE’ in ‘wp-config.php’, it will need access once to ‘wp-content/advanced-cache.php’, as well as to the folder ‘wp-content/wpo-cache’ to write the cache settings. 

= How do I change file permissions? =
If you need to change file permissions to enable caching, you can follow the instructions on this page https://wordpress.org/support/article/changing-file-permissions/

= What is the maximum number of pages I can cache? =
There is no limit to the number of pages you can cache. The only limit is the space on your server and the maximum number of subdirectories allowed by your server, as caching will write files in subdirectories following the permalink structure.
If you were to reach a caching limit, it probably means that your server is not fit for the size of your website and caching needs.

= How do I serve cached pages to people using a phone or tablet? =
You can generate a separate cache by selecting ”Generate separate files for mobile devices” in the page cache settings. This cache setting is only necessary if you use a specific theme for mobile devices, or for certain AMP plugins.

= Does WP-Optimize cache work with Nginx? =
Yes, the cache feature works with Nginx. Should you want to enable browser caching or GZIP compression, you will have to do this yourself directly on the server settings.

= Does caching work with Windows Server (IIS) ? =
Yes, the cache feature works with IIS. As with Nginx, if you need to enable browser caching or GZIP compression, you will have to do this yourself on the server.

= Does the WP-Optimize page cache work with non-pretty (query parameter-based) permalinks? =
No. It’s necessary to have pretty permalinks of the type http://xxxxx.com/my-post/ rather than http://xxxxx.com/?p=1234 for cache to work. Pretty permalinks are the WordPress default setting, and there is no good reason to turn them off, so you should not have a problem with this.
Note that cache will work with permalinks including /index.php/. It is only those based upon query parameters (?…) where cache won't work.

= When does WP-Optimize clear the page cache? =
* When you publish new content or update/edit existing content, the cache for that post/page will be cleared.
* Changing/updating current themes and parent themes (of child themes) will purge the cache.
* When turning off the cache feature in WP-Optimize

= Will pages in the WP admin dashboard be cached? =
No, WP dashboard pages are not cached. The cache functionality is only meant to cache frontend pages.

= What is cache lifespan? =
The cache lifespan is the time a cached file will be kept before being regenerated.
One of the main reason for setting a lifespan to your cache is that some plugins and themes use nonces, which are printed in the source code of the page (<a href="https://developer.wordpress.org/plugins/security/nonces/">Read more about nonces here</a>). These nonces cannot be reused and are valid for 12 hours by default (developers can change that value). The cache plugin will store the nonce in the page, and this one will become invalid after that perdiod of time, which can affect certain functionalities of your plugins and themes. Setting a cache lifespan to under 10 hours ensures the cache is flushed automatically before the nonce expires. This way you can use WP-Optimize's cache feature on sites which use nonces.
An other reason is that you may want your pages to reflect some changes without having to clear the whole cache. Indeed if you have many pages and posts, you might not want to clear every cache file with every change, but rather set an interval at which they will expire and be regenerated.

= What value should the cache lifespan be? =
A lower cache lifespan value will result in more frequent cache update activity on your server, and thus more preload processes, if activated. 
If your site does not use nonces, and your site's cache doesn't need to be updated often, you can set the cache lifespan to a high value or to 0 to give it an infinite lifespan.
The cache lifespan option is set to 10 hours by default, but you may go down to 8 or even less. 
If you notice any issues due to high server load, set a higher interval for the preloader.

