Pull Request for Issue #36741 .

DO NOT USE THE PATCH TESTER TO TEST THIS PULL REQUEST

This Pull Request includes changes in the JavaScript. The Patch Tester component DOES NOT support Joomla 4 PRs with changes in the JavaScript or the vendor folder as these items are NOT included in the repository; they are rebuilt when the Joomla build script runs before a release. You MUST use the pre-built packages, or build your own packages. Always start with a NEW site to avoid browser caching issues — especially pertinent if you've already tested another Joomla 4.3.0 development PR in your testing site!

To build your own packages, start by checking out this PR in a branch, let's say feature/jupdate-chunked-j4.

Then open a console and run, go into the build directory and run php ./build.php --remote=feature/jupdate-chunked-j4 --exclude-gzip --exclude-bzip2

This will check out the branch you created into a temporary folder in build/tmp, build Joomla (you need Composer and npm available in your path), and come up with packages in build/tmp/packages. Use the Joomla_4.3.0-dev-Development-Full_Package.zip to install a site for testing purposes.

Summary of Changes

You can now tell Joomla Update to download the upgrade packages one chunk at a time (default: 10MiB; can be as low as 256KiB and as high as 20MiB). This allows the update to download on very slow servers, as per the linked issue.

The default is to enable chunked download with a chunk size of 10MiB and a 2 seconds wait time between chunk downloads. On the vast majority of sites the update will run at the same speed or about 2 seconds slower. On local sites and slow servers which previously struggled with upgrades this will allow updates to work properly. For the remaining servers and local sites, users will have to edit the Joomla Update options to lower the amount of data downloaded per page load (most of them will find 1MiB to be just about right).

This is a port of #38774 to Joomla 4.3. The former will not be merged into J3. This PR was requested by @obuisard on behalf of the production leadership.

Testing Instructions

Common instructions

• Install a new site
• Apply the patch
• Change the manifest_cache in the #__extensions table for the extension with name = files_joomla to have a fake version, e.g. 4.2.0. This requires editing its manifest_cache to read, for example, {"name":"files_joomla","type":"file","creationDate":"2022-07","author":"Joomla! Project","copyright":"(C) 2019 Open Source Matters, Inc.","authorEmail":"admin@joomla.org","authorUrl":"www.joomla.org","version":"4.2.0","description":"FILES_JOOMLA_XML_DESCRIPTION","group":""}
• Change the libraries/src/Version.php to have the same version number.
• Log into the site's backend
• Go to Components, Joomla Update

Test 1

Makes sure that updates without any further configuration still work (with chunked downloads).

• Follow the Common instructions
• Click on Check for Updates
• An update is found
• Click on the button to install the update
• You wait for a while, the progress bar moves two or three times until it reaches 100% and the update installation starts.

Test 2

Makes sure that non-chunked downloads work.

• Follow the Common instructions
• Click on Options
• Click on Fine-tuning
• Set Chunked Downloads to No
• Click on Save & Close
• Click on Check for Updates
• An update is found
• Click on the button to install the update
• You will see the progress bar jump to 100%.

Test 3

Makes sure the fine-tuning settings work.

• Follow the Common instructions
• Click on Options
• Click on Fine-tuning
• Set Chunked Downloads to Yes
• Set “Minimum time between download steps (seconds)” to 5
• Set “Download size per page load” to 256 KiB
• Click on Save & Close
• Click on Check for Updates
• An update is found
• Click on the button to install the update
• You will see the progress bar move every 5 seconds or more, downloading about half percent of the update at a time. The download is substantially slower (excruciatingly slower!) than test 2.
• Once the download is complete the progress bar shows 100%, and the update installation starts.
• You can redo this test with the minimum time set to 0 and observe that the download is much faster — unless your server throws an error because of too many requests…

Link to documentations

Please select:

• Documentation link for docs.joomla.org: Joomla Update help page
• No documentation changes for manual.joomla.org needed

In docs.joomla.org the following section needs to be added

Updating Joomla on local sites and slow servers

Joomla needs to download a rather big update ZIP package from Joomla's update servers. The size of the package depends on the version you're currently on and which is the latest version. Update packages can be as small as 1 MiB for small updates between consecutive patch versions (e.g. 1.2.3 to 1.2.4) or as big as around 30 MiB when upgrading to a new major version.

The Joomla Project is using a variety of file hosting platforms to make sure that these downloads are generally speedy. However, the download may not be going very fast because of a network issue, or simply because the server is behind a slow connection (as is the case with sites installed on your local computer if your Internet connection has a low speed or is on a congested network). To work around this problem, Joomla Update starting with Joomla 4.3.0 downloads the updates in smaller chunks and waits a little bit between each successive download. When all chunks are downloaded the update proceeds as per usual.

By default, Joomla downloads 10 MiB at a time and waits 2 seconds between each download. You can change that by going to System, Update, Joomla, clicking on the Options button, and going to the Fine-tuning tab. You will find the following options:

• Chunked Downloads. Set to No to disable the chunked downloads feature. This will tell Joomla to try to download the entire update package in one go. This is only recommended if you are on a server with a very fast inbound connection.
• Download size per page load. How much of the update you want to download at a time. The default is 10 MiB. If you are on a slow connection try 1 MiB or less. The lower this value, the longer it takes to download the update, but the less likely it is that the download will time out or otherwise fail. If you are on a fast connection, use higher values. Higher values will finish downloading the update faster, but it's more likely that the download will time out or otherwise fail if there is a network issue which makes the download slow down.
• Minimum time between download steps (seconds). How much time you want Joomla to wait between two successive downloads of an update package chunk. If you have a very fast server which also applies rate limiting to requests —either directly, or through a third party service such as CloudFlare— the successive requests to download the next chunk of the update package may come “too fast” and the server (or third party service) might block them. This would make the update download fail. To prevent that, Joomla adds a bit of “sleep” time, doing absolutely nothing between successive downloads. If you see the progress bar moving really fast before receiving an “unknown error” message increase this time — you can set it up to 10 seconds which is very conservative. If your server doesn't seem to have rate limiting enabled or is really slow, therefore it takes a long time for the progress bar to move, lower this setting to 0 to make the Joomla Update a tad faster when downloading the update package.

Remember, you cannot go wrong with these settings! If the download fails you can tweak these settings are described above until the download completes. Before the download completes there is absolutely no change made to your site. Therefore it's safe to change these settings, even if it takes several tries to get a successful download. Nothing on your site breaks by tweaking these settings.

Translation Changes Required

This PR introduces 19 new language strings.