# T3DataStructure¶

TYPO3 offers an XML format, T3DataStructure, which defines a hierarchical data structure. In itself the data structure definition doesn’t do much - it is only a back bone for higher level applications which can add their own configuration inside.

Such applications can be:

• FlexForms - a TCEform type which will allow users to build information hierarchies (in XML) according to the Data Structure. In this sense the Data Structure is like a DTD (Document Type Definition) for the backend which can render a dynamic form based on the Data Structure;
• TemplaVoila! - an extension which uses the Data Structure as backbone for mapping template HTML to data.

This documentation of a data structure will document the general aspects of the XML format and leave the details about FlexForms and TemplaVoila to be documented elsewhere.

Some other facts about Data Structures (DS):

• A Data Structure is defined in XML with the document tag named “<T3DataStructure>”
• The XML format generally complies with what can be converted into a PHP array by GeneralUtility::xml2array() - thus it directly reflects how a multidimensional PHP array is constructed.
• A Data Structure can be arranged in a set of “sheets”. The purpose of sheets will depend on the application. Basically sheets are like a one-dimensional internal categorization of Data Structures.
• Parsing a Data Structure into a PHP array is incredibly easy - just pass it to GeneralUtility::xml2array() (see the Parsing a Data Structure section).
• “DS” is sometimes used as short for Data Structure

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