== Screenshots ==

1. Cache - plugins comparison benchmark
2. Database optimization
3. UpdraftPlus running a backup before an optimization proceeds
4. Table Report
5. Image compression
6. Main cache screen
7. Settings
8. Real world tests show the cache feature alone can make your site faster than any other caching plugin
9. Features comparison

== Changelog ==

= 3.0.13 - 21/Oct/2019 =

* FIX: Don't show VIEWs as corrupted database tables
* TWEAK: Image compression - Cancel button now stops the compression process
* TWEAK: Only show general notice when update notice isn't shown
* TWEAK: Improve message when Gzip compression is already enabled
* TWEAK: Premium - Use path to include lazy load script
* TWEAK: Image compression - Use wp_remote_get() instead file_get_contents() for retrieving compressed images
* TWEAK: Use wp_remote_get() instead file_get_contents() for retrieving compressed images
* TWEAK: Cache feature - add a 'Purge all' cache button to the admin bar
* TWEAK: Premium - Prevent php warning in scheduled optimisations list
* TWEAK: Premium - Unused images feature - Add compatibility with Advanced Custom Fields (ACF) image and gallery fields

= 3.0.12 - 24/Sep/2019 =

* TWEAK: Cache - Purge cache files when updating menu, saving the customizer and editing widgets
* TWEAK: Cache - Do not show the reason for not caching when the request is DOING_CRON
* TWEAK: Premium - Unused images feature - Improved detection on sites with many posts/images
* TWEAK: Automatically delete smush image backups option
* TWEAK: Premium - Unused images feature - Better detection of featured images
* TWEAK: Cache - Ability to purge single page or post from cache
* TWEAK: Cache - Display the content of advanced-cache.php to the user if it was not writable when enabling cache
* TWEAK: Image compression - Automatically delete image backups option
* TWEAK: Image compression - metabox now inherits the settings from the main screen
* TWEAK: Image compression - Added feature to mark images as already compressed by another tool
* TWEAK: Image compression - Added detailed log information when image compression fails.
* TWEAK: Premium - Unused images feature - Improved detection on sites with many posts/images
* TWEAK: Premium - Unused images feature - Better detection of featured images
* TWEAK: Premium - Lazy load - Added WooCommerce support
* TWEAK: Premium - Increased warning level and visibility when deleting unused database tables and unused images
* TWEAK: Prevent a couple of unwanted PHP notices being logged when running cron via the command-line
* TWEAK: Tweaked update notice wording

= 3.0.11 - 07/Aug/2019 =

* FIX: Check the results of opendir() when emptying the cache, to prevent a possible infinite loop if it fails
* FIX: Compatibility issues with WordPress 4.0
* FIX: Replace function that did not exist on PHP 5.2
* TWEAK: Add work-around for plugins which call the WP action comment_post incorrectly
* TWEAK: Change the algorithm for locating file-based-page-cache.php to handle same-server site moves better
* TWEAK: Prevent an unwanted PHP notice caused by Action Scheduler purges

= 3.0.10 - 30/Jul/2019 =

* TWEAK: If short-circuiting the attachment_fields_to_edit filter result, return the pre-existing value
* TWEAK: Adjust wpo_delete_files() and related functions with extra sanity checks

= 3.0.9 - 30/Jul/2019 =

* FIX: Fix bug in logic for sending "Content-Encoding: gzip" header that could cause it to be sent prematurely with non-cached pages

= 3.0.8 - 30/Jul/2019 =

* FIX: Lazy-loading regression in recent Premium release
* FIX: Smush images selection on multisite
* FIX: Displaying WP-Optimize tabs menu on mobile devices
* TWEAK: Disable redundant lazy-loading feature when Divi theme is active
* TWEAK: Improve accuracy of message shown when it is not possible to automatically enable Gzip compression of static resources
* TWEAK: Only output reasons a page was not cached if the wp_footer action was run

= 3.0.7 - 25/Jul/2019 =

* FIX: Fix some logic bugs related to the decision whether to send gzip-encoded cached content
* FEATURE: To aid debugging if WP_DEBUG is turned on then if a page was *not* cached, then the HTML source will now contain the reason(s) why not in the footer
* TWEAK: The is_user_logged_in() function is not necessarily available during a WP 'technical difficulties' scenario
* TWEAK: Purge site homepage cache after updating post or publishing a new post (can be over-ridden with the filter wpo_delete_cached_homepage_on_post_update)

= 3.0.6 - 25/Jul/2019 =

* FIX: Regression causing incorrect JavaScript filenames in the Premium release in 3.0.5
* TWEAK: Also add cache-busting for the compiled handlebars file
* TWEAK: Change the handlebars enqueue handle to prevent double loading

