This documentation is not using the current rendering mechanism and will be deleted by December 31st, 2020. The extension maintainer should switch to the new system. Details on how to use the rendering mechanism can be found here.
This chapter describes some internals of the Resize Images Automatically extension to let you extend it easily.
Signals and Slots¶
The concept of signals and slots allows for easy implementation of the Observer pattern in software, something similar to hooks in former versions of TYPO3. Its implementation in TYPO3 CMS has been backported from Flow, so please read chapter Signals and Slots from Flow official documentation. In short, signals are put into the code and call registered slots when run through.
Available signals and slots: