.. ================================================== .. FOR YOUR INFORMATION .. -------------------------------------------------- .. -*- coding: utf-8 -*- with BOM. .. include:: ../Includes.txt .. _developer-manual: Developer Manual ================ 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: .. toctree:: :maxdepth: 2 PostProcessingImages