= 3.0.5 - 23/Jul/2019 =

* FIX: Short-circuit Updraft_Smush_Manager::add_compress_button_to_media_modal() outside of a dashboard context, so that plugins or themes that hook into some dashboard hooks outside of that context can't cause fatal errors
* TWEAK: Added suffixes with WP-Optimize version number to js, css files
* TWEAK: Change the method used to generate the configuration file path in advanced-cache.php; no issues were reported, but analysis indicated a potential way to generate a path that would not agree with what was written by saving settings; and also another way to generate an invalid path on Windows webservers running on non-standard ports.
* TWEAK: Use WPO_CACHE_CONFIG_DIR constant instead string value in advanced-cache.php

= 3.0.4 - 20/Jul/2019 =

* FIX: Fixed a regression in 3.0 with orphaned relationship data optimization

= 3.0.3 - 20/Jul/2019 =

* TWEAK: Prevent saving of page cache settings when the page cache was already off and another page cache plugin was active from over-writing the other plugin's advanced-cache.php

= 3.0.2 - 19/Jul/2019 =

* TWEAK: Rename in order to cache-bust sites that cached old versions of the JS admin scripts
* TWEAK: Prevent unwanted PHP notice if saving page cache settings without ever having turned the cache on

= 3.0.1 - 18/Jul/2019 =

* FIX: Prevent a potential stray line of text appearing

= 3.0.0 - 17/Jul/2019 =

* FEATURE: Adds a caching feature, with page cache, browser cache control and gzip control
* TWEAK: Smush feature added to medial modal
* TWEAK: Remove references to Keyy
* TWEAK: Image compression metabox tweaks
* TWEAK: Preload after purging, If preload schedule is enabled
* TWEAK: Prevent image compression AJAX call from firing upon every tab change
* TWEAK: Load assets in admin_enqueue_scripts()
* TWEAK: Smush all image sizes
* TWEAK: Add quick feedback link
* TWEAK: Delete the original backup file when an attachment file has been deleted
* TWEAK: Remove die() from shutdown handler
* TWEAK: Remove references to Keyy

= 2.3.4 - 10/Jun/2019 =

* FIX: Incorrect file paths on multisites 
* FIX: Wrong DB Schema caused image compression to fail on multisites
* TWEAK: Improve image compression UI
* TWEAK: Add the possibility to hide the image optimisation metabox in the media edit screen.
* TWEAK: Fix potential PHP notice in task queue when Automatic Smush is activated
* TWEAK: Improve JSON-reparser to cope with even more exotic junk from some setups with problems elsewhere in their stack
* TWEAK: Remove the numerical index column from the list of tables
* TWEAK: Prevent methods being called when create_task returns false
* TWEAK: Prevent PHP log warnings when images are missing from server (log in WP-O internal log instead)
* TWEAK: Changed the default settings page from 'Settings' to 'Database'
* TWEAK: Better discoverability of Premium features
* TWEAK: Use new task manager class Updraft_Task_Manager_1_1

= 2.3.3 - 17/Apr/2019 =

* FIX: Revert faulty change to the default settings page in 2.3.2, which prevented optimization buttons working

= 2.3.2 - 17/Apr/2019 =

* FIX: Non-ASCII filenames could get mangled in the image optimization preview, resulting in images not shown (and WP 404 generation on the back-end).
* FIX: Optimizing a table now runs correctly after automatic pre-optimize backup
* TWEAK: Changed the default settings page from 'Settings' to 'Database'
* TWEAK: Updated plugin links

= 2.3.1 - 16/Apr/2019 =

* FIX: Fix a code path that could cause a fatal error on PHP 5.2
* TWEAK: Optimizing a table should then refresh the information in the UI shown for it
* TWEAK: Use an image compression logfile path inside the uploads hierarchy, with unpredictable salted element

