What's the best way to site specific configuration in a multisite TYPO3 installation? - typo3

Question

We have a TYPO3 9.5 installation with a bunch of different websites in it.
We want to store some custom configurations for each site (eg. show phone number in footer yes/no and something like this) and give the editors the possibility to change this in a simple way in the backend.
It would be nice if we can store these properties on the rootpage of each site but be able to overwrite (some) properties on sub pages if needed.
Similar to the page properties that fluidtypo3/flux brings.
Is there a possibility to achieve this with TYPO3 core and a custom extension? Eg. by extending the page table or adding custom table?

Answer 1

You need to differ between a site configuration and regular pages!
The site configuration is valid for the full site, so for every page
A page can be different on a page level
Both use cases are valid, so let's explain in detail
Extending the site configuration
The site configuration can easily be extended by creating the file <site-extension>/Configuration/SiteConfiguration/Overrides/sites.php
<?php
defined('TYPO3_MODE') || die('Access denied.');
call_user_func(
function ($table) {
$GLOBALS['SiteConfiguration'][$table]['columns']['trackingCode'] = [
'label' => 'Label',
'config' => [
'type' => 'input',
'eval' => 'trim',
'placeholder' => 'GTM-123456',
],
];
$GLOBALS['SiteConfiguration'][$table]['types']['0']['showitem'] .= ',--div--;Extra,trackingCode';
},
'site'
);
The value of the new field trackingCode can then be easily fetched, e.g. by TS with data = site:trackingCode. As an alternative you can also use the SiteProcessor to get access to the site configuration in a FLUIDTEMPLATE.
Extending pages
Create the file <site-extension>/Configuration/TCA/Overrides/pages.php
<?php
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTCAcolumns(
'pages',
[
'trackingCode' => [
'exclude' => true,
'label' => 'A label',
'config' => [
'type' => 'input',
]
],
]
);
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addToAllTCAtypes(
'pages',
'--div--;Extra, trackingCode'
);
and `ext_tables.sql``
CREATE TABLE pages (
trackingCode text NOT NULL
);
and you get access to the field with TypoScript and within FLUIDTEMPLATE with {data.trackingCode}.
Using slide
By adding trackingCode to the comma separated list in [FE][addRootLineFields] (use the Install Tool > Settings > Configure Installation-Wide Options it is possible to override the value for all subpages.
The following TypoScript will get up the rootline and return the 1st value set.
lib.code = TEXT
lib.code.data = levelfield:-1,trackingCode, slide