Last month, Microsoft announced the end of support date for Power BI Desktop on Windows 8.1. Recently, TypeScript support and other new features have been introduced to the tech giant’s premier data analytics platform.
Today, a new one The Tabular Model Definition Language (TMDL) is unveiled. For Power BI, now available in public preview.
The need for TMDL arose because of the highly complex BIM files extracted from large, semantic data models created using Power BI. Traditionally containing model metadata in Tabular Model Scripting Language (TMSL), this file is considered too difficult to process further. Moreover, collaboration in the form of multiple developers working on the same model can also be quite a difficult process.
TMDL, meanwhile, introduces the following methods to overcome the limitations of TMSL:
- Human-readable format using a YAML-like syntax. Each tabular metadata object has a textual representation with minimal delimitations. Hints are used to represent parent-child relationships between objects.
- An improved editing experience, especially for properties containing DAX and M expressions.
- A standard folder output format where each model object is represented as an individual file, makes TMDL suitable for more source control-friendly collaboration.
For now, the TMDL model allows metadata to be serialized as multiple text files, as well as reading a folder containing TMDL text files and converting it back to a suitable Tabular Object Model (TOM). In the future, Microsoft plans to release open source VS Code extensions for a better TMDL editing experience. The tech giant will also integrate TMDL into more Microsoft tools, with adoption currently supported for all community-developed tools that write tabular model metadata files.