= 2.3.0 - 12/Apr/2019 =

* FEATURE: Compress images using lossy and lossless compression - both existing images, and newly uploaded
* FIX: Wrong information about corrupted tables
* TWEAK: Prevent PHP notices on calls from UpdraftCentral
* TWEAK: Prevent notices about Premium showing in Premium, correct button text, update coupon
* TWEAK: Prevent the overdue cron checker running twice instead of once

= 2.2.13 - 04/Mar/2019 =

* FIX: Fixed RTL layout
* FIX: Detect more relationships between tables and plugins in orphaned database tables optimization
* FIX: Fixed orphaned relationships optimization
* TWEAK: The informational list of WP core tables missed some possible extra tables on multisite

= 2.2.12 - 07/Feb/2019 =

* TWEAK: Updated information on More plugins tab
* TWEAK: Fix header layout when a system or third party notification are shown
* TWEAK: (Premium) Fix layout in unused images list mode
* TWEAK: Improve data reliability in javascript
* TWEAK: Improve orphaned relationships data optimization
* TWEAK: Wrong message for "remove spam and trashed comments" optimization
* TWEAK: Output additional information if table was not deleted
* FIX: Added escaping for table names in database queries
* FIX: Fix another possible fatal error due to missing get_plugins() function
* FIX: Improve identification of installed/active plugins

= 2.2.11 - 16/Jan/2019 =

* FIX: A regression in the "identify table by owner" feature caused optimizing to silently fail on some tables
* TWEAK: Added ability to exclude lazy load images by class

= 2.2.10 - 11/Jan/2019 =

* FEATURE: Added the ability to download unused images list (Premium version) as a CSV file
* FIX: Load scripts and styles only on WP-Optimize pages
* FIX: Fix a possible fatal error due to missing get_plugins() function
* TWEAK: Remember selected optimizations on Database page
* TWEAK: Prevent PHP notices when saving settings or optimizing in some circumstances

= 2.2.9 - 03/Jan/2019 =

* FIX: Change a newly-introduced fragment that was not compatible with PHP 5.2
* TWEAK: Tweak some other code that had PHP 5.2 compatibility issues

= 2.2.7 - 31/December/2018 =

* RE-FACTOR: Refactoring and reorganisation of the UI
* TWEAK: Added feature to view unused images as list
* TWEAK: Fix sorting sizes columns in Tables information to take into account textual modifiers
* FIX: MetaSlider images detected as unused
* FIX: Preview for Trashed posts optimization doesn't work
* FIX: Unselected optimizations could be run on a scheduled run

= 2.2.6 - 30/October/2018 =

* FEATURE: Added Gzip compression support
* FIX: Unexpected content in the footer after preview popup closed
* TWEAK: Mark as supporting WordPress 5.0
* TWEAK: Update seasonal notices
* TWEAK: Removed redundant checkbox for Lazy Loading settings
* FEATURE: Remove orphaned database tables, and identify (many) known tables by plugin.

= 2.2.5 - 24/August/2018 =

* FEATURE: Preview data before deleting. (Premium)
* FEATURE: Lazy Loading for images, iframes and videos. (Premium)
* FEATURE: Added custom capabilities wpo_prevent_run_optimizations and wpo_prevent_manage_options (Premium)
* FIX: Correct tables order sorting
* FIX: Wrong numbers in total cleaned field
* FIX: Don't show incorrect overhead value if option innodb_file_per_table disabled
* TWEAK: Added option to clean "all" transient options and network-wide transient options for multisite WordPress installation
* TWEAK: Links to UpdraftPlus automatically Install/Activate UpdraftPlus plugin
* TWEAK: FAQ links point to getwpo.com
* TWEAK: Auto-draft, revision posts and pingback comments removing with their meta data
* TWEAK: Scheduler is not using the WordPress timezone settings
* TWEAK: Detecting corrupted tables in background.
* TWEAK: Unused Images optimization correctly detects images in pages built with popular plugins - Page Builder by SiteOrigin, Visual Composer, Beaver Builder, Elementor.
* TWEAK: Paginate unused images
* TWEAK: Added checkbox for select all optimizations
* TWEAK: Prevent deleting homepage images in image optimization
* TWEAK: Override the default multisite site list fetch limit of 100 sites

