How can I set the icon for a content element in TYPO3? - typo3

Question

In tt_content I have added something like this, and set the core icon 'content-image':
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTcaSelectItem(
'tt_content',
'CType',
[
'My Element',
'myelement',
'content-image'
],
'textmedia',
'after'
);
And this works in the 'Type' dropdown menu. However, when in Page or List view it always shows the default text icon. How do I change this to match the type menu?

Answer 1

Just found another question with a real good answer - mainly the same
as mine, but better structured - have a look:
How to setup icons for content elements or plugins in a TYPO3 extension
You may revisit https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ApiOverview/ContentElements/AddingYourOwnContentElements.html with a full overview.
The \TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTcaSelectItem() registers the icon only for the select field.
For the "new content element" wizard you have to provide a proper TSconfig part https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ApiOverview/ContentElements/AddingYourOwnContentElements.html#add-it-to-the-new-content-element-wizard
// example - you must adopt for your element
mod.wizards.newContentElement.wizardItems {
// add the content element to the tab "common"
common {
elements {
examples_newcontentelement {
iconIdentifier = content-text
title = LLL:EXT:examples/Resources/Private/Language/locallang.xlf:examples_newcontentelement_title
description = LLL:EXT:examples/Resources/Private/Language/locallang.xlf:examples_newcontentelement_description
tt_content_defValues {
CType = examples_newcontentelement
}
}
}
show := addToList(examples_newcontentelement)
}
}
If you want to use a custom image, you have to register it. Either in ext_localconf.php with proper icon calls or depending on the core version with the simple Configuration/Icons.php file.
See for 11.5+ https://docs.typo3.org/m/typo3/reference-coreapi/main/en-us/ApiOverview/Icon/Index.html or before see https://docs.typo3.org/m/typo3/reference-coreapi/10.4/en-us/ApiOverview/Icon/Index.html
The next part is then TCA configuration for the specific table. Generic table icon file is configured with:
// or $GLOBALS if done as TCA Override for a existing table
return [
// ...
'ctrl' => [
'iconFile' => '',
// ...
],
// ...
https://docs.typo3.org/m/typo3/reference-tca/main/en-us/Ctrl/Properties/Iconfile.html
Table with types can have different icons per types, which can be set with typeicon_classes
https://docs.typo3.org/m/typo3/reference-tca/main/en-us/Ctrl/Properties/TypeiconClasses.html#ctrl-reference-typeicon-classes - however, this depends on the type field. For tt_content this is "CType". So this helps only for real content elements which registeres as own CType - and not as list CType with a subtype list_type. For extbase plugin this is done with the proper plugin registration in Configuration/TCA/Overrides/tt_content.php:
\TYPO3\CMS\Extbase\Utility\ExtensionUtility::registerPlugin(
'ExtkeyInCamelCase',
'PluginIdentifier',
'plugin title',
// icon
'my-icon');