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This extension is of course the basic brick of the Tesseract architecture. On top of a general documentation, it provides TYPO3 services for each of component types used by Tesseract (controller, data provider, data consumer, data filter), PHP interfaces for defining the API and some utility classes.
This extension is a tool box designed to simplify work with language overlays. On the one hand it provides very general methods which make it easy to retrieve properly overlaid records. On the other hand it also provides a number of very basic methods that handle such tasks as assembling the proper language fields conditions in a SQL statement, based on TCA definitions. It is used by dataquery to provide full support for translations.
This extension can be used outside of the Tesseract context.
This extension provides a library inspired by TypoScript's getText function. It makes it possible to retrieve values from a variety of sources with a simple syntax and provides a simple API for parsing strings containing such expressions. Retrieved values can also be post-processed by functions, which make it possible, for example, to quote strings to that they are safe to use inside a SQL query.
The expression parser is at the heart of the datafilter extension. It is also used by several other Tesseract components.
It also be used outside of the Tesseract project.
It is often desirable to define contexts in parts of a web site. For example one part of the page tree might be about a given city, while another branch covers a different one. In such cases the context extension provides a TypoScript-driven way of defining values that can be easily picked up in Data Filters via the expressions mechanism.
This extension can also be used outside of the Tesseract project.
There's a small extension that makes it easy to test expressions: expressions_sandbox. It comes as a FE plugin where expressions can be simply tested. As it's purely useful to development, it is not published in the TER, but can be grabbed from Forge: forge.typo3.org/projects/show/extension-expressions_sandbox