= 2.2.4 - 07/May/2018 =

* TWEAK: Changed the term 'Automatic' to 'Scheduled'.
* TWEAK: Show correct table type for views
* TWEAK: Fixed string spelling and syntax errors
* TWEAK: Disabled Simple History logging option if plugin is not installed.
* TWEAK: Prevented PHP notices in repair tables functionality

= 2.2.3 - 04/Apr/2018 =

* FEATURE: Added the ability to repair corrupted database tables
* FIX: Fixed dismiss notices functionality
* FIX: When detecting potentially unused images, exclude those found mentioned in the options table(s)
* TWEAK: Load WPO translations (logger classes info included) when template is pulled for UpdraftCentral-WPO module
* TWEAK: Add get_js_translation command for the UpdraftCentral WPO module
* TWEAK: Added logging for fatal errors

= 2.2.2 - 28/Feb/2018 =

* TWEAK: Prevent possible PHP notice when parsing logger options

= 2.2.1 - 28/Feb/2018 =

* FIX: Fix number counting in Table information tab
* FIX: Fix InnoDB optimization UI
* TWEAK: Removed orphaned attachment optimization from optimizations UI list

= 2.2.0 - 19/Feb/2018 =

* FEATURE: Added the ability to export/import WP-Optimize settings
* FEATURE: Extended the logging class to include logging for Simple History Logger, Slack, Email, syslog and a simple 'ring' log
* FEATURE: Added the ability to optimize ARCHIVE and Aria (MariaDB) database tables.
* FEATURE: Added the ability to sort data in the "Table Information" tab
* FEATURE: Added the ability to search tables in "Table Information" tab
* FEATURE: Added the ability to optimize an individual table. (Premium)
* FEATURE: Added the ability to optimize multisites. (Premium)
* FEATURE: Allow the user to create arbitrarily complex automatic optimization schedules (Premium)
* FEATURE: Added ability to use WP CLI interface for run optimizations. (Premium)
* FIX: Auto clean-up settings not optimizing database tables
* FIX: Comments count after related to comments optimization
* FIX: Fix unapproved comments count
* TWEAK: Add functions to pull WP-Optimize templates for UpdraftCentral
* TWEAK: Allow user to tick the "Take a backup with UpdraftPlus before optimizing" option from UpdraftCentral
* TWEAK: Show last automatic optimization time using site's configured timezone and locale
* TWEAK: Extra MySQL and MariaDB checks for optimization, along with an over-ride functionality.
* TWEAK: updated previous optimizations and added optimizations for trash posts, trash comments and orphaned attachements
* TWEAK: Use higher-quality spinner image
* TWEAK: Adjusted notices about other products
* TWEAK: Added message for multisite users with proposal to upgrade to Premium.
* TWEAK: Optimize the check for whether both free and Premium are installed
* TWEAK: Added Premium / Plugin Family tab
* TWEAK: Added seasonal dashboard notices  

= 2.1.1 - 28/Feb/2017 =

* FEATURE: Added the ability to take a automatic backup with UpdraftPlus (https://updraftplus.com) before an optimization
* FEATURE: When optimizing from the dashboard, tables are now optimized one by one, to reduce the scope for timeouts
* FIX: Removal of sitemeta items from main site on multisite install was not proceeding
* TWEAK: Adding premium bootstrapping to WP-Optimize for adding premium features in the future
* TWEAK: A few wording tweaks, plus automatically refresh the page if the 'admin bar menu' option is changed
* TWEAK: Introduce internal logging API

