What are “signals/slots” and how do you use them? (2)
Signals notify developers about security risks in their code
The signal/slot concept can be used to extend TYPO3 core functionality
The signal/slot dispatcher is required to emit a signal
Slots are an abstract instance of a signal class
What are “signals”? (1)
Signals are classes located in directory Classes/Signals/
Signals are used to write entries to the internal log
Signals are building blocks for domain driven design
Signals are used to connect external data sources to Extbase
Signals are emitted by the TYPO3 core or by extensions to extend existing functionality
What are typical benefits of “signals/slots”? (2)
Signals/slots extend the TYPO3 core without the need to edit core files
Signals/slots are meant to simulate SQL procedures using pure PHP code
Signals are never marked deprecated and will remain in the TYPO3 core forever
One signal can trigger multiple slots
How do you connect a slot to a signal when using TYPO3’s SignalSlotDispatcher? (1)
join()
connect()
attach()
insert()
slot()
Which statements about XCLASSes are correct? (2)
XCLASSes prevent cross-site scripting (XSS) attacks
XCLASSes extend core classes and/or overwrite core methods
XCLASSes need to be registered in the file Configuration/Overrides/xclasses.php
XCLASSes need to be registered in the following global array: $GLOBALS['TYPO3_CONF_VARS']['SYS']['Objects']
XCLASSes replace files from TYPO3 source package which possibly impacts the TYPO3 update process
What are typical limitations of XCLASSes? (3)
XCLASSes only work on core classes that are instantiated using the GeneralUtility::makeInstance() method
XCLASSes do not work on static classes, static methods or final classes
There can only by one XCLASS per base class
XCLASSes only work in Composer-based TYPO3 installations
The visibility of all properties of an XCLASS must be private