Make Matomo compatible with PHP 7.4

[Findus23]

similar to #13418

Status:

All Warnings in Matomo itself and the broken Twig rendering are fixed in Matomo 3.12. All remaining warnings depend on third-party libraries (see below).

Soon PHP 7.4 will be released (RC 1 is planned or September 5th), so it would be great if Matomo would work mostly fine when it is released.

I set up a Matomo instance using the latest beta4 at https://matomo-beta.lw1.at
If you want to get access, just message me.

Current status is that Matomo is nearly completly unusable as it renders invalid HTML with missing whitespaces:

<ul class="right hide-on-med-and-down"><li role="menuitem" class="active"><atitle="Zeige Webanalytik Berichte für Testsite."                  id="topmenu-corehome"
                  href="index.php?module=CoreHome&amp;action=index&amp;idSite=1&amp;period=day&amp;date=yesterday"               target="_self" tabindex="3">Dashboard</a></li><li role="menuitem" class=""><atitle="Vergleichen Sie Webanalytikstatistiken für alle Ihre Websites."                  id="topmenu-multisites"
                  href="index.php?module=MultiSites&amp;action=index&amp;idSite=1&amp;period=day&amp;date=yesterday"               target="_self" tabindex="3">Alle Websites</a></li><li role="menuitem" class=""><atitle=""                  id="topmenu-tagmanager"

This seem to be caused by a required change in Twig (twigphp/Twig@1fb0f97), so updating to twig 1.41.0 or later should solve this.

[Findus23]

One more bug that breaks archiving: (appears as a response in archiving)

PHP Deprecated:  Array and string offset access syntax with curly braces is deprecated in /var/www/matomo-beta/libs/upgradephp/upgrade.php on line 180 PHP Deprecated:  Array and string offset access syntax with curly braces is deprecated in /var/www/matomo-beta/libs/upgradephp/upgrade.php on line 194 PHP Deprecated:  Array and string offset access syntax with curly braces is deprecated in /var/www/matomo-beta/libs/upgradephp/upgrade.php on line 194 PHP Deprecated:  Array and string offset access syntax with curly braces is deprecated in /var/www/matomo-beta/libs/upgradephp/upgrade.php on line 200 PHP Deprecated:  Array and string offset access syntax with curly braces is deprecated in /var/www/matomo-beta/libs/upgradephp/upgrade.php on line 202 

matomo/libs/upgradephp/upgrade.php

Line 180 in 7ef8926

if ($line{0} == '[') {

I don't know what that line means, but I am also confused why this function is here when Matomo is using a custom ini parser.

Update: It seems to just be a weird way of writing if ($line[0] == '[') {

[Findus23]

One more warning in the log:

/var/www/matomo-beta/core/DataTable/Filter/ColumnDelete.php(164): Deprecated - array_key_exists(): Using array_key_exists() on objects is deprecated. Use isset() or property_exists() instead - Matomo 3.11.0

matomo/core/DataTable/Filter/ColumnDelete.php

Line 164 in b16a791

if (!array_key_exists($column, $row)) {

[Findus23]

Another occurrence of the braces will be fixed with leafo/lessphp#647 (if it gets merged as the last release was 5 years ago)

Update: This one is going to be fun to fix as the latest lessphp requires PHP 5.6+: leafo/lessphp@18b8f29

[Findus23]

Two more deprecation warnings in tcpdf will be fixed with
tecnickcom/TCPDF#123
and
tecnickcom/TCPDF#131

[Findus23]

Another potential bug (but I don't think it happens in Matomo and is only very minor):
davaxi/Sparkline#10

[mattab]

@Findus23 Thanks for creating the issue! 👍 What is the status of PHP 7.4 compatibility now?

[Findus23]

@mattab I think all remaining issues are in third party libraries as mentioned above. And Matomo won't be completly ususable as of now.
But I don't have a great solution for updating those.

[diosmosis]

Looks like the only package that needs to be updated is lessphp, but that does not have a release w/ the fix. I suppose we could fork it as well or wait until matomo 4.

[tsteur]

We'd need to fork it in this case since we can't wait to Matomo 4 unfortunately.