= 2.1.0 - 28/Dec/2016 =

* FOCUS: This release concentrates upon the user-interface, and in particular upon improving the clarity of each part, and making optimizations, saves and other actions possible without page reloads.
* FEATURE: Any optimisation can now be run individually with a single button press
* TWEAK: All optimisations run via the dashboard page are now run via AJAX (no page refresh)
* TWEAK: Settings saving now takes place via AJAX (no page refresh)
* TWEAK: Navigation between different tabs now takes place without a page refresh
* TWEAK: The "trackback/comments" actions section now operates via AJAX (no page refresh needed)
* TWEAK: "Refresh" button in the "Status" widget now refreshes via AJAX (no page refresh needed)
* TWEAK: When saving settings or running an optimization, the "Status" widget now automatically refreshes
* TWEAK: Make the admin bar menu into a drop-down, making it quicker to access individual tabs
* TWEAK: Call set_time_limit to reduce the chances of PHP self-terminating via reaching max_execution_time
* TWEAK: Introduce dashboard notice infrastructure
* TWEAK: The lines showing information on how many spam/trashed posts and comments existed were incomplete

= 2.0.1 - 12/Dec/2016 =

* OWNERSHIP: WP-Optimize is now under the leadership of Team UpdraftPlus - https://updraftplus.com. A big thank you to Ruhani (who remains on-board) for his leadership of WP-Optimize until this point! Layout, branding and links have been altered to reflect this change.
* RE-FACTOR: Internal code completely re-factored, laying the foundations for future improvements
* TWEAK: Various filters introduced internally for easier customisation
* TWEAK: Marked form element labels, so that they can be clicked
* TWEAK: Various small UI improvements (more to come in future releases)
* FIX: Previous versions could potentially run OPTIMIZE commands on tables in the same MySQL database (if it was shared) belonging to other sites
* FIX: Previous versions were not deleting most delete-able transients. This is now fixed, with the modification that we now delete all *expired* transients.
* LANGUAGES: Removed language packs and screenshots that are already carried by wordpress.org, reducing the plugin download / install size

= 1.9.1 =
* Ability to clean up Unused Post Meta, Comment Meta and Broken Relationship Data
* Warning prompts for RED marked items and optimize button
* Better transient options cleaning.
* Language files update
* Various other fixes

= 1.9 =
* 27 Weeks retention option equivalent to 6 month
* Compatibility update.
* Language files update
* Removed email notifications, it doesn't work on many servers
* Various other fixes

= 1.8.9.10 =
* Security Patch provided by Dion at WordPress.org and Security report provided by http://planetzuda.com .
* Language files update

= 1.8.9.8 =
* Daily Schedule Option Added
* Email notification on automatic optimization, default email is admin email address. You can change this in settings

= 1.8.9.7 =
* BUGFIX for Settings screen
* Enable/Disable trackbacks / comments buttons removal and use select box instead. Extra button caused the Auto Scheduler to get into reset mode.

= 1.8.9.6 =
* There were few number formatting problem and detection of InnoDB table format. Charles Dee Rice solved the problems that I missed out. Thank you!
* Duplicate msg fixed
* Enable/Disable trackbacks for all published post
* Enable/Disable comments for all published post

= 1.8.9 =
* ONE MILLION+ Downloads. THANK YOU!!
* Language updates platform - see readme file for details.
* Mixed type tables optimization supported and in BETA
* Removal of akismet metadata from comments
* Removal of other stale metadata from comments
* InnoDB tables won't be optimized.
* Main screen user selection will be saved. Red items selection will not be saved
* Scheduled time display will be shown according to WordPress blog local time

= 1.8.6 =
* Language files update
* Fix issues with total gain number problem
* InnoDB tables detected and features disabled automatically, tables view will not show Overhead. Main view will not show space saved, or total gain.

= 1.8.5 =
* Version bump + modified translator names

= 1.8.4 =
* Problem with readme file changes

= 1.8.3 =
* Minor fixes

= 1.8.1 =
* A whole lot more code optimization
* Slick new interface
* Responsive mobile interface, supports running from iPhone/Android/Tablets
* Tables moved to independent tab
* Optimize faster
* GitHub updater support
* I do not monitor WP forums, support email at plugins(at)ruhanirabin.com

= 1.7.4 =
* More Translation compatibility.
* Added MYSQL and PHP versions beside the Optimizer tab.

= 1.7.3 =
* Fixed Problems with wpMail.
* Fixed Problems with wpAdmin menubar.
* Fixed Permission issues on some site.
* Language files update

= 1.7.2 =
* All MySQL statements re-factored into native WP database calls - necessary for future versions of MySQL and WordPress.
* Upgrade to match WordPress 3.9 changes.
* Language files update
* Now postmeta cleanup is disabled from code - it will be updated soon with native WordPress postmeta cleaning options.

= 1.6.2 =
* Language files update

= 1.6.1 =
* Fixed - trashed Comments was not clearing out.
* Language files update

= 1.5.7 =
* Language files update

= 1.5.6 =
* "Unused Tags cleanup" option made a problem on some WordPress sites that it deletes empty categories. Since I am unable to replicate this problem. I am making this option disabled.
* Language files update
* Minor maintenance and fixes.

= 1.5.5 =
* Safe clean up options are selected by default, defaults are not by user preference for now (Optimizer Page).
* All the potentially dangerous clean up options are MARKED RED.
* Language files update
* New features explained - http://j.mp/HBIoVT (read the blog post).

= 1.5.4 =
* More path related fixes for various warnings. Maintenance

= 1.5.2 =
* Fatar error fix, if it disabled your wp admin, please remove the wp-optimize directory and reinstall again.

= 1.5.1 =
* Option to add or remove link on wp admin bar (even enabled - it is visible to admin only).
* New admin interface.
* Settings to select items for automatic optimization.
* Removal of WordPress transient options
* Removal of orphaned post meta tags.
* Removal of unused tags.
* 3 different schedule times added (weekly, bi-weekly and monthly).
* Language files update
* Code optimization and translation strings updated.
* Integrated development log from TRAC

= 1.1.2 =
* removed persistent admin bar menu item
* Language files update

= 1.1.1 =
* Fix Fatal Error.

= 1.1.0 =
* Added WP-Optimize to admin menu bar on top. Always accessible.
* Added wp-optimize.pot file for translators (inside ./languages/ folder).
* Last auto optimization timestamp / display
* Fix possible scheduler bug as requested at support forum
* Fix some other codes regarding SQL query parameters
* Ability to keep last X weeks of data, any junk data before that period will be deleted - this option affects both Auto and Manual process. Appreciate time and help from Mikel King (http://mikelking.com/) about this matter.

= 1.0.1 =
* Removed auto cleanup of trackbacks or pingbacks.. it's better for people to do it manually.

= 0.9.8-beta =
* added beta tag

= 0.9.8 =
* Remove all trackbacks and pingbacks (can significantly reduce db size)
* Remove all Trash Comments and Posts
* Enable/Disable weekly schedules of optimization. This is an EXPERIMENTAL feature. It may or may not work on all servers.

= 0.9.4 =
* Non Initialized variables fixes as of https://wordpress.org/support/topic/plugin-wp-optimize-errors-in-debug-mode?replies=2

= 0.9.3 =
* Removed security tools.
* Full database size displayed

= 0.9.2 =
* Now the plugin is visible to site administrators only. Authors, Contributors, Editors won't be able to see it.

= 0.9.1 =
* Fixed problem with database names containing "-" .
* NEW Main Level Menu Item added for WP-Optimize, You might need to scroll down to see it
* Compatibilty with WordPress 3.1
* Language files update
* Added auto draft post removal feature

= 0.8.0 =
* Added Multilanguage capability
* Language files update

= 0.7.1 =
* POST META Table cleanup code removed cause it is making problems with many hosts

= 0.7 =
* Added cleanup of POST META Table along with the revisions
* Fixed some minor PHP tags which causes the total numbers to disappear
* Now requires MySQL 5.1.x and PHP 5.1.x

= 0.6.5.1 =
* Fix Interface

== Upgrade Notice ==
* 3.0.13: Cache feature to add a Purge all cache button to the admin bar. Premium fetures to Prevent php warning in scheduled optimisations list. Premium Unused images feature to Add compatibility with Advanced Custom Fields (ACF) image and gallery fields.